Go Back   JeepBBS > Discussion Battleground > Jeep Friends Forum

Jeep Friends Forum This is a forum for jeep friends to hang out. For more formal atmosphere hop over to the Technical Forum

Reply
 
Thread Tools Rating: Thread Rating: 19 votes, 5.00 average. Display Modes
  #31  
Old 04-07-2004, 06:14 AM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Step 10 ? Replace the Fuel Injectors:

A new set of Fuel Injectors come with the Super Charger kit. They are larger then the stock injectors and therefore capable of flowing more fuel, in the same amount of time, then the stock units can.

The extra fuel is needed to maintain the correct Air Fuel ratios given the Blower will be pumping a lot more air into the engine.

What size injectors are they? (Why did I know you would ask that question? Cause everyone does! )

I believe but do not know that they are 28# Ford units. When Jack gets back from Moab I will call and find out.



WARNING Potential to Blow yourself Up! You are going to be opening up the fuel system of your Jeep. Take all necessary precautions so that you DO NOT blow yourself up by igniting the gas vapors in your shop!
  • Open the doors for ventilation in your shop
    If you smoke, stop during this step
    Shut off all open flame heaters and any spark generated electrical devices
    Etc.

Gas fumes explode folks, and if they explode on you, you won?t be able to read the rest of my boring write-up! (Read that; Don?t let this happen to you!)




Here are the tasks I did in the order I did them..

Make sure the battery is disconnected.

Find some high quality tape and an indelible ink (Sharpie) marking pen and label each of the fuel injector wiring harness plugs.

Start at the front of the engine with #1 and finish up in the back with #8.
(Just seeing if you are really reading this and paying attention, or if you need more sleep at night! There are only 6 injectors on the 4.0L engine and four injectors on the 2.5L)





Once you have all the injector harness plugs labeled, unplug all the injectors.



Relieve the fuel system pressure;
  • Remove the gas tank filler cap
    Remove the plastic cap from the Fuel Rail Pressure Test Port
    Put a shop towel under the Test Port
    Connect your Fuel Pressure Gauge to the Test Port
    Put a ?catch? can under the gauge exhaust port
    Press the relief button on the gauge and catch the gas


Here?s a picture.





You will probably get about 3 ounces of gas in the catch can. Please do something with it now. Don?t leave it in the shop to evaporate and increase the odds of a big bang!

  • Remove the Pressure Gauge from the Test Port
    Put the Plastic cap back on the Test Port
    Put the Gas Tank Cap back on.



Disconnect the Fuel Line at the Fuel Rail:

Using compressed air blow away any dirt from around the Fuel Line to Fuel Rail fitting.

While you?re at it do the same around each of the Fuel Injectors where they enter the Intake Manifold.

Put a shop towel under the Fuel Line to Fuel Rail fitting.

This Fuel Fitting is called a ?Latch Clip Fitting?.

You will need a 5/16-inch (or 8mm) Fuel Line Disconnect Tool (NAPA $5) to release it.

DO NOT attempt to release this fitting with a screwdriver! (I promise you, you will be replacing fuel line if you do!)


This is a two-part fitting. The outer clip can be pried off with a screwdriver!





Save the clip, you will need it later to put this fitting back together.

Place the 5/16-inch (8mm) Fuel Line Disconnect Tool around the fuel line and push it into the fitting. This will release the plastic clips inside the fitting and allow you to separate the Fuel Line from the Fuel Rail.




Sorry I know this picture is very poor.

Please be prepared. Some gas will dribble out when the fitting is released.

Do something with the shop rag that just became soaked with gas, preferably outdoors.



Remove the Fuel Rail and Injector Assembly:

The injectors are held in place, sandwiched, between the Intake Manifold and the Fuel Rail.

The Fuel Rail is held in place with four (4) 10mm bolts, which you need to remove now.

Once these four bolts are out, remove the fuel rail, with injectors attached by ?gently? rocking it back and forth while pulling up on the assembly.

It will come out, but do not force things. Be gentle but firm!

You might want to be prepared with an outdoor work area prior to removing the fuel rail and injectors assemble from the engine to keep gas fumes in your shop as low as possible.

Here is what the Fuel Rail / Injector Assembly looks like sitting on a cardboard box outdoors because I wasn?t prepared with a work surface.






Remove the Fuel Injectors:

The Fuel Injectors are held to the Fuel Rail with small metal clips.

Remove the clip from each injector with a plier, then gently wiggle the injectors while you pull each one out.

Here is a picture showing two injectors de-coupled from the fuel rail and the clips.




Do not loose the metal clips. You will need them for the new injectors.



Where in the World are the ?O-Rings?:

Each injector has two ?O-rings?, one on the fuel rail end and one on the intake manifold end.

It is not uncommon for an ?O-ring? to remain in the Manifold or the Fuel Rail when you remove the injectors.

You have to find and account for all of them. If you don?t they will find you later when you go to put things back together.



Clean Intake Manifold and Fuel Rail Ports:

Take a good look inside the ports (holes) where the Fuel Injectors mount. If your Jeep has any significant mileage like mine, you will probably find a ?gummy varnish buildup? in there.

While I don?t know for sure, I believe this is caused by a dab of grease that is put on the Injector O-rings during assembly to help seat them in place. (You will be doing this too later to seat the new injectors.

I think this grease bakes in place over time forming the gummy stuff.

You need to clean this out to ensure the new injector ?o-rings? will seat and seal without any leaks.

Go raid your bathroom medicine chest for some ?Q-tips?. (If they are not in the medicine chest try the cabinet under the sink or the hall closet.)

Soak the end of a Q-tip with Carburetor Cleaner and work this gummy deposit out of each port in the fuel rail and the intake manifold.




(Don?t get ?cheap? on me now. When the q-tip starts to get dirty or the cotton end starts to come loose throw it away and grab a new one. Heck they give you about 4-gazillion ?Q-tips? per package for about 2 bucks at Wal-mart.



Install the New Injectors in the Fuel Rail:

There is a grove cut around one end of the injectors to fit the metal locking clips. This is the end that goes into the Fuel Rail.

Put a small dab of grease, or clean motor oil in the O-ring on the injector and slowly push a new injector into the fuel rail. DO NOT twist and turn the injector as you do, or you run the risk of nicking the O-ring and this WILL cause a leak.

Note: If you do nick an o-ring DO NOT use one off the old injectors, it will leak. Run over to NAPA and for 15 cents buy a new one. Heck for 15 cents and your proven ability to nick an o-ring already maybe you should be like me and buy 4 or 5 of them.


Just lubricate the O-ring and push it straight in.

Once seated, install the metal locking clip to the fuel rail and injector and move on to the next injector till they are all installed and secured to the fuel rail.





See that o-ring and the little black mark at 5 o?clock to the o-ring? That?s what a nicked o-ring looks like!

Make sure all the injector plugs are facing up so they can be plugged into the wiring harness once installed.



Install the Fuel Rail / Injector Assembly:

Place a small dab of grease around the o-ring on each injector and then press the injectors into the Intake Manifold as an assemble.

Do this carefully. Gently rock it back and forth while applying pressure downward. It will pop in place.

Make sure all injectors are seated all the way into the Intake Manifold..

Bolt the Fuel Rail down to the Intake Manifold using the four 10mm bolts and torque them down to 100 In/Lbsof torque. Be Careful, that is INCH Pounds, NOT Foot Pounds of torque!

Reconnect the Fuel Line to the Fuel Rail by sliding the Fuel Line Fitting over the nipple on the Fuel Rail. It will give you a positive ?Click? when fully engaged.

Re-install the ?safety clip? on this fitting.

Plug the 6 injector wiring harness plugs onto the correct injectors. (Read your labels.)

The new injectors are installed and all that is left it to check for leaks.






Check for Leaks:

Reconnect your battery and pressurize the fuel system by turning the Ignition Key On and OFF several times. Each time you do this the fuel pump will run for bout 2 seconds. This will pressurize the fuel system.

Carefully check the Fuel Line to Fuel Rail fitting for leaks.

Also check the Fuel Rail to Injector Ports for leaks.

All should be fine, but if you find a leak now is the time to resolve the issue, not later.



The new, larger Fuel Injectors are now installed and ready to go. Check this task off your To-Do list.



Frank
Reply With Quote
  #32  
Old 04-07-2004, 08:59 AM
Jeff Weston Jeff Weston is offline
Can I get a mint julep with that?
 
Join Date: Aug 2001
Location: Alpharetta, GA
Posts: 3,091
Excellent writeup as always Frank!
__________________
Jeff
Reply With Quote
  #33  
Old 04-07-2004, 09:40 AM
Robert J. Yates Robert J. Yates is offline
Registered User
 
Join Date: May 2001
Location: planet earth
Posts: 6,212
Quote:
Originally posted by Daless2
PCM Fast Learn Mode

I think most people know that the PCM performs several functions controlling Air Fuel ratios via Injector Pulse Width and Ignition Timing.

These ?outputs? are controlled using the ?inputs? received from all the sensors and then comparing these reading against a set of data tables burned into the PCM.

These ?memory tables? are the brains that keep the engine running at low emissions and peak economy across the RPM band

What most people don?t know is that these memory tables change. They are ?adaptive?, based on sensor readings, driving habits, engine performance and sensor tolerances.

Over time, the PCM Memory Tables become tuned to your engine.

Most folks know that disconnecting the battery for 15 to 20 minutes will reset the PCM to get rid of a Ceck Engine Light or Error Codes stored in the PCM.

However this DOES NOT reset the Adaptive Memory Tables in the PCM. Until recently I did not know how to do this.


This procedure first came to me from the folks at Avenger. I then verified it with a phone call to a Chrysler Engineer who had called me a year or so ago to ask about my experiences with a certain part on my TJ. I figured he owned me a favor. He had to check up on this for me. He called me back a week later and did indeed verify this procedure and what it does.

To the best of my knowledge it isn?t documented in any of the FSM.



Forced Flash

This very simple procedure will Erase the ?Adaptive Memory? stored inside the TJ PCM and allow a new ?Adaptive Memory? to be developed.

After performing this procedure the PCM will re-learn and store into Adaptive Memory your engines performance characteristics.
  • 1.Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.)
    2.Reconnect the Battery Cable
    3.Turn Ignition Switch to the ?On? position but DO NOT start the engine
    4.Turn Headlight ?On?
    5.Turn Headlights ?Off?
    6.Turn Ignition Key ?Off?

The Adaptive Memory has now been flashed, or erased from the PCM.

