JU Question - Spark Plugs?

[kranky_kel]

There is such a huge selection of Spark Plugs out there. Which ones help out the 4.0 the most? I have thought about the Bosh platinum, the Champion Truck Plugs, etc...

I don't care of they last 100,000 miles, I just want something to help with my excessive unburned fuel at low RPM's (and/or torque/horsepower).

[Robert J. Yates]

I am using the Champion Truck plugs to good success but I have to say that you need to look elsewhere to solve your un-burned fuel issues. Plugs will only do so much to help that. Do you have a carb YJ or FI?

[kranky_kel]

I?m running a '94 YJ 4.0 with 103,000 on the ticker.

This problem has only surfaced the last two years. This year I barely passed emissions (barely, I mean one more hydro-carbon molecule/million and I would have failed). My jeep passes emissions fine at high RPM (2500) at idle it spews pollution. It is tough to drive it around with the top off without reeking of exhaust fumes.

I have thought of going with new plugs and Accel cap, coil, and rotor. It has new plug wires.

I have had a heck of a time finding a solution. Some thoughts have been a MAP sensor or Idle position sensor. It back fires frequently when using engine compression to slow down.

[Tumbleweed]

Kelly, take it down to Ken Phillips at Anderson Auto. He has a diagnotstic computer that can tell you exactly what the problem is. sounds like a MAPP sensor or O2 sensor to me. BTW he drinks Crown Royal sometimes. Hint.

[kranky_kel]

DOHH!
I forgot about Ken. His shop is only a couple of blocks from my work. I'll stop by tomorrow at lunch. Thanks Don!

(FYI, the O2 sensor is only a year old, that was my first attempt at fighting this problem)

For other info...
My jeep is no drag racer below 2500 RPMs, but after 2500 RPMs, hold on. It takes off like a rocket.

[Tumbleweed]

Kelly, they go to lunch at 12:00 sharp and don't want visitors, etc. until after 1pm. Their only chance at peace. Just a heads up.

[Robert J. Yates]

Seeing that you have FI, have you ever used any carb cleaner on the throttle body? Ever have the injectors flushed or use and injector treatment in your gas?

While a new rotor, cap and plugs will help along with new wires - you have something else going on, particularly if you are having a tough time on the emissions issue. Get it scanned and let us know what you find.