Car Tech forum: 1998 Jeep Grand Cherokee Stalling Problems

Ive got a 99 Grand Cherokee that encountered the stalling problem last May. I have a small child that was in the car with me and so it was a very serious problem for me so I thought by taking it into the Jeep dealership and having the experts diagnose the problem it would be worth to spend the extra money.

I never did the search on the web so I did not think this was a widespread epidemic but the service department said pretty much the same thing as most of the other people said who reported this problem. They never would acknowledge the stalling because they could not duplicate it, but they made some recommendations that would result in me spending ~$1700 to replace the computer and a crank sensor. It was bugging me to spend that much money without having known the root cause so, I opted to only replace the crank sensor for ~$550.

I have not found a good website for people to report symptoms and other variables leading up to these mysterious problems, but I will say that it was very hot out when the car stalled and I was probably driving it for ~20 minutes through the city with the AC on. It is colder out these days and I have not had any problems with it. There was also a posting on Edmunds.com (http://www.edmunds.com/insideline/do/Drives/LongTerm/articleId=44026) of a gentleman who claims he replaced an oxygen sensor in his 2000 Grand Cherokee and it resolved his stalling problem. That will be my next thing to try.

It is a bit frustrating that Chrysler will not acknowledge the failures and provide a solution. I am more than willing to spend the money for the fix if it is the true fix. It is dangerous to know a car will stall in traffic. There is a sense of liability on Chrysler for having so many complaints and not investigating the root cause.

mmickelson

I have a 1996 grand cherokee, 184,000 miles. Last year it frequently stalled at idle, especially if I put a load on the engine such as turning into a parking spot and activating the power steering pump. I did the usual trouble shooting trial and error routines like tune-up and such. Nothing helped. One day the car wouldn't start at all so I had it towed to a garage. The mechanic found that the starter switch housing had a metal tab broken off. He replaced the starter switch and the problem has never repeated. This may not be your problem but it's another thing to consider.

I had the exact same problem on my '98 Grand Cherokee Laredo 5.2L V8 (ZJ).

I had read about the 2 screws fix. I took out the PCM and discovered that my GC doesn't have those 2 screws. But when I put the PCM back in, it worked, so I attributed it to reseating the connectors.

It worked for a couple of days, then started stalling again. I found that taking the neg terminal off the battery and then reseating the black connector, the far right one, it worked for awhile.

Well, it got worse and worse, and I got tired of constantly having to reseat that connector. I searched the forums again and found a writeup on what someone else did. The second suggestion was to reset the computer (PCM). I figure it's equivalent to rebooting your computer...when in doubt, reboot! To do this, he said to disconnect the positive battery terminal for 1 hour, then said that someone else recommended 4 hours. I took the positive terminal off when I went to bed. The next morning, about 10 hours later, I put it back on. It hasn't stalled, missed, hesitated, or had slow cranking problems in 3 days! It's a simple thing to try and it's free!

It seems like there are several components that can cause this stalling behavior. The symptoms are the same because the PCM is what is sending bad instructions to the engine. It could be the PCM, but it could also be any number of sensors that feeds information to the PCM. In my case, I had replaced my PCM a year before my stalling started, and I was hoping it was not dead again. So I replaced the crank position sensor (no change), the throttle position sensor (no change), the MAP sensor - BINGO! Runs perfectly ever since. I even get better gas mileage now. (it was a 5-minute fix, literally)

Other items could be a bad coil, cam position sensor (in distributor), distributor, O2 sensors (usually get a check engine light), fuel regulator, fuel pump, fuel filter.

Good luck.

My Problem my truck just turned off out of the blue. I was using it just fine worry free. I pulled up to a gas station and it just shut of on me without any warning. After that, It wouldn't start up again. It would crank over, but not start. I do my own mechanical work so the first thing i checked was the fuel pressure. Pressure was good. I changed the spark plug cables and distributor cap/rotor because there was no current. No luck. I installed a brand new crank sensor and a pick up coil. no luck I the found t burn out resistors. I replaced them and BINGO!!, for now...? The truck started and ran fine, but 15 - 20 minutes later it started misfiring and getting lazier and stalling more and more until it died on me. Would not turn on after that. 1 hour later, it would turn on with no problems at all. 15 minutes after, same thing would happen. I ordered a new computer after checking the fuel pump and making sure the fuses were the correct amps. Still no luck. Please help. anyone out have any suggestions?

Te truck is not overheating, but I'll try those suggestions. Thanks

do you still have your GC? Did you ever have any more problems after fixing the MAP sensor?

I have a 99 GC Laredo and had the same exact symptoms. First stalled a couple of times, I cleaned the three computer sockets and it seems that i have no more issues for a week. It could be because of the battery since i had to disconnect the battery for a couple of hours. How did you diagnose the problem at the end? Is there a way to understand whether this is battery problem or other issue like crank position sensor? Thanks for your help in advance. Really appreciated...

This worked on my 1996 Jeep Grand Cherokee.I had just got a new PCM from the dealership.It still did the same thing.It would crank over with no problem but just no gas.Checked the fuel pump it was fine.New crankshaft position sensor replaced the old one started right up.Just after a while it would stall at anytime without warning.When idiling it seemed worse,so I replaced the idle control valve.Still same problem til I did what this caption suggested.I backed those two torquex screws out a 1/8 of an inch.Then I put RTV black around the screws.Started it up and it has been over two months without a single rough idle or anything.
THANK YOU SO MUCH.

Hey guys, I'm a GC owner too, 1998 GC Leredo. Mine has the same problem. I've had the crank shaft censor, the ignition coil, electronic pick up (under the distributor cap), and the muffler replaced. The stalling continues. My mechanic told me that he works on GC's all the time with the same issue. So the last time i had it in the shop he told me to start it then he shook the computer, and it started to stall. So the problem is in the computer. If you try and crank it over and over again it just burns out the ignition coil. So one thing leads to another. So the easiest thing to do is to swap out the computer. The down side is that no one will touch it or make a replacement part. So long story short, until you get rid of that Chrysler POS just be sure and stock up on crank shaft censors, ignition coils, and pick ups, cause it's never gonna stop. I told my dad about it and he ended up putting a piece of wood between the firewall and computer. It worked for a while but it's acting up again.

This may be the one that my mechanic used on my '98 GC. Anyway, it's been at least 10 weeks since the replacement, and I haven't had a single stall. I'm keeping my fingers crossed.

I haved used this business (http://www.autocompdirect.com/default.aspx) for a rebuilt ECM and they were very resonable. I even got a "one time" exchange because I don't install the crank sensor properly, I blamed it on a bad ECM from them. They exchanged with no questions.

http://www.topix.com/forum/mesa/TTC3KFC4OII4HPC1G

Love my jeep. No problems till it turned 170,000 miles. Now the rear end smells like gear oil, grinding noise at 65 mph. It began the stalling poblem mentioned. Replaced both O2 sensors, Coil, plugs, wires, cap, rotor, crank sensor, throttle sensor, ECM, Muffler, and fuel pump. Hoping to get another 50,000. right? Wrong!! Still stalls, still hesitates and back fires. Need another mufler now. Wigle the ECM wires and the connections are loose. Engine will shut off. Placed a thick pieces of styrofoam between wire connectors and windshield washer jug. (wedged in tight) No help. Dont want to spend any more. Checked for codes and machanic says needs new Cranck and Throthle sensor still. Got ECM from Nappa and had dealer install and code it. Got other new parts at Advanced Discount Auto with waranty but dont know if it worth the additional work. I miss my '70 chevy truck.