When you start the engine it will be running off a set of pre-programmed tables that come with the PCM from the factory.

When you get the engine up to operating temperature the PCM will start to collect data for the ?Adaptive Memory?.

The PCM will collect data for Adaptive Memory for the first 50 Warm-up Cycles.


Warm-up Cycle

A warm-up cycle happens when all of the following conditions exist.
  • 1. Engine is running
    2. A raise of 40F in engine temperature must occur ABOVE the engine temperature at start-up
    3. Engine Coolant Temp must reach at least 160 F.


Once your engine has gone through 50 warm-up cycles in at least a 500-mile distance the PCM adaptive memory is set. It WILL NOT Change unless you flash it out and start all over again.

This procedure is vitally important for this installation as the install includes much larger fuel injectors and a lot more air being forced into the engine.

However I believe a lot of folks may find it useful on their won Jeeps.


Does it work?

Yes!

You best performance will happen when the Adaptive memory is set to the current conditions of your engine. I tested this on the Dyno.

My test was to dyno run my Jeep after flashing the PCM and resetting the adaptive memory as I described above, with 50 warm-up cycles over a 525-mile distance.

You see the results in the charts posted above.

The last dyno run I did was performing after I flashed the PCM Adaptive Memory while on the dynamometer. We then ran the test again, using in essence the Base Setting that come in the PCM from the factory. This resulted in a loss of 9 HP and 17 ft/lbs of torque.

While this was only one test it certainly is an indicator to me of the importance of having the ?Adaptive Memory? inside the PCM controlling the engine outputs based on the most current engine condition and not those set by the factory or those set in Adaptive Memory 83K miles ago.

I hope some folks will find this useful. I do believe it is a worthwhile task to do from time to time.

Frank

PS: We do not check for emissions here where I live, I would imagine if we did and if My Jeep failed I would be flashing the PCM Adaptive Memory and running the 50 warm-up cycles over 500 miles to reset things to optimum performance.
Frank, will this work for a 1999 or newer vehicle and would you recommend it for someone trying to track down what apparently is a non problem other than poor performance?

I have a situation with kendra's XJ in that it has no stored codes, nor activates the CEL but lets just say, it certainly doesn't run like the 4.0 in my TJ. I was thinking that a flash would allow the computer to re-learn and adapt to mine and kendra's driving style.
Thanx.
Reply With Quote
  #34  
Old 04-07-2004, 05:56 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Step 11 ? Relocate the MAP Sensor:

Disconnect the Battery. Always disconnect the Battery, even if you don?t think you need to!

The Manifold Absolute Pressure (MAP) Sensor is bolted to the side of the Throttle Body.

Go find your Throttle Body (Think clean out of the way place!) and bring it over to your shop bench.

See the rectangular shaped black boxy looking thing? That?s it.





Remove the two Torx Screws that hold it in place. You will need a T-25 bit.

Remove the ?L? shaped rubber fitting between the MAP sensor and the Throttle Body and remove the MAP Sensor.

Plug the vacuum port on the throttle body where the ?L? shaped rubber fitting was connected to, with the supplied 1/8-inch rubber plug and go put your throttle body back in that clean safe place again. You will need it later.

Pick a spot on or near the driver side inner wheel well to mount the MAP sensor.

I choose to make a small ?L? shaped bracket that allowed me to bolt the MAP sensor up to the studs holding the Brake Proportioning Valve Bracket on.

Here?s a picture.




I suppose you could use the Torx Bolts to mount the MAP sensor after relocating it but in truth I hate those things. I just dug through the bolt box and came up with some nice Stainless Steel Allen caps.

Here is a top view showing the MAP Sensor mounted to the proportioning valve bracket.





Before you mount the MAP sensor in it?s new home you may want to attach the 1/8-inch hose supplied with the kit to the port on the bottom of the MAP sensor. If you don?t do it now you will do it later using the Braille system like I did.


Find the ?-inch NPT thread X 1/8-inch hose barb fitting supplied with the kit.

You need to install this fitting in the vacuum port you left unplugged in the side of the intake manifold. Be sure to use some thread sealant or RTV on the threads.





Connect the other end of the 1/8-inch hose, running from the bottom of the MAP sensor, to the hose barb fitting you just installed in the manifold. Be sure to cut the hose with enough slack to allow for the engine room to torque over when you hit the skinny pedal..

NOTE: The MAP Sensor is the only vacuum operated device on your Jeep that should be plumbed to the intake manifold. All other vacuum devices will be plumbed later to the blower.

Also Note: If you decide to install an aftermarket Boost Gauge later you will plumb that into the intake manifold via one of the1/4-inch NPT threaded ports you plugged up earlier.


Your MAP sensor should now be relocated to it?s new home.

Go have a beer, you earned it. Heck you earned it just for reading this far. Relax, I?m almost done. We get to the good stuff soon!

Frank
Reply With Quote
  #35  
Old 04-07-2004, 05:57 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
I held an executive meeting with myself and the consensus was that it would be more fun to spend some of my limited time talking about the PCM, how it works (in regard to Ignition timing and Fuel Only. It does a lot more then what this will cover.), and how to make it do different things for you.

Here is a rather simple drawing of what goes on, under what conditions inside the PCM





The PCM receives Inputs from the sensors listed on the left.

Depending on WHICH Major Mode, Open Loop or Closed Loop, the engine is in, will determine what the PCM does with the sensor inputs.

Within the Major Modes (Open and Closed) there are sub-modes. I?m not going to retype them you can see them in the drawing.


IF the Engine is in any of the Open Loop Modes, the sensor input is collected by the PCM and run against a set of predetermined Memory Tables. Based on the values in these tables, the PCM will control the Ignition Timing AND Fuel Injector Bandwidth outputs.


IF the Engine is in one of the two CLOSED Loop Modes, the PCM will collect information from all of the sensors listed on the left AS WELL AS the Oxygen Sensor. The PCM will then calculate (computer will actually do some work) the correct Ignition Timing AND Fuel Injector Bandwidth.


It is that simple folks. Where it gets complex is when you want to override either the predetermined tables (Open Loop) or the Calculations (Closed Loop.)
Tuning A/F Ratios

One way is to take advantage of the Adaptive Learning of the PCM, as described before. Kinda like teaching an old dog new tricks after the super charger has been installed. However, this is only going to get you so far and appear to have limits to how far the tables will adapt.

Another way is to find some really smart kid who knows how to re-burn the memory tables and let him do it for you. Provided you know what data should be in the tables to meet your needs.

Note: I believe but do not know for fact that is this what some blower company?s call ?reprogramming the PCM.? They re-burn the memory tables with new values. I sincerely doubt they change the Calculation Algorithm being it only effects Closed Loop Modes, Idle and Cruise.


A third way is to artificially vary the Input signals till you get the Outputs (timing and bandwidth) to your liking!

There are two input sensors that have a significant effect on the outputs, these would be the MAP Sensor and the Intake Air Temperature Sensor.

Both of these sensors are nothing more the variable resistors. As there resistance varies, the voltage signal being sent to the PCM will vary.

So, if you want to change that voltage input signal to the PCM all you have to do is raise or lower the resistance at one or both of these sensors.

There are a few device out there that do this. A friend recently sent me a unit made by Speedtweaks. It uses the IAT sensor signal.

By increasing the resistance on this sensor you are telling the computer that the incoming air is colder then it is (more dense) , therefore the PCM will dump more gas through the injectors. (by increasing the Injectors Bandwidth, within the injector physical flow ability to inject fuel)

HKS sells a similar unit that will tweak the MAP Sensor and trick the PCM into thinking the pressure is greater or less then what it really is, and adjusts the injector bandwidth accordingly.

These devices do work, but within there design scope.

If you need to just tweak things a little bit this is the way to go. You are limited to a small range of change as contained in the predefined memory tables.

Also, when you do tweak things this way, you are tweaking things across the entire RPM range, EXACTLY the same way.

If it is a little tweak, no problem, things should be ok.

But if it is a big tweak I think you will find a lot of negatives associated with this. Too rich A/F at some RPM?s and too lean A/F at others. It?s an all or nothing type of thing.

Also, none of these devices will help in managing A/F ratios for Closed Loop Modes.

The more expensive units, like the A?Pexi Super AFC or HKS AFR-D enable you to adjust (add or remove) resistance at the MAP sensor in 500-RPM increments thereby changing the A/F ration in 500-RPM increments.

In other words, at every 500-RPM you an opportunity to richen or lean out you?re a/F ratio.

Both units can and do manage the Air Fuel Ratios during Closed Loop Modes as well. This is particularly important during Idle when you have rather large injectors installed but no boost being blown into the cylinders.


Bottom line, the very first thing I will do if I find I have an A/F Ratio problem is to make sure all my sensors are working in peak order. (Read that replace them)

If I find my A/F ratio is across the board, a little lean or a little rich I will tune that out using one of the simple resistive units on the AIT or MAP sensor.

If I find I am rich or lean at different times, I will go with a piggyback A/F Controller. Probably the A?Pexi or maybe the HKS if I can learn more about it.

I hope this has been helpful to some. Please realize I am not an expert at this but I am more then a little knowledgeable on the topic.

The drawing was a simplification of the PCM in this regard. While the inputs, outputs and modes of operation are factually correct, there are many others that I have not shown to keep this simple.


Now it?s back to the salt mines to finish up the installation instructions.

Have a great day folks.

Frank
Reply With Quote
  #36  
Old 04-08-2004, 10:03 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Step 12 ? Install the Blower / Intercooler Assembly: FINALLY!!!!

By the time you are done with this task you and everyone else will be able to ?SEE? what you have been doing all this time.

Disconnect the Battery

Remove the Duck Tape you put over the Intake Manifold Throttle Body hole.

Using the original Throttle Body Gasket and the five (5) supplied flat top Allen bolts, mount the ?Intercooler to Intake Manifold Adaptor Plate? to the Intake Manifold.




Please note, there are two ways to mount this plate, upside down, and the right way. Don?t ask how I know, just make sure the side with the ?O?-ring grove cut around the intake manifold opening if facing up and you will be ok.

Also as you can see there is an oval shaped hole cut in the adapter. This is to allow clearance of the manifold casting nipple and vacuum port plug.


Be sure to use Medium Strength Loctite (the blue stuff) on these screws. You will need a 5/32-inch Allen wrench. Torque these bolts down to 108 in/lbs.


Remove the Serpentine Belt

You will need a 15mm wrench to loosen the Idler Pulley




Use the same wrench to loosen the adjusting screw behind the idler gear.

