Red River T

Been meaning to post this over here too, been having a lot of trouble with satellite internet, and with staying awake.

My 97 GC 4.0 began to shut off occasionally about 3 week ago. I thought I would do the PCM plug "contact finger tightening" fix. I didn't have a dental tool, but a pick I thought would work. It was too large to get down in behind the "fingers". Plus, my reading glasses don't magnify enough, I've got to get a magnifying glass (or a microscope, LOL).

I ended up deciding to use an emory board to sand the pins on the PCM because they looked like they had a lot of oxidation. It seems to run a lot smoother and hasn't died or missed/stumbled since then (knock on wood). I've had 8 starts/turn-offs and driven a full week's worth of miles for me.

Unfortunately, two of the little retainer clips that hold the harness plugs to the PCM disintegrated, so I had to use the cable tie method to secure the plugs, thus I can't be sure which "fix" is responsible. Prior to this repair, I could make it stumble and die by wiggling the plug closest to the engine.

I don't know if I'll try the finger fix again if it keeps running well.

Red River T

Then a few days later, I posted this:


Might have spoke too soon. This morning when I started it, it ran for 15 or 20 seconds then shut off. No stumble, miss, shudder, just went completely off. It restarted right away though and I drove to work and back (21 miles total) without a hiccup.

One other point to make (and probably jinx myself on this too), I got this Jeep at the end of April and I don't remember if it has been doing this the whole time or if it started over the summer, but sometimes (most of the time) when I turn it off there is a shudder from the engine. It's severe enough to get your attention and you can hear almost popping noises, louder than the normal exhaust "notes". However, since I sanded the PCM pins Sunday I haven't noticed it do this. It actually sounds quieter when running too (or I'm imagining things)

Red River T

I keep jinxing myself, LOL. I got a CEL 2 days ago and I had one of the hard jars while driving for the first time since cleaning the PCM pins. I had filled up the last 2 times with 100% gas and I haven't had the dying after start-up problem, though I have had a couple of the shuddering shutdown episodes, mild ones.

Getting re-furbed 703's soon.

FYI, I bought a eHerko fuel pressure regulator/filter and afterwards I had high pressure, ~54 on O'Reilly's gauge and ~56 on AutoZone's brand new one. Guess I'll end up buying a new Bosch pump module when the aggravation adds up to > $170.

dave1123

The scourge of freedom, fixing your jeep!

Red River T

Thursday evening 2/5 I checked the codes and had 2, 0420 I think, the catalyst system below threshold and 0351 coil primary/secondary circuit. I've seen both of these before but this is the first time I haven't had 0300-306 misfires codes. My coil is an MSD I installed in early Oct I think when I had the short in the crank sensor wires. Early in that saga I got the 0351 code and got a warranty replacement for the MSD coil I had installed in June. Oops!

Last night (Fri) I had my first problem in several days. I started it and was messing around with cd's, so it ran for a minute or so, then went off. There were a couple of bumps as a some of the cylinders fired (I guess), so it was a little different than what was happening at the beginning of this episode. It was just going off, no stumble or anything. I could be driving along and feel it slowing down. When it would shut off shortly after starting, I couldn't "catch it" and keep it running by giving it gas. It would shut off anyway.

Red River T

OK, for the past few weeks I've been battling a dying while driving problem. I guess the episode described in Post #5 above was the first shot. A new negative battery cable improved the situation. Cleaning the connections on the back of the alternator and on the PDC input terminal seemed to improve it. My CPS showed 3750 ohms, so I put in a new Mopar, and that seemed to help. "Improve" and "help" as far as reducing the severity of the episodes and having it restart right away, it is still dying occasionally. It also got a new cat, muffler, and O2 sensors, plus I patched the cracked header by wiring on 0000 steel wool to try to mitigate any air getting in.

However, other than one time when it was definitely missing due to this new problem, I haven't gotten any 0300-0306 codes since I cleaned the PCM pins, and I used to get them every few days. And most times had not noticed a miss.