Car Tech forum: 1997 Jeep Grand Cherokee problems.....please help

might be fuel filter,the only problem with that is they only have one and it's in the gas tank

I owned the exact same car, same year, same model. Still hate it.

Anyway... Sometimes even if you replace the coil, it could still be the coil. You can check the coil with an ohm meter, sadly I don't have the specs with what you should read on hand.

Other than that, there's two possibilities. Bad Cam/Crank sensor. If either goes bad, it can confuse the PCM into thinking it's time to fire a spark plug when it isn't, which in turn makes the computer thing the coil or plug isn't fireing when it is, causing a coil failure. I do not know how you can check the sensor on your own.

The other is a bad PCM. One way to check is if you get the car running, you open the hood, and lightly... *LIGHTLY* tap the PCM with a hammer. If it starts screwing up or stalls out, your PCM is bad. DO NOT beat the crap out of your PCM with the hammer to check it. I got one back with hammer imprints all over it. Of course it didn't work.

Sadly, the answer you don't want to hear is this: Intermittent failures are the worst most horrid things. Your best bet is a dealership. If you take it to a independent shop, they might change 20 things and never fix the problem, yet charge you tons. And even a dealership might have a hard time nailing down the problem, but it's still your best shot.

If you are bent on trying to fix it yourself, go to a junk yard and get a Cam sensor, or crank sensor. I would not advise getting a junk yard PCM unless you know for sure it's the problem, or if it's dirt cheap. I mean way under $100.

I had the same problem on my 5.2 97 JGC Lim and had a hard time but here is what I did. Also I only noticed this problem when it got below 40F. I first pulled off the Throttle body and cleaned it all out. I cleaned the IAC Idle Air Control Sensor put it all back together and it worked at first for a few months. I started to have the stall problem later on and just bought the new $30 IAC and the car has been running problem free, i guess, since then. Good Luck.

I have a 97 JGC w/ the same problem. It happened a bout 3 months ago and I did a complete tune up: plugs, plug wires, dist. cap, rotor button, and cleaned the throttle body really well. No problems since until last week, now it is doing it again. I replaced the coil and it did not help. I can disconnect the battery for a few hours and it will run good for a while but the problem returns. I understand that Jeep recalled the PCMs to be re-programmed about 2 years ago. So that is my next step, to find out if the previous owner took it in the recall service. By the way, a new PCM is $178 at AutoZone or Advance Auto.

Well I called the Jeep dealer and they said there is not a recall on the PCM. They also said if it were the PCM that the check engine light would be on. Mine is not on. Anyone else have a PCM problem w/o the check engine light coming on?
They said about the only things that would cause the stalling out w/o the CE light would be one of three sensors (cam/crank or ??? -forgot the name he mentioned). He claimed they could run diagnostics to pinpoint it so I may roll the dice let them check it.

My first bit of advise would be to not listen to anything the dealship has to say. I dont think they can even know what the pcm does. I had one dealership tell me that the pcm had nothing to do with any of the problems i was having. But no, My check engine light did not come on until 3 to 4 months after my problem started, and it did not stay on. And their diagnostics are just as crappy as their pcms. They will tell you it is the coil, crank shaft sensor, distributor, rotary, and the list will go on and on, as will the bill. The best advice i got was from these forums. check out the other threads, read them and just go ahead and change the pcm and o2 sensor. it will save you hundreds of dollars in useless repairs and tons of time. and dont spend hundreds on a mechanic to do it for you. on the other thread that has over 600 post you can find how to change it your self, it is simple and easy to do. I done mine myself and know absolutely nothing about vehicles. i could not change my own oil if i had to, but i changed the pcm all by my lonesome self going by the advice of people on here. Much more than i got from the dealership or any mechanic.

I have backed out the screws and my JGC ran great and trouble free for months. Then the issue started back in. Be sure to actually replace those screws with shorter ones. I think with mine just backed out something rattles loose and now I have the same problem and I took the screws completely out. I will check to see if I am recalled but if not, it looks as though I will just go purchase a new PCM from Autozone.

I have been experiencing same problems. Going down the road, die sometimes 3-5 sec. then fire back up, sometimes backfire sometimes not. Sometimes in morning turn over but wont start, come home from work and will start right up. Replaced o2 sensor,crank sensor, coil,pick-up in distributor. Been thru most wiring harness under hood for broken wire,nothing found. Hard wired from battery to coil, still same problems. Unplugged pcm terminals no arking on posts. While running wiggled pcm terminals ,tapped with hammer, no problem. No consistency, weather,outside temp.,length of driving. Can anyone help? 1997 JEEP GRAND CHEROKE 6 cyl. 4wd

what did the auto zone PCM cost. the one I go to is either tired of seeing me or happy to see their best customer. Depends on whose got the counter at the time. I should probably buy stock.

i got mine at autozone, it was $200 with an $85 core charge. so far no probs yet. but its only been 3 wks. have u checked out the other thread on here, has like over 300 post on this problem? has lots of great info.

I just worked on a 97 JGC with similiar problem and found the information here to be very useful.
The vehicle I was working on was difficult to start and would die after a few minutes. I checked the PCM connecters and found them to be poorly designed. The harness is heavy and puts a lot of strain on the connecters. I decided to try a cheap fix first. I wrapped long cable ties around the PCM and over the connecters going top to bottom. This secured the connecters and kept the harness from dragging the connecters down and causing bad connections. I don't know how well this will work yet but the vehicle I was working on seemed to run smoother, start easier and run longer. I'm unable to follow up on this possible fix as the vehicle belongs to a dealer. This may work if the PCM and the connecters are still in workable condition. Otherwise you will need to replace some parts. The reason this problem doesn't turn the service engine light on in some cases is that the loose connections may be cutting power to the PCM as if the key was turned off. I hope this works and saves you some money and aggravation. Be sure to use good quality cable ties at least 1/4" wide and pull then tight. Good Luck

I have a 1997 jeep grand Cherokee that burnt through 3 PCM within 7000 miles total unfortunately only one was under warranty. Jeep has a copilot they can put on your car to diagnose the PCM problem. But are now denying they own them.
Chrysler needs their rears sued off. Jeep only has 110,000 miles.
Problem is when the PCM blows it gives false readings like o2 sensors, coils etc and you spend a fortune chasing it down.
Dump the jeep 1997 as fast AS POSSIBLE WORSE LEMON JEEP HAS EVER MADE. tHE pcm BY CHRYSLER ARE DEFECTIVE