Once you have the belt loose it will come right off.



Install the IAT Sensor

The Intake Air Temperature Sensor needs to be installed on the bottom of the intercooler before you install the blower / intercooler assembly on the intake manifold. You will need a ?-inch wrench.

There are two ways to install the IAT Sensor, depending on model year of your Jeep.

Turn the blower / intercooler assembly over and take a look at the bottom of the intercooler.




You will find one open hole and another with a plug in it.

The threaded hole that is cut Straight, at a 90 degree angle to the intercooler, as you would expect, should receive the IAT senor if your Jeep is a 2000 model year or OLDER.

The threaded hole which is cut on an Angle, (about 15 degrees) should be used to install the IAT Sensor if your Jeep is a 2001 Model year or NEWER.

Be sure to use thread sealant or RTV on the threads of the IAT Sensor and torque it down to 20 ft/lbs.

Make sure the hole you don?t use is plugged and sealed with thread compound.

My Jeep is a 97, so you see in the picture above the IAT Sensor went in the straight cut threaded hole in the bottom of the intercooler.

Why two holes? This is to allow room for the IAT Sensor to clear the changes made by Jeep in the intake manifold design in the later years.



Mount the Blower / Intercooler assembly

Find the rather large ?O?-ring in your package and place it in the machined grove in the Intercooler to Intake Manifold Adaptor Plate.





Grab some shop towels and some tape and wrap them around the Radiator Support rod on the drivers side. This is not only to protect from scratches but also to aid you in placing the Blower / Intercooler in place. Trust me, its like doing upper arm curls and the rags help you from killing your arms.






Get a good grip of the Blower / Intercooler assembly and gently lower it down on top of the intake manifold adaptor plate.

Important Do not forget the IAT Sensor is hanging down below the intercooler. When you put this assembly down do not hit it.

Also, do not slide the assembly around. If you do you could damage the ?O?-ring. You want to curl it right down on the manifold adaptor. If you don?t get it right the first time, PICK IT UP and relocate it. Do not Slide it around!

End of Important!







Once you have it in place and the bolt holes line up, bolt the Blower / Intercooler assembly to the manifold adaptor plate using the 4 supplied Allen Bolts.

You will need a 6 mm Allen wrench.


Blower Nose Support

Attached the Blower Nose Support to the Power Steering Pump mounting bolts.

There are three P/S Pump Mounting bolts one located at about 1 o?clock, another at 10 o?clock and the third at about 7 o?clock.

Remove the first two bolts entirely.

DO NOT remove the bolt at 7 O?clock, but rather loosen it and back it out about ?-inch.

If you remove them all, the P/S Pump falls down and goes Boom! (Don?t ask.)

To get to these bolts you will need a ?-inch deep well socket. You will access these bolts through a hole in the Power Steering Pump Pulley.

Like this.






Once you have removed the top two bolts and back the bolt located at around 7 O?clock out about a ?-inch, you need to loosen the Allen Bolt used to clamp the Blower Nose to the Bracket. Use a 5 mm Allen Wrench.

When you do this you will be able to swing the bracket down behind the Power Steering Pulley. The bracket is slotted to slide right behind the bolt you backed out.

Once you have it in place, install the two bolts you removed and line things up, then tightens these bolts down to 25 ft/lbs.

Tighten the Allen Bolt to clamp the bracket to the Blower Nose with the 5mm Allen Wrench.

NOTE: If you have a 2001 or NEWER TJ you need to swap the stock Idler Pulley with the Idler pulley that came installed on the Blower Support Bracket. Take them both off and relocate one in place of the other.

NOTE2: If you have a 1998 or NEWER TJ you may need to grind a very small amount of material from the bottom of the thermostat housing. Do this carefully as the housing is very thin.

Why you ask? I have no clue. Mine is a 1997!

Please read that; I don?t know what I am talking about here but it is in the instructions that Avenger sent so I figure I would put the note here

End of Note 2



Go call someone so they can admire your work. When they say, ?Finally!?; hit them with something, soft! Like a wrench!

The Blower / Intercooler Assembly is now installed.





On to the next step.
Reply With Quote
  #37  
Old 04-09-2004, 05:48 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Hi Folks,

If at times it seems like I am putting a post up that doesn?t flow with the previous it is because I am maintaining this subject on two forums. Sometime I have something that I believe everyone may find of some value so I am just posting it in both places. This is one of those times.


MAP Sensor Testing at Throttle Body

I did a little testing today to see if I could notice any difference in performance when the MAP sensor is plumbed to the Throttle Body, vs. the side port on the intake manifold.

According to the old and calloused seat of my pants I could not tell any difference at all.

I switched this back and forth a few times trying to get some difference. If there is a difference I can?t feel it. I will do this again when I get it on the Dyno, probably next week.


More Observations:

The more I drive my Jeep the better it seems to be performing. I have no hesitation of any kind (unless I am in a really exaggerated ?lugging? gear and I step on the skinny pedal.

This leads me to believe that the PCM flush and adaptive learning appears to be working. I do however still believe I am running on the rich side for the A/F ratio.

Do any of you ever smell raw gas at Wide Open Throttle? If so, do you have any idea where it is coming from?



Basic MAP Sensor Operations

While sitting at the Waffle House this morning enjoying my breakfast I penciled out the basic operations the MAP Sensor in graphic form and how it can be ?adjusted? artificially to open up or close down the bandwidth of the Fuel Injectors.

Here are two computers drawing in my attempt to explain my understanding of things.










The A/F Controllers we talked about earlier, like the HKS and A?Pexi units can and do adjust both Resistance and Input Signal Voltage.

But there are other ways of doing it to.

Resistance is real easy, and so is increasing the Input Signal voltage. A lot of this info has been around for years and published in lots of places.

I am going to post several links here to a few articles describing how to build a simple circuit to Increase the MAP Sensor Input Voltage.

PLEASE PLEASE PLEASE Do Not Do this until I have a chance to explain some of the down sides and risks to these designs that I know of. I simply do not have the time at this moment but do want to get the info out so that these things can be read and understood by those who might be interested.

Here?s some links

http://www.angelfire.com/my/fan/MAP_adjuster.html

http://www.rightcoastcrawler.com/bil...EMAPSENSOR.HTM

http://www.jeepbarracks.com/modules....article&sid=18

All three of these articles basically describe the same easy to build circuit designed to ?Increase? the input voltage (Above the normal +5 volt) t the MAP sensor.

Advertised has I have built it and used it on other vehicles. However I have designed in a safeguard and also was willing to run some risk in using it.

I apologize I don?t have more time to explain the risk but I will shortly.


Scott, You are right, that 5 volts is a one bar system. The circuits above are how they add more bars artificially to tune the injectors to the airflow and the PCM


Frank
Reply With Quote
  #38  
Old 04-09-2004, 07:16 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Step 13 ? There is no Step 13!!!

Not that I am superstitious, but I mean why push it. With my luck my A/F ratio would go so lean I?d blow my engine up.

So??.

On to step??..


Step 14 ? Complete the Intercooler Plumbing

If you followed my order of installation you should have the Intercooler Radiator, Water Pump and two Hoses in place.

The hose running form the bottom port of the intercooler radiator should be attached to the center (inlet) port of the pump. If you haven?t done this earlier now would be a good time to do it.

You will have a 90-degree bend hose in the package. Find it and fit this hose to the back of the intercooler and the side (exhaust) port of the coolant pump.





Run a short length of hose from the Outlet Port on the Front of the Intercooler over to the radiator Support Rod on the driver side. Connect this hose, to the hose connected to the upper port of the Intercooler radiator using the supplied ?T? connector.

Tight down all your hose clamps.

Attach? the Filler ?T? to the Radiator Support Rod with a couple of cable ties. This ?T? fitting needs to be the highest stop in the intercooler system.





Fill the Intercooler

You are going to need a 50/50 mixture of coolant and water to fill the system. Just short of 1 gallon.

I used premixed stuff from Wal-mart, but with a twist.

Being my engine uses the ?green stuff? I purchased the ?Yellow Stuff? to use in the intercooler.

Why?

Well if I ever have to trouble shoot a leak my evidence will be color coded for me at the system level!

Filling the intercooler is a time consuming task. The instructions tell you that, but it still took me over 2 hours to make sure I managed to get all the air out of the system.

Connect the Battery and Connect the Coolant Pump to its power source.

Fill the system with the coolant through the ?T? fitting.





When you have it filled (you really don?t) turn the pump on!

(I did this from under the hood, with the ignition key on, by touching the fuse to the contacts of the fuse holder I installed for the pump..


Do this for only a few seconds.

What you will find is you now have a lot more room to put more coolant in!.

Fill it up again and turn the pump on for a second or two.

And go through this cycle till you can?t get any more in.

Trust me, you do not have all the air out of the system yet.

Leaving the cap off the ?T? fitting, turn the pump on and let it circulate for a while.

Listen while you do. When the air pockets hit the veins in the pump you will hear a very distinctive sound.

Note: Running the pump with the ?T? fitting open is a messy proposition. Coolant will indeed bubble out so have some shop rags handy.

You are just going to have to cycle the pump on and off like this till you work all the air out.


Scott was kind enough to send me a picture of an overflow tank he installed to eliminate this problem.

Here it is.




Basically the coolant flows into the over flow tank, and then is sucked out the bottom by the pump.

Any air in the coolant remains in the overflow tank. Nice set up. If I ever find I have a problem with air in the system, I certainly will investigate doing this the same as Scott has.

For now all is fine, it was painfully slow but I believe I managed to get it all out.


Install the Serpentine Belt

Follow the factory routing diagram under your hood. When the belt gets to the power steering pump it is routed over the blower pulley and then under the additional idler pulley.

Don?t worry if that isn?t clear, the instruction come with an illustration for the Model Year of your TJ. I do believe there are at least 3 different belt routing based on year.


Step 14 is done, only a few more little ones and you get to fire it up.

Frank
Reply With Quote
  #39  
Old 04-10-2004, 05:39 AM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Quote:
Originally posted by Robert J. Yates
Frank, will this work for a 1999 or newer vehicle and would you recommend it for someone trying to track down what apparently is a non problem other than poor performance?

I have a situation with kendra's XJ in that it has no stored codes, nor activates the CEL but lets just say, it certainly doesn't run like the 4.0 in my TJ. I was thinking that a flash would allow the computer to re-learn and adapt to mine and kendra's driving style.
Thanx.
Hi Robert,

My Apologies I did not see your question until just now.

Old age setting in.

