Alright everyone. I cant find any information on whats wrong with my jeep. Ill start off saying that I have replaced the following: Fuel pump, computer, CPS, TPS, wires and plugs, distributor cap and rotor, fuel filter, spark plugs, ICM and base, MAP sensor, and i have repaired my vacuum lines. Okay so here's whats going down. I'm driving down the road at about 55 mph. Then its almost like the fuel shuts off for a split second then resumes. but it seems to happen only when I hit a bump. It does it at lower speeds sometimes but mostly at somewhere around 55. ITs a 88 xj. AW4 tranny

 

wiring

 

Drive a steady speed and time how long in between these events. If it's the same time each pause, it's probably the O2 sensor. The engine could be going into and out of closed loop. I had a similar problem for over a year and then figured it out. It might be the same as yours.

 

Run the motor in your garage. Put on leather gloves. Start shaking and wiggling wire harnesses and plugs. You might find your stutter. Also... as always... check and clean all your grounds!

 

I've had that stutter for years and over 200Kkm.
Havn't found it yet. Sometimes goes away, sometimes will stut several times on one trip.
I considered it the torque converter lock up? But havn't got a for sure on anything.
Mine is at about 1600 rpm, travel steady, let off gas lightly, one very quick stut, the jeep carries on like normal. Try to induce it, can't, then turn your back on it, stut.
I stopped being annoyed and surrendered. I'll post if I ever find a true cause.

 

I had an 88 some years ago. Got cheap from a family member due to its bucking bronco imitation. Every now and then it was as if the engine power shut off and turned back on rapidly. buck buck buck. Took some time to find the issue. Mine was the EGR valve. There is a small metal tube that take some of the exhaust pressure and uses it to control a vacuum valve to operate the EGR valve. This tube was plugged with soot. Took it loose and shot some carb cleaner through it along with a piece of wire to clean it out and reassembled the problem disappeared. When plugged with soot it caused the valve to act like an open vacuum leak. I found this by plugging a vacuum line and driving the vehicle. one vacuum line at a time till the problem went away then I was able to zero in on the problem. Yours may not be vacuum related but its worth a shot.

 

Thanks guys those are good ideas. So i have a new O2 sensor. I have done the shake and rattle wiring with no luck. I was thinking it could have been a loose distributor wire or plug wire. Something to that regard but that turned up wrong and all i was successful at geting was a shock when i touched the ICM. Anyways. I was wondering about the EGR and parts related. Im willing to try anything. BTW no im not going to sell this damn jeep. I was just mad when i wrote the post.

 

Have you performed my Tips 1 through 5 and 27?

27 is a good one to do.

 

I have a Dodge truck that has done that since new (03 101k). I don't know if it will ever be figured out since it goes months without a occurrence and then it does it one time only. Since it happens so seldom I have learned to live with it.

 

Yessir cruiser54. Ive followed your tips religiously.

@boatman - yeah ive heard of just dealing with it. But as a mechanic/ machinist. Living with something F'ed up starts to make my eye twitch. lol. I have to figure this problem out.

 

Hey all first post here but im and old hand with jeep and Chrysler. i had a 96 do just this sort of thing and it turned out to be the map sensor grounding internally. only code in the comp was multiple misfire,,,,, aka hey I died!!! just a thought. you could see the injector pulse go away for just a split sec on the scanner.

 

Just a word of advice from anyone that tries this..... Make sure your garage door is open during the process