got a good wheelin buddy who has a 93 wrangler with the 4 banger 5sp in it. We got in some deep water a while back and the thing started stuttering and stalling. We figured it was water in the distributor, and after we did the wd-40 trick and dried it out it ran fine for about a minute and then acted up again. We got a lean condition from the computer but it was smoking and smelled rich so we replaced the O2 sensor and everything seemed to be good for a couple days. Then of course the symptoms came back.

So the symptoms are: if you sit at idle for about 2 minutes you cannot accelerate heavily or it will stutter, spit and wont rev over 1500rpm. And in 5th gear at around 60 mph it will start cutting out and stuttering after about 10 minutes at speed. You can shift to fourth gear and get more rpm and it goes away. If you let it suffer long enough in 5th gear you will get an O2 code for a lean condition. Lastly it feels like there is a slump in the torque curve from 2800 to 3200 rpm no matter what gear you are in. If you accelerate at WOT (and haven't been sitting at idle for too long) it pulls good up to 2800 rpm then it feels like you got off the throttle and the inertia of the jeep carries you to about 3200 rpm and then it starts pulling again. But while its having one of its fits you can shut it off and turn it back on again (at idle, at speed it doesn't matter) and everything is fine for about a minute then it goes back to acting up, its almost like the computer reboots and runs off of some pre-set parameters and then starts pulling information from the sensors and its not processing the data correctly.

We borrowed a MAP sensor from another jeep and nothing changed, we checked fuel pressure and it seemed to be within spec per Haynes Manual, we checked for vacuum leaks, vapor lock, electrical shorts, and all is good. Could this be a dieing fuel pump, a bad computer? or another sensor doing this? any help is greatly appreciated I need my wheelin buddy back out on the trails.

Thanks
Dave

Could this be a dieing fuel pump, a bad computer? or another sensor doing this? any help is greatly appreciated I need my wheelin buddy back out on the trails.

Thanks
Dave

Could be any of these. Any chance you got water in the intake. Ive seen a hairline crack in a piston that gave similar symptoms. Water doesnt compress, something's gotta give.
Edit: just noticed you said if you shut it off and restart it runs fine for a while. I would check the fuel filter. You said the pump is fine. Check for dirty injectors

Something else i found. doesnt cost anything and worth a try. http://www.jeeps-offroad.com/f41/computer-reset-ecu-6026/

try this, Disconnect the battery completely for about 2 hours and see if the ECU will reset. I agree with injector cleaner in the fuel system with a new fuel filter. Double check your pressure at the fuel rail while idling and under quick throttle blibs to see if your within spec. If your really getting a lean code, I would start looking at dirty injectors as mentioned above. How many miles on Jeep? When I removed my injectors to replace them during my project, they didn't look so good at 120K Plus miles.