I think re-flashing the PCM in Kendra Jeep is certainly worth a shot. I do believe the fast learn procedure will work on it.

When I did this the first time I had a very noticeable drop in performance. It seemed sluggish until I managed to get a few warm up cool down cycles on it. Then performance improved. In my case as in back to normal.

I have received over a dozen PM's from folks who have had various engine performance issue with no codes, such as sluggish. Most have said they notice an improvement after they did the flash/learn mode procedure. Maybe this was perception on there parts, maybe not I don't really know.

Give it a shot.

Before you do I'd suggest cleaning the coolant and Intake Air Temp Sensors on Kendra's Jeep. Both of these can and do have a major effect (like other things) on how the Jeep runs.


Pull the Coolant Temperature Sensor. It is located in the thermostat housing and clean it. You will probably find a small scale buildup on it. Remove it with some rubbing compound. This scale will insulate the sensor and cause it to send signals to the PCM that the engine is cooler then it really is. I have seen this cleaning alone solve more then a few "pinging" problems.

Also pull the Air Temperature Sensor from the top/rear of the intake manifold. When you get it out you will see a white cage like housing. Inside the housing is a thermostat. In all likelihood it will be covered with carbon.

Do not take this sensor apart. Rather run down to radio Shack or Ace Hardware and pick up a spray can of "Electric Motor Cleaner". Please do not use anything else, you could damage the sensor.

Spray it till it is clean.

Also, have you ever taken the engine above 3,500 RPM?

Now might be a good time. At 3500 RPM the intake and exhaust valves begin to rotate. The 4.0 engine is designed to do this to help shed carbon build up. I wouldn't be afraid to do this, 3500 isn't high at all for this engine.

Let me know if any of this makes any difference for Kendra.

Frank
Reply With Quote
  #40  
Old 04-10-2004, 07:56 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Step 15 ? Install the Pressurized Oiling System:

Here you are going to tap into the engine oil pressure system at the Oil Pressure Sending Unit and install a ?T? fitting to supply pressurized oil to the Blower bearings. You will also be installing the low-pressure oil return line to the fitting in the oil pan you installed earlier.


Disconnect the battery.


Install the ?T? Fitting and High-pressure Oil Hose

Find the Oil Pressure Sending Unit on the passenger side of the engine block. It is right above the oil filter.

Unplug it and remove it. You will need a 1 & 1/16-inch wrench.

Install the supplied Brass T fitting and reinstall the Pressure Sending Unit. You will need a 9/16-inch wrench for the T fitting. Also be sure to use thread sealant or RTV sealent.

Plug the Pressure Sending Unit back in.

Attach the high-pressure oil hose (gray) to the top of the T fitting you just installed. Use Thread sealant and a 7/16-inch wrench.





NOTE: Before you install the High-pressure hose to the Blower you must make sure it is absolutely clean inside. Please be sure to perform the next procedure, it is important!

Find the Power Distribution Center (PDC)on the passenger side inner fender and remove the cover. Look at the underside of the cover to identify the location of the Automatic Shut Down (ASD) Relay.





Pull this relay out. This will disable the fuel pump, injectors and ignition system.

Find a friend to help you for a few minutes. Also find a ?catch can?.

Reconnect the Battery.

What you need to do is hold the end of the high-pressure oil hose in a ?catch can? while someone cranks the engine over. You want oil to start to flow out of the high-pressure oil line you just installed. This will ensure it is perfectly clean inside.

Once you get 4 or 5 ounces of oil out you are set.

Stop cranking and disconnect the battery again..

Plug your ASD Relay back in place and out the cover back on the PDC.

Top off engine with clean oil as needed.

Now route and attach the high-pressure hose to the open (top) port on the passenger side, front of the Blower, like this.






Install the Low-pressure Oil Return Hose

Attach the 3/8-inch hose between the brass hose barb fitting on the driver side of the blower, toward the front (bottom). There is a 90-degree brass hose barb fitting already installed there.





Attach the other end of the low-pressure oil return line to the hose barb fitting you installed in the oil pan in an earlier step.

Be sure to trim this hose to the correct length. If you leave it to long there is a possibility that it will hit the steering shaft.

Using supplied hose clamps tighten these down.


The Pressurized Oil System is now installed to the Blower.
Reply With Quote
  #41  
Old 04-11-2004, 08:05 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Step 16 ? Install the Throttle Body:

Disconnect the battery if you haven?t already.


Grind the Casting Tab

Before you can install the Throttle Body on the Blower Intake Air Horn you need to grind down a small square aluminum casting tab on the base of the Throttle Body so that it is flat with the base.

Using Duck Tape, cover the top and bottom of the Throttle body. While you are at it cover up all the sensor too. No need to get a metal shaving someplace it doesn?t belong.

Put a shop towel around the Throttle Body and ?LIGHTLY? clamp it in a vise, bottom side up.

Start grinding.

Please note this is aluminum and it will grind off really fast.

I am sorry but I do not have any pictures of this either before or after grinding. They are simply unintelligible.

While my Throttle Body was very clean on the inside, I found I could not bring myself to mount its oxidized body on the pretty new blower the way it looked. And being I already had it all taped up and protected, I decided to put it in the bead blasting cabinet for a quick go around.

Nice! Now it looks pretty too!

Remove all the duck tape from the Throttle Body.

Double-check everything for dirt or metal filings. Use compressed air to blow everything out.

Find the package that contains the rubber vacuum plugs. If you haven?t already done so, plug the vacuum port on the side of the Throttle body where the MAP sensor used to live.


Mount the Throttle Body

The instructions tell you to use a thin film of sensor save silicon sealant between the Throttle Body and the Blower intake air horn.

I didn?t like this folks. So I ran out to NAPA and picked up another Throttle Body Gasket. This was the one and only time I had to run to the store for anything I felt was needed to complete this installation that did not come with the kit. And in truth it was my choice.

I would think it wouldn?t be a big deal to include a Throttle Body gasket in the kit. But like I said, it wasn?t a big deal to go get either. (Hint Hint Jack!)

Bolt the Throttle Body (with gasket or sealant) to the Blower Air Intake Horn using the four 5mm Allen Cap blots provided.

Torque these down to 108 in/lbs.

Mount the Jeep?s original Throttle Cable Bracket to the Blower side bracket using two 5 mm Allen Cap bolts.

Attach the Throttle Cable to the Throttle Body and attach the Throttle Return Spring.

Here a picture.





See that pretty 84K mile Throttle Body?!

Also note, the second cable you see going to the Throttle Body via the Bracket is for the hand throttle I have installed.


This task is complete, on to the next. We are almost done.

Frank
Reply With Quote
  #42  
Old 04-12-2004, 09:07 AM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Step 18 ? Install the Vacuum Lines:

This Super Charger kit comes with a rather large assortment of Vacuum hoses, fittings and T fittings, more then enough to plumb your entire vacuum system.


Attach the Vacuum Brake Booster hose to the 90-degree brass fitting on the back of the Blower. This is the only vacuum line that should be attached to this fitting.

If you haven?t already done so, attach the vacuum hose from the MAP Sensor to the port on the side of the intake manifold. This is the only vacuum device that should be connected here.


All other vacuum devices need to be connected to the straight Brass Hose Barb fitting on the back of the blower. This Includes the rear valve cover breather, evaporative canister, and any heat control vacuum hoses your Jeep may have.

Use the adaptors fitting, T?s and hoses.

Here is a picture in which I think you can see some of the vacuum hoses and t-fitting I used.






Step 19 ? Modify Filtered Air System:

The kit comes with a flexible hose that you will need to employ to connect the Throttle Body to the Air Filter System you are going to use.

I used my relocated stock air box as it is attached to my Snorkel.

How you go about doing this really will depend on your Jeep. The fact that the Throttle Body is located in a completely new position in the engine compartments means you will have to work your filtered air system to one degree or another, using the flex hose to connect the two.


You will also need to tie the Blower Nose vent into the Front Crank Case Breather hose, which connect the valve cover to the air intake system

To do this the kit comes with the required hoses and a T fitting that is ?-inch x ?-inch x 3/8-inches.

Here is what my installation looks like. I think you can see clearly the flex hose as I used it and the Blower Vent hose plumed into the crank case breather with the ?T?.





This is the end of all mechanical installation tasks. There are only a few more things to do. Flash the PCM into fast learn mode, double check your work and fire it up!



Step 20 ? Last Step - Put PCM in Flash Mode:




PCM Fast Learn Mode

The Jeep?s PCM performs several functions controlling Air Fuel ratios via Injector Bandwidth and Ignition Timing.

These ?outputs? are controlled using the ?inputs? received from all the sensors and then comparing these reading against a set of data tables burned into the PCM.

These ?memory tables? are the brains that keep the engine running at low emissions and peak economy across the RPM band during closed loop mode.

These memory tables can and do change. They are ?adaptive?, based on sensor readings, driving habits, engine performance and sensor tolerances.

Over time, the PCM Memory Tables become tuned to your engine.

This procedure first came to me from the folks at Avenger. I then verified it with a phone call to a Chrysler Engineer who had called me a year or so ago to ask about my experiences with a certain part on my TJ. I figured he owned me a favor. He had to check up on this for me. He called me back a week later and did indeed verify this procedure and what it does.

To the best of my knowledge it isn?t documented in any of the FSM.



Forced Flash

This very simple procedure will Erase the ?Adaptive Memory? stored inside the TJ PCM and allow a new ?Adaptive Memory? to be developed.

After performing this procedure the PCM will re-learn and store into Adaptive Memory your engines performance characteristics.

Please perform these steps exactly as they are written, in the order they are written. This will cause the adaptive memory in the PCM to be erased and cause the PCM to go into Fast Learn Mode adaptive mode.


  • Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.
    Reconnect the Battery Cable
    Turn Ignition Switch to the ?On? position but DO NOT start the engine
    Turn Headlight ?On?
    Turn Headlights ?Off?
    Turn Ignition Key ?Off?

The PCM Adaptive memory has now been flashed, or erased from the PCM.

When you start the engine it will be running off a set of pre-programmed tables that come with the PCM from the factory.

When you get the engine up to operating temperature the PCM will start to collect data for the ?Adaptive Memory?.

The PCM will collect data for Adaptive Memory for the first 50 Warm-up Cycles.


Warm-up Cycle

A warm-up cycle happens when all of the following conditions exist.

Engine is running
A raise of 40F in engine temperature must occur ABOVE the engine temperature at start-up
Engine Coolant Temp must reach at least 160 F.


