TJ acting up

Its mad at you maybe?? Needs more attention??

-jenn

Sure, lay a guilt trip on me because I spent a little time with a sexy late model, low mileage rental in another city...

You guys are nutz....lol.

Jerry S.

I did the same thing last week in paradise but came home to my best girl....

A-hem...

We are not all "guys". ;-)

-jenn

If anyone is interested.... ;-)

The magic box said my TPS was bad. Replaced it ($51)...no joy. Same problem persists. Still can't get a fault code from the on-off trick. Guess it goes to the dealer next week. Damn....

Jerry S.

I had symptoms very much like that when I got my TJ back from the dealership, when they did some recall work on it. Turns out they really screwed up my computer, and blew 2 injectors. I have no idea how but luckily it was before I did all the lifting n such so it was under warranty. But OH they did try to blame it on me but I was so miff'ed I said that it didn't have a problem until they got their hands on it and that I wouldn't even take it back until its fixed.

Troy

You didn't get ANY codes? You should have, at least, gotten a code that there were no codes...... Perhaps the computer is the problem?

Dyslexia Bill? Or is that 'ol "Sometimers" kicking in and ya can't remember what ya forgot?

LOL...

Jerry S.

The TPS will give you bucking or drop-out at a particular point in the gas pedal. RPM related problems are timing. Timing is the Crankshaft Position Sensor

CPS problems usually result in a no-go after heating up and eventually simply won't start. Coil problems manifest with engine temp. The warmer things are the worse it gets till the coil frags. Rotor problems (like oil in the distributor or cracks) usually give stumbles at certain RPMs. Sticky or slow injectors will also cause problems but then usually above a certain RPM. They certainly can cause a cylinder to run lean at high speed and that can cause knocks. Didn't sound like you had that problem.

Then you are looking at either a harness ground problem or voltage problem. With a digital ohm meter you can check the resistance of the ground side to the block and the voltage provided (5v).

I'd need the wiring diagram to get you closer.

Still, I'm leaning towards a bad coil or plug. That causes all sorts of bucking and will not set any codes.

Other thing, get a mechanics stethoscope (or a bit of rubber tube) and listen to the injectors. Make sure they all are ticking.

Mine doesn't give codes - built June 1998 per build sheet.

Dave Milne, Scotland

Thanks Doug, you gave me the best info! Fortunately for me the Jeep appears to have "healed" itself. My plan was to pull the coil this evening and test it. When I got in the Jeep this morning it ran fine, no hesitation , nothing, but the Check Engine Light was still on. When I went home for lunch, no light and it runs fine. I wonder if the computer just needed to re-map after the new TPS was installed.

Jerry S.

Erm.. yes it does. I forgot about that. :/

Before you drive anymore do this.

Turn the ignition to on, (engine off) Get under the hood and move the throttle plate all the way open and hold it there for a few seconds then slowly cycle it between full closed and full open about four times. Then get in and turn the ignition off. Then start.