JeepGC1995

Hi, I have a 1995 GCL 6 cyclinder 4.0 liter. 2wd. My problem began with the jeep being hard to start. At first it just took a little bit to get her started then she would run fine. Then she began to stutter and idle rough.

Put the jeep in drive or reverse will usually cause her to cut rite off. If i let her sit for a couple of hours I can crank her up and drive her until she warms up to normal running temp then she chokes back down

When I do get her to crank she idles super rough..but if i try to rev up the engine, she will just choke down. Sometimes by patting the gas i can get the rpms up over 1500 or so and she runs smooth.

I thought "ok, time for new plugs i guess". After a new set of plugs. Bought a spark plug gapper and gapped the to factory specs and changed the oil while i was at it. No change. Replaced the battery and added in SeaFoam to clean up the injectors and whatever else was gunked up. No Change and was getting worse. Ok I found out that the PCM can short out due to the screw making contact.

After removing PCM from firewall and it still having the same issue. I reattached it and cringed for the what I hoped it was not. After checking the pressure on the fuel rail and it was @ 40 psi I thought i had it nailed. I got a new fuel pump. Ok changed it out. and No change. I could not even drive her to the parts store now > . Then the parts guy suggested that the fuel pressure regulator was bad. Replaced that and still no change. Fine...Possible clogged catalytic converter. Pulled off the O2 sensor and got no improvement.

Im really beginning to lose my patience..Btw the check engine light is not on and no error codes. I have also visually checked my fuel line for kinks and crimps with none found. ANY help is needed. Thanks ahead of time I look forward to hearing from anyone.

Forgot to mention that I also changed the fuel filter. And Im not hearing the fuel pump come on, but then again I never was able to. Im getting 42 psi to the fuel rail if that helps. Thanks ahead of time.

JeepGC1995

Anyone have any ideas?

nick_n_ii

I had all the same problems on my '94 ZJ, after changing just about everything I could found out it was the PCM.. Replaced the PCM and all the problems went away.

Hate to say it but yours sounds lie the same problem as I had..

JeepGC1995

Just got a New PCM in today. Not the one out of Florida. and the problem did not go away....anymore suggestions?

mxw1

My daughter's Cherokee was doing similar. Have you tried replacing the crank sensor? They cost about $70.

I replaced a ton of parts trying to fix hers until I found out the problem was a corroded ECM connector. I had several of the tiny pins on the computer that were corroded. I believe #4 and 7. The female connections in the harness plug were also corroded and one of the female connections in the harness had been recessed back a slight amount, causing a bad connection.
I couldn't get a new harness but found a used replacement at junk yard; replaced harness, problem solved.

Look closely at your connections, take the computer out (it's only 3 screws) and look closely, the pins are very small and hard to see, check every female socket in harness connector, for corrosion and depth, compared to the others.

I think this might have been a problem from the factory.

e-mail me, if you need help.

Mike

ndo

I'm having the same problems with my bro's zj. Ive T/S it down to the 60 pin connector but still haven't found a way to fix it. Ive already trimmed the bolt an 1/8in. I can get it to die by shaking the connector i just cant pin point which pin is the culprit. Is there a way to push the sockets out of the shell so i can connect them individually any suggestions ? He lives in Cali so its tough to keep flying out to work on this.

JeepGC1995

Hi, I finally broke down and put her in the shop..turns out it was the coil pack! a stupid $40 part.

Least im up and running good luck to all. If this fixes yours please post back here