Once your engine has gone through 50 warm-up cycles in at least a 500-mile distance the PCM adaptive memory is set. It WILL NOT Change unless you flash it out and start all over again.

This procedure is vitally important for this installation as the install includes much larger fuel injectors and a lot more air being forced into the engine.

However I believe a lot of folks may find it useful on their won Jeeps.



Double Check Everything

Check the hoses, fuel lines, coolant level, engine oil, all bolts, and belt tension, ECT?

When you are done,

Start the engine and let it idle for 5 minutes, then take it for a ride.

Power should progressively improve as you go through the a higher number of warm up cycles.

DONE! FINALLY!!!

Sorry it has taken me so long.

Frank
Reply With Quote
  #43  
Old 04-13-2004, 08:35 AM
JLemieux JLemieux is offline
Registered User
 
Join Date: Sep 2003
Location: Corona, Ca.
Posts: 156
I must take issue with all of the "Forced flashing" of the PCM that seems to be going on in this post.
For the super charger install, this is exactly what needs to be done. For all of the others doing this to their non-supercharged Jeeps, you are only making your engines run worse until the PCM has adapted the the fuel right back to where it was before you "Force flashed".
I think the piece of information that has been missed here is that adaptive learning is an ongoing process. It changes to current conditions of your engine.
If you have a cracked vacuum hose and a small vacuum leak, the O2 sensors see a short term lean condition and trims the fuel a little bit richer. This is referred to as "Short term fuel trim" or STFT. Since this cracked vacuum hose is not going to fix itself, this lean condition continues to exist and the PCM sees the O2 sensors still lean so it changes the "adaptive memory" to a richer mixture to compensate for the long term lean condition. This is call "Long term fuel trim" or LTFT.
The adaptation is different for every throttle position and load combination and is constatly being updated for current engine wear, sensor condition and any other item that will change the air/fuel ratio from where the PCM whats to see it.
So let's say you typed a 10,000 word essay on you word processor and didn't save it. On word 9,999 someone resets your computer (Forced flash). You get to type it all over again, but in the end you still have the same thing.
__________________
Quality is like buying oats. If you want clean, fresh oats you must pay a fair price. If you want oats that have already been through the horse, those are a little cheaper.
Reply With Quote
  #44  
Old 04-13-2004, 09:43 AM
Robert J. Yates Robert J. Yates is offline
Registered User
 
Join Date: May 2001
Location: planet earth
Posts: 6,212
Quote:
Originally posted by JLemieux
I must take issue with all of the "Forced flashing" of the PCM that seems to be going on in this post.
For the super charger install, this is exactly what needs to be done. For all of the others doing this to their non-supercharged Jeeps, you are only making your engines run worse until the PCM has adapted the the fuel right back to where it was before you "Force flashed".
Not that I disagree with that John but what does one do when neither a code is thrown or stored yet the Jeep runs like crap? How do you propose to find the problem then? This is a 2000 XJ - service is up to date.
Reply With Quote
  #45  
Old 04-13-2004, 05:25 PM
JLemieux JLemieux is offline
Registered User
 
Join Date: Sep 2003
Location: Corona, Ca.
Posts: 156
Quote:
Originally posted by Robert J. Yates
Not that I disagree with that John but what does one do when neither a code is thrown or stored yet the Jeep runs like crap? How do you propose to find the problem then? This is a 2000 XJ - service is up to date.

Hi Robert,
There are many things that can cause the engine to run badly and not set a code. Does this XJ have the distributorless ignition?
If so, this is a waste spark type system. This means that one coil fire two spark plugs at the same time. The spark goes down through the top of one plug and returns to the coil through another plug from the bottom up. The second plug actually fires backwards up the spark plug. So when the two cylinders fire at the same time, one is on the compression stroke and the other is on the exhaust stroke. That is why the second plug doesn't affect anything when it fires, thus the spark is "Wasted"
What this means to you, is if you have a coil or a spark plug going bad it can cause a misfire on 2 cylinders resulting in a very badly running engine.
Unless this misfire happens more than 20% of the time within 1000 revolutions the PCM will not set a code. This is an over simplified explaination of the misfire monitor, but that might give you an idea of what could happen.
Another possibility could be a fuel problem like a leaking fuel injector. The PCM will not set a code, but this will show up in the Long Term Fuel Trim as a negative value. This means the computer is taking away fuel to compensate for the extra fuel it is getting from the leaking injector. (Adaptive learning)
You will need a scan tool to see this data.
Bottom line is that the computer cannot see mechanical problems. It can only react to them. This is why Auto Zone got sued for selling an O2 sensor to everyone that had an O2 sensor code in the computer. Most of the time, an O2 sensor code is the result of some other problem but it is the only thing that the computer can see.
__________________
Quality is like buying oats. If you want clean, fresh oats you must pay a fair price. If you want oats that have already been through the horse, those are a little cheaper.
Reply With Quote
  #46  
Old 04-13-2004, 06:58 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Hi Folks,

My plan to put the Jeep on the Dyno tomorrow has to be postponed due to a personal situation out of my control.

I will get this done early next week and post the results as soon as I can scan them in.

Thanks for understanding,

Frank
Reply With Quote
  #47  
Old 04-13-2004, 07:56 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Quote:
Originally posted by JLemieux
I must take issue with all of the "Forced flashing" of the PCM that seems to be going on in this post.
For the super charger install, this is exactly what needs to be done. For all of the others doing this to their non-supercharged Jeeps, you are only making your engines run worse until the PCM has adapted the the fuel right back to where it was before you "Force flashed".
I think the piece of information that has been missed here is that adaptive learning is an ongoing process. It changes to current conditions of your engine.
If you have a cracked vacuum hose and a small vacuum leak, the O2 sensors see a short term lean condition and trims the fuel a little bit richer. This is referred to as "Short term fuel trim" or STFT. Since this cracked vacuum hose is not going to fix itself, this lean condition continues to exist and the PCM sees the O2 sensors still lean so it changes the "adaptive memory" to a richer mixture to compensate for the long term lean condition. This is call "Long term fuel trim" or LTFT.
The adaptation is different for every throttle position and load combination and is constatly being updated for current engine wear, sensor condition and any other item that will change the air/fuel ratio from where the PCM whats to see it.
So let's say you typed a 10,000 word essay on you word processor and didn't save it. On word 9,999 someone resets your computer (Forced flash). You get to type it all over again, but in the end you still have the same thing.
Hi John,

Thanks for the post!

I think we are both saying the same things but with a slightly different understanding.

The "Adaptive Memory" is set in the first 50 warm-up cycles that occur in anything greater then 500 miles of driving and it then DOES NOT CHANGE unless you force flush the PCM using this procedure. Source = Project Manager Jeep PCM Engineering

Please understand I verified this 4 times with the this gentleman to make sure I understood this correctly. It is also what Avenger was telling me and that is what made me investigate. I have since validated it through a third source who dyno-tunes and reprograms most PCM's including the type in our Jeeps.


The Adaptive Memory uses as it's starting point the Volumetric Efficiency Tables which are burned into the PCM. From there it reads sensor signals and adjusts the VET over the 50 warm-up cycles to the condition of the engine.

Being the Volumetric Efficiency Tables come into play, only during Closed Loop Modes, the O2 sensor does not enter the picture at all.


I am in full agreement and understand in your description of the "Short Term" and "Long Term" Fuel Trim changes.

These changes are made on the fly and continuously based on the voltage (0.1 to 1.2v) sent from the O2 Sensor to the PCM indicating an A/F ratio condition, (it's actually Oxygen Content in gasses) BUT only in Closed Loop Mode which is at Idle and Cruise Only.

The O2 Sensor signal is ignored at all other times. Source = FSM and Project Manager Jeep PCM Engineering.

Also an import fact the PCM will not go into closed loop mode until the Coolant Temp is above 160 F., further restricting when Short and Long Term Trim occur.


Here is a better picture of what is going on at a high level between the Sensors, PCM and PCM outputs concerning A/F and Timing.





The MAP and IAT sensors send Air Pressure and Air Temperature to the PCM. With that info, the PCM Calculates the Air Weight using the "Perfect Gas/Air Law" (Why? cause Air Fuel Ratio are based on weight, the weight of the Air and the Fuel).


Once the weight is determined, the PCM decided how much fuel (in weight) is needed. This comes from the Volumetric Efficiency Tables ("Adaptive Memory") when in Open Loop Mode,


OR


is calculated when in Closed Loop Mode with the help of the O2 Sensor Signal and Coolant Temp Signal.

Both "short and long term fuel trim" occurs here in Closed Loop Mode ONLY.


I am not sure I have explained that clearly, my apologies if I haven't. It has been a long day.

Have a great night. I'll be out of pocket till Sunday.

Frank

PS: I do not know what this is worth yet long term, but I have received emails and PM's from several dozen Jeeper's who have done this procedure. Every one claiming a major improment in perfromance. Guess we will have to wait and see it it holds up.
Reply With Quote
  #48  
Old 04-13-2004, 09:15 PM
JLemieux JLemieux is offline
Registered User
 
Join Date: Sep 2003
Location: Corona, Ca.
Posts: 156
Frank,
First I need to say that all my information comes from my training in emissions and computer controls. This information comes from instructors that are not experts on Jeeps specifically but more on computer controls in general. So if there is a Jeep specific control at work here I really want to understand. In all my travels I have not heard of this adaptive memory that stops adapting after 50 warm up cycles. Not to say it can't exist, only that I have never heard it discussed.
I'm still not sure we are not talking about the same thing and I am certainly not discounting any of your research (we all know how little effort you put into that).
But you do have one bit of information I believe is wrong.
That is that the LTFT does come into play in open loop (although the O2 is ignored). If this "adaptive memory" was not taken into acount in open loop than any changes made by it would be negated by the VET you speak of and that could lead to extremely high emissions in open loop. That is a big no no to the smog gods. That is why I am leaning towards the thought that your VET and my adaptive learing are one and the same. Where we differ is that mine is continuous and yours ends after 50 warm ups.
I will continue to to look into this on my end in hope of learning something new. But I do stand on my point that the adaptive memory of which I speak of will be the same after the force flash is performed.
__________________
Quality is like buying oats. If you want clean, fresh oats you must pay a fair price. If you want oats that have already been through the horse, those are a little cheaper.
Reply With Quote
  #49  
Old 04-20-2004, 02:57 AM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Good Morning John,

Sorry for the delay in replying. I have been out of town for a few days. I have a special guest visiting with us this week and won't be able to get to far into this until the weekend.

