I did change the TPS....same issue before and after.

My fuel pump pressure is about 34....now, I have a cheap gauge from Harbor Freight, and it leaked at the gauge end...so the first time I tested it, it was reading 30, and when I shut the engine off, it dropped immediately...then I put teflon tape around the connection of the gauge to the hose, and got the 34psi reading and it stayed stable for a little while after I shut the engine off....

HOWEVER>>>>the 'new' (cheap ebay) pump has a bad check valve...after shutting the engine off for a while, it takes a while for the fuel to get to the engine....(I can either crank it for a while, then it starts, or I can turn the key to 'run', let the pump pressurize, and repeat 4 or 5 times...and it starts immediately).

So, the place on ebay is giving me a full refund..and I ordered a Bosch pump to replace it...so I'll keep you posted.

All the other stuff...new coil, and the stuff above (including a Seafoam treatment of the engine) made it run MUCH smoother....except for the small hesitations...

So...running out of stuff to try....change to the Bosch fuel pump, then maybe replace the capacitors in the ECU / PCM.

AFARR

 

run sea foam threw it gas tank oil and brake booster then go from there vids are on you tube to figure it out.

 

I had the same situation with my 93 sport. did the same thing you have done (swapped a bunch of parts). wound up taking it to a Jeep specialist. The problem turned out to be the timing chain was worn and the alternator was off like 2 teeth. not enough was wrong to really screw it up, but when it was running down the highway it would skip and jerk. it gradually got worse. i only had a check engine light come on twice but it went back off and stayed off. check your timing.

 

true i guess in the end might as well save the money and bring it to a shop right.... i might do the same mine is having trouble with timing i think just not acting right....

 

You guys know that thread is a year old? Sounds like his fuel pressure was way low.....

 

The cheap meter I had might have been off for the fuel pressure.

I replaced the ECM/PCM (Computer) with a similar 4L controller and have had no problems since then (thought I had updated the posting). Someone pointed me to a thread somewhere that says the 3 Capacitors die out over time and how to replace them. I may give that a try down the road since I still have the original ECM.

Probably why the computer wasn't throwing any codes...the computer itself was the problem...

 

i actually picked up a spare PCM from a junk , might as well throw it in and see what happens, i tried clearing codes last night by the old dissconnecting battery way been about 10 hours so, well congrats on getting your rig running

 

so yea battery disconnect thing dont work EVER fyi... also not PCM i did fix small vacum leak today that was nice but no changes!