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