I have a call into my friend to go over again his efforts to get me up to speed on all of this. Like you I am wanting to understand how this actually works.

The 50 warm-up cycles and then Stop was and is completely new to me as well. Yet that said, the source of that info comes from three different places, independent of one another, including the manufacturer. But obviously I am not understanding something, or not explaining something correctly.

Before I started this project I knew little about the actual PCM block functions. Now I may know even LESS!

Bare with me, I will see what I can find out with some clarity on this and get it posted for discussion as soon as I can.

Have a great day my freind,

Frank
Reply With Quote
  #50  
Old 04-20-2004, 10:27 AM
Robert J. Yates Robert J. Yates is offline
Registered User
 
Join Date: May 2001
Location: planet earth
Posts: 6,212
John,
The XJ does in fact have the distributorless ignition. I'll have a go at it from that angle and see what happens. I do know there is no injector leak - been under the hood with a fine tooth comb so as to eliminate any of the obvious stuff. Thanx.
Reply With Quote
  #51  
Old 04-20-2004, 09:11 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Hi John,

I have a little more information to share on this.


As I suspected, you and I are basically saying the same things here, only I am confusing things in my explanation. But here are the things that I know, and I consider being statements of fact, along with the source of the facts.

The PCM controls a lot of things, such as Fuel and Ignition System, and Emissions Monitoring, and a whole host of other functions.

The two we are interested in, F&I and E are affected by which of two major ?modes? of operations, Open Loop and Closed Loop the engine is in. (FSM)

During Open Loop Modes Emission and F&I are managed exclusively via a set of Open Loop VET Tables which are certified by the Manufactures to produce acceptable levels of emissions to the Smog God?s. (FSM & Chrysler Engineer)

These tables and any adjustments to these tables are a part of this certification.

The ?Adaptive Memory? or PCM Flush/Flash that I mention does indeed happen exactly as I have described it earlier in this post. The first 50 warm up cycles and it is set forever. This process is used, and certified by DC with the Smog God?s to account for the rather large sensor variances that exist between any two sensors, and how all the Jeep sensors work together as a ?System? to maintain the Certified Open Loop VET Tables. (Chrysler Engineer)

Sensor variances can be as much as 30% as published in the FSM. (Chrysler Engineer)

Given one sensor can be 30% less then optimum, and another could read 30% more then optimum, this ?system calibration is needed. This is exactly how the DC engineer explained it to me today. This Sensor System Calibration is a part of the Open Loop Emission Certification that DC has to have to manage Open Loop Emissions to the Smog God?s satisfaction. (Chrysler Engineer)

In addition to this I asked for and received a clarification on the O2 sensors and short and long term fuel trim.

Here is is:

Open Loop modes are managed ONLY by the tables after receiving input from all the sensors (ACCEPT the O2 sensors). There is NO Short or Long Term Fuel Trim performed during Open Loop Mode. (Chrysler Engineer)

Short and Long Term Fuel Trim happen only in Closed Loop Mode. (Chrysler Engineer)

In this mode the O2 sensors are the major player in determining the correct A/F ratio and lowering emissions. There is indeed a PCM table maintained for Closed Loop operations for Long Term Fuel Trim. This table is indeed adaptive and changes over time to help manage the lowest emissions, but only in Closed Loop Mode. (Chrysler Engineer)

This is I guess where the confusing has come from.

This is indeed an ?adaptive memory table?, over time to manage the injector bandwidth. However it is a different table then the Open Loop 50 cycle table I mentioned before.

That said I have another piece of the puzzle too. The ?Official Chrysler Procedure? to flash the PCM into fast learn mode does indeed ?Clean Out? BOTH the ?Adaptive memory? (Used during open loop modes) I mention at the start, AND the Long Term Fuel Trim Memory (Used for the closed loop mode.) (Chrysler Engineer)

Also this Long Term Fuel Trim Memory, just as you described, does indeed continue to evolve to address changing conditions over the life of the vehicle.

Bottom line as I understand it, there are two major memories written to the PCM.

The Closed Loop 50 cycle sensor system calibration, as certified by Chrysler to the Smog Gods and approved, (This is what I was referencing without fully understanding it.) (Chrysler Engineer)

And

The adaptive Long Term Fuel Trim memory,used ONLY during Closed Loop Modes and continuously adjusted. (Chrysler Engineer)

I also found out that this Long Term Fuel Trim memory is adjust by using values recorded in the last 40 (forty) warm up cycles. When cycle 41 is recorded, cycle 1 is dropped from the calculations. (Chrysler Engineer)

Some other info I managed to get is that all 97 or newer Dodge trucks (gas powered) use the same basic PCM and PCM emissions and fuel management system as the Jeep. The flash flush procedure I described will indeed work for them as well. (Chrysler Engineer)

It will not work on 95 or older Jeeps of Dodge Trucks.

Also something else new:

The Jeep PCM monitors the sensors, over time and compares the values received against the values set in the Open Loop Sensor System calibration (50 cycles) not only for Functionality (Are they working or not) but also Rationality (Does the sensor signal make sense considering everything else going on in the engine?). I was told today, this is the major way the PCM knows if emissions standards are out of whack while in Open Loop mode, being the O2 sensors signal are COMPLETELY ignored during Open Loop Modes. (FSM & Chrysler Engineer)

In other words, let say the air intake temp is at ?x? and the coolant temp is at ?y?, the PCM expect the map to be at some value (range) of ?z?. If it isn?t, if it comes in as an ?a? it doesn?t make sense, and the PCM sets the MIL light.

Kind like going wheeling in Johnson Value and expecting your Jeep to be more then a bit dusty when you get off the trail, but finding out it is really covered in mud! Sure it?s possible, maybe 3 days a year, but highly unlikely. Therefore it doesn?t make sense. Put the MIL light on.

Management of the air fuel ratio while in any Open Loop Mode is via the Certified VET tables. NO, CO and other bad stuff are removed from the exhaust via the oxygen stored in the cat converter. (FSM & Chrysler Engineer)

It is only during Closed Loop Operations that the O2 sensors tell the PCM to dynamically change the injector bandwidth. (FSM & Chrysler Engineer)

How much that bandwidth is changed is dependant of another set of tables, that continuously change and become fine tuned over the vehicles life cycle, for the two Closed Loop Modes of Idle and Cruise ONLY.


I think this adds some clarification to both of our points. There are indeed memory tables that continue to change over time to reflect most current conditions, and yet there are also memory tables, which are changes once (or until flashed as described) in the first 50 warm up cycles.

Now the question becomes, ?Of how much real value is it to flash flush the PCM to reset those Open Loop Tables?? I don?t know the answer to that one.

Perhaps time will tell.

Feedback I have received says it makes a differance but how much is atributed to the 50 cycle tables vs. the long term fuel trim tables (40 cycles) I don't know.

Have a great night my freind,

Frank
Reply With Quote
  #52  
Old 04-21-2004, 07:24 AM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Hi Folks,

Just a short note on what is going on with this project.

I am currently waiting for a few parts to come in. One from Avenger, to replace a rubber hose that my blower was inadvertently shipped with, and a pyrometer (gauge and sensor) to be able to tune this thing via exhaust gas temperatures.

I am expecting these parts to arrive today or tomorrow and will get them installed as soon as I can.

The dyno runs looks like they will have to wait till the middle of next week as I have missed my scheduled window on the dyno this week.

Sorry about that.


But in the mean time here?s a picture!



I figured if Jeep can put Rubicon up on the hood edge I could at least make my Jeep match my cars.

Have a great day, I plan to, on my way to Keeneland with a very special guest.

Frank
Reply With Quote
  #53  
Old 05-08-2004, 07:50 AM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Hi Folks,

While I haven?t posted a lot on this project lately, the project has not been back burnered. In fact I have some new info to share.

Let me first start by saying, I had my Jeep on the dyno yesterday. This was an ?On the House? run to read and record peak Horse Power and Torque measurement prior to the ?tuning adventure? I am about to begin.

Here are the results.

Please note, I have done no tuning what so ever other then to increase the spark gap by 0.010-inch. (I will explain this action in a few minutes.) Other then the spark gap these are the results I received with a straight ?Bolt-On of the Avenger Super Charger?, right out of the box.



Peak Horse Power at the Wheels

Stock Engine = 124.3 HP at 4500 RPM
Super Charged = 187.7 HP at 4550 RPM

Net Gain = 63.4 HP
Net Gain as a Percent = 51%



Peak Torque at the Wheels

Stock Engine = 163.2 ft-lbs at 3000 RPM
Super Charged = 249.7 ft-lbs at 2750 RPM

Net Gain = 86.5 ft-lbs
Net Gain as a Percent = 53%




That said let me tell you what else has been happening here.

I had the opportunity to spend two full days with my Jeep over at my friends shop in Speedway, IN.

Joe runs an engine dyno tuning shop up in Speedway. (I think it has something to do with some racing that goes on up there.) His shop has 6-chassie Dyno?s and 6-engine stand dyno?s.

Unfortunately given the time of year this is, each was fully rented out in 24 hours blocks of time.

But we did some work, some testing and I did get an education.

Here is some of what I learned. Perhaps it may be helpful to others who have super charged their Jeeps.



Where I Started At

(Please Note: I had not yet run my super charged Jeep on the dyno when I went up there.)

I could not be more pleased with the performance of my Avenger Super Charger.

Having done super charger installations on other vehicles over the years I kinda knew what to expect. Most of what I was expecting, as far as additional tuning needs goes, I didn?t see a big need for.

Performance, based on the seat of my paints was and is indeed remarkable.

After re-flashing the PCM twice, and driving my TJ for a bit more then 1,600 miles the only down side I have found is an ever so slight ?Ping? which occurs between 1,800 and 2,200 RPM coming off a steady throttle.

Others here and via email have shared a similar problem, only much more severe then I was experiencing.

In my case this was hardly noticeable, again happening only when trying to accelerate lightly.


I called Joe and he told me drive it up there and he?d take a look at it.

First thing he did was take it for a five-mile test drive around the track. His diagnosis; ?Spark Timing most likely too far advanced.?


After letting the engine cool off we pulled the spark plugs. They read fine.

Joe disappeared for a few minutes behind one of the many privacy curtains in the building and came out with a micro fiber optical camera! (his place not only looks like a hospital ward with all the privacy curtains, but he has hospital type tools as well.)

Each cylinder was inspected using this tool. WOW! You can see everything inside, just as if the head was off.

There was NO Carbon Buildup at all, not on the heads, piston tops or the valves.

This procedure was done to insure the knock was not caused by pre-detonation, due to carbon build-up in my 85K plus mile engine.

As I said, no carbon build-up at all!


Joe had me re-gap the plugs another 0.010-inch. So I took them to 0.045-inch and put them back in.

After hooking up a data recording computer and taking out the extra O2 Sensor I installed in favor of a Wideband Lamda Sensor I took it out for a 15-mile test drive on the street

Guess what?

No Spark Knock, none at all!

I mean completely gone!


Back at the shop I asked Joe what happened?

He told me we ?retarded the timing?, across the board, by about 1.2 Degrees by increasing the spark gap by 0.010-inch to 0.045-inch.


My Continuing Education


I was telling Joe about others with the same super charger kit having very sever spark knock and that I wanted to try and understand why.

He had me pull my Stock Air Box, which was connected, to the Snorkel, and install a K&N free flow filter under the hood. Then I took it for a test drive recording all sensor data along the way.

I didn?t make the entire 15-mile drive. I couldn?t.

I thought the engine was going to break! The spark knock was horrific! It was so severe, it sounded like a bucket of bolts rattling around under the hood. A power reduction was clearly noticeable, even by the seat of my pants.

I felt like if I continued on with this I was going to break things so I limped back to the shop after about 10 miles.

When I told Joe what happened he gave me his typical smart reply. ?I Know?.

We pulled the data monitor he showed me what was happening.

The Intake Air Temperatures with the K&N filter sucking hot air from under the hood were a minimum of 55 and a maximum of 73 degrees F hotter, then the Intake Air Temperature coming through the Snorkel.


Here?s the explanation, as I understand it.

Warmer air is Thinner. Thinner air weighs less. Air that weights less requires less fuel, and More Spark Advance. (TO A POINT!)

Colder air is Thicker. Thicker air Weights More. Air that Weights More Requires More Fuel, and LESS Spark Advance. (TO A POINT

There is however more to it then Air Density and the correct A/F Ratio. Specifically the A/F Volume.

For example, 1 Ounce of Fuel and 14.7 Ounces of Air will give you an A/F ratio of 14.7

Also, 1 Pound of Fuel and 14.7 Pounds of Air will also give you an A/F Ratio of 14.7

But these two, identical A/F Ratios are not the same, by Volume!

Put too little A/F mix, by Volume in the cylinders, with timing too far advanced and you will get Spark Knock. (Joe says so anyway and I am willing to go with it till I know something otherwise.)


After looking at the recorded data, WITH the Snorkel, it appears Timing Advance was a hair more then it should be, at certain RPMS and Boost pressures.

Joe tells me that this is occurring at the point where vacuum is lost and pressure from the blower is just beginning to build. This is the transition from normally aspirated engine to a pressure operated one. This is also the transition from ?Cloosed Loop? to ?Open Loop? mode.

Why is this happening?

Well, as I understand it, based on Joe?s explanations, the combination of MAP sensor signal (which is only capable of measuring 1 bar, or one atmosphere) and IAT sensor signal are unable to provide the correct inputs to the ?Perfect Gas Law? to calculate Timing, and to a lesser degree on my engine fuel mapping.

The problem is greatly amplified when the intake air temperatures increase, as evident in the use of the free flow K&N filter and sucking in under hood hot air. Ignition Timing is just Too Far Advanced for this air temperature/density.


I asked Joe why, with the exception of the slight spark knock, it worked so well with the Snorkel.

He told me with the cold air coming through the Snorkel it was close, but it wasn?t right on the money.

Looking at the actual Air / Fuel ratio?s as read and recorded using the wideband O2 Sensor, it was easy to see there was plenty of fuel available from these 26 pound injectors. But just like with the Timing, the A/F Ratio is close, but not perfectly mapped.

At times, under high boost, the A/F ration was as Low as 11.9, which to me means the 26-pound injectors are quite capable of flowing the needed extra fuel for the blower. As I had suspected, almost across the board my installation was and is running RICH, with or without boost pressure.

The Ratio UNDER BOOST was in a range of 12.0 to 12.9 A/F Ratio, 95% of the time.

The Ration WITH NO BOOST was typically 13.0 to 14.2 A/F Ration.

As you can see both are generally ?Rich? mixtures.

The only time it runs lean is when going from transition, from normally aspirated to pressure mode, when that slight throttle increase induces the ?ping?. (closed to Open Loop transition.)


Joe disappeared behind a few more curtains and came out with a ?black box?. After connecting all the sensor up to my Jeep I took it for another test-drive with the K&N filter still in place.

WOW!!!!

The difference was amazing! Not only was there Absolutely NO SPARK KNOCK, but there was a remarkable performance improvement!.

I have to have one of these black boxes! (Well I thought I did till I found out the price!)

This ?Black Box? that Joe hooked up was a special type of Piggyback Computer that managed and monitored timing based on individual cylinder spark knock and the A/F ration for each cylinder using a knock sensor for each cylinder. Timing is advanced or retarded based on actually knock and controlled on a cylinder-by-cylinder basis.

It also had a 3 Bar MAP Sensor and required the Wideband O2 Sensor.

But for $3,800 I think I can live without it. Joe agrees.


As big a difference as there was in performance in my putting the Avenger Supercharger on my stock engine, there was an almost equally big difference (seat of the paint measured) with this ?Black Box? on the engine. Across the board, all RPM ranges, boost or no boost, my engine hummed like it never has before.

Being I have no intention of spending that kind of money Joe gave me his advice as to what I should do; Call ?Split Second? and purchase a custom built Fuel / Timing Calibrator Piggyback Computer.


(Please note I had already received this exact same advice from a gentleman named Hugh who has also done this Avenger Super Charger installation on a 4.0L Jeep. He was extremely pleased with the results he received.).


The FTC1-019 is a custom built Fuel Management and Timing Management computer that piggy backs onto the stock PCM. It come with it?s own 2.5 Bar MAP sensor and enable total management of the Fuel mapping tables (in Open Loop Mode) and Ignition Retard mapping tables across the RPM/Boost range

The FTC1-019 gets wired up to the crank and camshaft sensors, as well as the upstream O2 sensor and a few other things. Then you simply plug your laptop into it via a serial cable and begin to tune TWO, 3D mapping tables, one for Fuel vs. Boost Vs RPM, and another for Timing, vs. Boost vs. RPM.

As you tune these parameters you record them into the FTC1 as often as you would like by writing to the EPROM in the box.

When testing the results of your tuning effort the FTC1 records all sensor signal data in both data table and graphic overlay format to be downloaded and viewed on the laptop.

Taking the advice of both Joe and Hugh I order an FTC1-019 Timing/Fuel Controller from Split Second built to my Jeep?s 4.0L specs, injector size and boost pressure. It arrived last evening and I will be playing with it this weekend. The unit I ordered has an optional ESC control unit that allows me to force the Jeep PCM out of ?Closed Loop? engine management mode, whenever the Boost Pressure exceeds 1 PSI. (The transition window into Boost pressure from vacuum pressure.)

This is to ensure I can feed the engine a steady diet of fuel and timing both for performance, engine longevity and yes for emission purposes as well. (This is important to me.)



Joe?s Comments

It isn?t every day I get to pick the brain of someone as knowledgably about these issues as my friend Joe. In truth I doubt there are very many people in the world who are as knowledgeable or experienced in engine tuning of this kind.

Here are some notes I?d like to share regarding Joe?s opinion and comments of how MY Avenger Super Charger installation performs and what might be done to make performance and timing issues go away.

+++++26# injectors are more then enough if the Timing and Fuel Mapping are tuned.

+++++Fuel mapping, given the Stock PCM and the Stock 1Bar MAP sensor perform remarkably well. Not Ideal or perfect, but very operational and safe if you can retard the timing a few degrees.

+++++Ignition timing needs to be managed better. Ignition timing is too far advance across much of the boost / rpm range . This is a particular problem when migrating from no boost to a boost condition in the engine.

+++++In addition to the ?Spilt Second? solution for both Fuel and Timing mapping, there are other ways to manage the Ignition Timing available from MSD. Mallory, Accell, and a few other Ignition Management manufacturers. He didn?t get specific to models but a quick look through the Summit and Jeg?s catalogs and you can find them. I did.

+++++Anything that can be done to cool the intake air, upstream of the blower, such as a snorkel will greatly improve performance, have a positive effect on spark knock, and help to ensure engine longevity.

+++++Piggyback computers such as the Split Second? unit are by far the best solution to gain optimum performance and protection of the engine. Anyone reasonably skilled (me) should be able to get 90 to 95% of all available performance out of the engine in their driveway in one good day of tuning, The remaining 5 to 10% would require a dyno to help extract.


+++++Basic Super Charger Starting Points for my 4.0L Jeep engine.

Coldest intake air possible

Advance Ignition Timing to the point of spark knock. Then Retard Ignition Timing by 1.5 to 2 degrees across the board. This should generate maximum power without breaking things. This should be done at all RPM and Boost Levels

Target Air Fuel Ratio?s as follows:

No Boost = 14.7 to 14.0
0.1 to 2.0 psi = 13.5 to 12.7
2.1 to 4.0 psi = 12.7 to 12.5
4.1 psi and up = 12.4 to 12.2




That?s all I have right now folks. Daylight is burning here so I am going to go get another cup of coffee and install the Split Second FTC1 and see how this things works.

I will post more when I have something of any perceived value to share.

Have a great day.

Frank
Reply With Quote
  #54  
Old 05-17-2004, 02:01 PM
Daless2 Daless2 is offline
The king of shotgun debate
 
Join Date: Dec 2001
Location: Kentucky
Posts: 1,303
Hi Folks,

This morning I received on of those good news bad news phone calls.

The bad news was my Dyno slot for Weds had to be canceled (again!) for a real paying customer. The good news was, I had the dyno today till 12 noon if I wanted it. Need I say anything more?

Project TJ Kompressor is now done for the most part. In a moment I will be summarizing the results and giving a few well deserved thank you?s.


Last week I shared the initial Horsepower and Torque reading as a result of bolting on the Avenger Super Charger right out of the box. I was and still am quite impressed with this unit. It worked well, but like anything else I wasn?t fully convinced, after visiting with my friend Joe, that I had everything I could get out of it.

Here are the final results after tuning.



Tuning by Wire

I?m certain none of this will be new to some of the young folks around here, but you don?t tune engines like you once used to. Jets? What are Jets? Vacuum Advance? Advance Curves?

None of the old ways of tuning an engine for peak performance and reliability apply to a computer controlled engine.

At the advice of my friend Joe, and a new friend, Huge from the ?land down under? I ordered a ?Fuel / Ignition Timing Controller? from Split Second. This unit comes with it?s own 2.5 Bar Map Sensor and allow full management of the Fuel Injector Bandwidth and Ignition Timing (in retard mode.)

The unit also allows you to take control of the O2 Sensors when in Closed Loop mode AND Boost pressure is being generated.

The FTC1 is a black box I have hanging from the underside of my hood just above the stock PCM.

I will snap a picture later when my camera gets home.

It isn?t much to look at, but wire it up and connect it to a laptop to be programed it and it?s amazing what you can do with it.

I am not going to go into all the details of how to operate and program the FTC1 but will briefly explain how it works.

For more detailed info you can go to www.splitsec.com

The FTC1 lets you ?condition? the signals going to the Jeep?s PCM to reflect actual engine conditions WITH the Blower Installed, by sending signals the PCM can understand.

Why is this of benefit?

Well the PCM was initially used and programmed to control a normally aspirated engine. (no boost pressure)

Now with the super charger in place, the sensor signals being sent represent greatly different actually values, then the values that would be there without the super charger being installed.

In essence, the FTC-1 allows you to re-map your fuel injector bandwidth a ?plus or minus? approximately 50% of the range it would normally be operating in.

Larger Injectors, and more air pressure dictate the need to do this.


For ignition timing the FTC1 allows you to selectively retard timing based on engine RPM and Boost Pressure.

Both maps, Fuel and Timing are adjustable using a laptop, which plugs into the FTC1 and the R4 programming software supplied with the unit from Split Second.


Fuel maps are adjustable across the entire Vacuum and Boost pressure range, in my case from ?28.5Hg to 0 Vacuum (in 1 Hg increments) all the way up to 0 to 7.5 PSI of Boost (in 0.5 psi increments).

Individual adjustable increment can be made in 500-RPM increments.

Think of a rather large spreadsheet, with Vacuum/Pressure at the columns and RPM at the rows.

The cells in the middle represent the values you wish to be sending/adjusting to the stock PCM.

Talk about being able to fine tune things!


Timing works the same way, Vacuum/Boost along the top columns, and RPM along the side rows. Only with Timing the values of the cells represents the number of degrees in timing ?retard? you would like to ?subtract? from the engine at any given RPM and vacuum/boost range.

Later I will see if I can capture a couple of screen shots to explain this a little better.



The End Results

The following two charts reflect the performance of my 97 TJ 4.0L before the super charger, after the super charger, and after I tuned it ?by wire? using the Split Second FTC1 ? Fuel / Timing Controller.


Peak Horse Power






Peak Torque Power






Horse Power Curve Comparisons

Please note, I only have the data on the Horse Power curves for the Stock Engine and the final product, after the Super Charger and After Tuning by Wire (Using FTC1 from Spilt Second).

While I ran the Jeep for the super charger alone on the Dyno to get peak HP and Torque readings, I did not record the data for the Super Charger alone after just bolting it on.

Why?

Well, I am getting the dyno time for free, (when it is available) however, each time a recording is performed there is a $75 licensee fee that I must pay. That is getting expensive folks. Read that, ?I?m getting cheap in my old age.?

So, sorry but the funds are not unlimited. Thanks for understanding.

That said, here are the Horse Power Curves from just prior to the start of this project, and those that exist now.







Torque Power Curve Comparisons

Here are the Torque Curves.






As you can see from the results I have there is a significant increase in both Horse Power and Torque.

Was this an easy installation?

Well the bolt on part was, and for $3,800 I would have been quite pleased with it. Having spent the additional $500+ on the Split Second FTC1 controller however made all the difference in the world in drivability.

Prior to the FTC1 it was indeed powerful, now it is powerful and SMOOTH! Every bit as smooth as my other current other vehicles, which came from the factory with super chargers on them.

I?m happy with the results. Time will now tell if there are any negitive side effects as a result of this change. I expect there will be, as adding more boost and more fuel into an engine has to have some effect on its longevity.

How much? I don?t know.



Other Closing Thoughts

Air/Fuel Ratios

Using Joe?s guidance, and a borrowed Wideband O2 Sensor I tuned the FTC1 for fuel to match Joe?s recommendations based on Boost pressure.

I had to reduce the injector bandwidth for the vacuum portion of the engine, as the 26 # injectors where causing it to run rich.

I fine-tuned the injector bandwidth for the Boost Pressure portion of engine performs, however, these changes were minimal. It was indeed surprising how well the stock PCM allocated for this, especially once the 2.5 MAP sensor was add to the system.

While not reflecting exactly how I have all 200 adjustable cells set up, here is the guideline I used to get the A/F ratios correct.

Target Air Fuel Ratio?s as follows:

Vacuum/No Boost = 14.7 to 14.0
0.1 to 2.0 psi = 13.5 to 12.7
2.1 to 4.0 psi = 12.7 to 12.5
4.1 psi and up = 12.4 to 12.2



Boost Levels

The highest boost I recorded was 6.7 psi Absolute above atmospheric pressure, however this level of boost pressure is very rare with this system.

The highest boost pressure occurs in the early morning, when air is the coolest, and humidity levels (dew point) are at there highest.

Under full throttle (absolute Wide Open Throttle, No Load Conditions) boost routinely hits 4.0 to 5.3 psi, even at 85 degrees F


Fuel Mileage

After installing this system and driving my Jeep for a total of 3,200 miles I have a pretty good expectation as to what to expect on fuel mileage.

It has gone up, even with a heavy food on the skinny peddle.


Prior to the Super Charger Installation my MPG for the previous 10,000 miles of driving was 14.8 MPG.

My worst tank (not off roading) was 13.52 MPG, and my best was 16.23 MPG.


After the Super Charger installation, but before the Tune by Wire Exercise,, the first 1,862 miles brought with it an average of 15.54 MPG.

Worst tank was 13.71 MPG and best 15.93 MPG


After the Super Charger and after the ?Tune by Wire? effort mileage went up again to an average of 15.96 MPG.

Worst tank was 14.70 MPG and best was 17.86 MPG (all highway 65mph.)

Please note: These MPG figures, after the Tune by Wire effort are BEFORE the dyno tuning done today. If over time these numbers vary significantly I will post them.


I can live with those numbers, even if I have to use High-Test fuel now.



Closing Thoughts

Would I do this again?

?I? would. But please understand, I have done similar installation in the past. While not an expert by any stretch of the imagination, I did have a fairly good idea what to expect and what would have to be done to resolve some issues.

I would do business with the folks at Avenger Superchargers again in a heartbeat.

Their support has been terrific and constant throughout this project. When I needed to talk to someone about a technical aspect of this project Jack was always available and in no rush to get me off the phone. The same I can say for Ed and his support in other matters.

I paid $3,800 for this blower on a pre Moab Easter Week sale. I would do it again in a heartbeat.

I am convinced that ?tuning of the PCM and a MAP sensor capable of reading not only vacuum, but also pressure is required to get the most power out of this system.

However, I am not at all convinced that this tuning can be done by a super charger manufacturer and shipped with the blower. It just doesn?t make any sense to me, there are far too many variables.

Perhaps some level of vendor supplied PCM tuning can improve performance over no tuning at all, but given the different levels of performance experienced by multiple Jeeps with the same bolt on blower I have to conclude (at least to my satisfaction) that variables on each Jeep require individual tuning. One size fits all just doesn?t seem to be workable to me. (Just my opinion here.)

The 26# injectors shipped with this kit are more then enough to fuel my 4.0 L engine. Or so it appears.

I have a feeling larger injectors are being installed to address issue ?symptoms? without dealing with the real issues. I believe based on what Joe showed me the issue isn?t injector size as much as it is ignition timing being to far advanced during certain parts of the RPM range and certain boost pressures as well as air temps being too hot..


FTC1-019 ? The FTC 1 was custom built for my installation (engine size, boost pressure, ect.) There was a two-week wait for this unit to be delivered. It was to come with a starting set of both Fuel and Ignition timing maps for my installation, but for some reason it was shipped without these.

Being I received the unit on a Friday night I had a weekend to play with it in my shop. This was a bit harder to do then I though.

I fired off an email to Huge, who I met online as a result of this project. Huge was kind enough to send me a copy of his Fuel and Ignition Mapping tables to use as a starting point.

As I found out later, Huge is located just south of Sydney, Australia.

Thank you Huge, your mapping tables got me going down the Tune by Wire timeline in a much faster way.

I played with it for a week, extracting out as much power as I could perceive based on the seat of my paints, then I finished it up on the Dyno.

All in all I was able to get almost full power (up t the last 11.2 hp and 15.2 ft-lbs of torque) in my driveway without the dyno.

I have one more trip to the dyno scheduled for next week, to see if I can tweak this a little more. Once I am done, please be expecting a file with my Fuel and Timing tables.

I do not know how they will affect your Jeep and Super Charger Performance, but hopefully they will be a plus for you. (I?d like to repay your kindness in helping me out if I can..)


That?s it for now folks. I am certain I will have a few more comments to add as time goes on.

My next project will be to sand my hard top smooth, fill the fiberglass seams smooth and then Base coat Clear coat it the same dark green as my Jeep body. Fix the roll damage and dents too.

Why?

I like being different (and I need a project to keep me out of trouble). Besides the soft top is about to go on for the summer anyway.

Frank
Reply With Quote
  #55  
Old 05-18-2004, 04:53 PM
Scratch Scratch is offline
Registered User
 
Join Date: Apr 2003
Location: Bakersfield, CA
Posts: 196
thanks for the info frank. I've very much enjoyed reading it.
Bob
__________________
Living on the edge is one thing, falling off is quite another!
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Daless2 Project Rebuild - TJ at 98,000 miles Daless2 Jeep Friends Forum 8 11-24-2006 06:03 PM
My New Jeep Project Macgyver Jeep Friends Forum 3 04-14-2005 11:48 AM
AZ: Streetable XJ rockcrawler project f/s or trade Blatant Buy/Sell Jeep Stuff 5 07-15-2004 10:13 AM
Round spring project, almost there! ChrisO Jeep Friends Forum 16 07-15-2003 07:18 AM
Community G-Tech Project TObject Jeep Friends Forum 0 09-25-2001 06:34 PM


All times are GMT -7. The time now is 05:12 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
We are not affiliated with Chrysler LLC. Jeep is a registered trademark of Chrysler LLC.
©2001 - 2016, jeepbbs.net. All Rights Reserved. Privacy Policy