Car Tech forum: 97 Jeep Grand Cherokee stalling not fixed yet...

I had a similar problem with my '93 YJ. After hours of guessing it ended up being a loose bolt on the exhaust manifold.

No luck.
Today, it was low on gas, so I headed the station about 1/2 mile away, after a cold start. It sputtered a bit but as long as I kept the rpms up it ran ok. Pulled into station and the vehicle rocked a bit as I was pulling in the driveway. It tried to die on me. I thrw it in neutral, gave it gas...and it tried to keep running, but it sounded like the timing was way off...running at near stall speed. It finally backfired loudly and died. Got the gas....tried to start it. It died as I put it in gear, 2 or 3 times in a row. It finally started. Had it scanned.
Map sensor voltage too HIGH...and the primary coil code...faulty circuit again. ( misfire). Replaced map sensor. Disconected battery, turned on key to clear codes....and it still idles low after warm up.

Any ideas? Fuel pump?

Update:

New fuel pump and filters installed after the stalling got worse. Cleaned out tank too.

No change after the first 20 miles of driving.

It still dies as if the ignition was turned off.
I cant help but think there is a bad wire feeding the coil that heats up, since it wiring lies close to the engine block and the motor mount.

Anyone have any other ideas? This had gotten old and expensive !

Stalling mainly occurs when the outside temp is over 50 degrees and/or the engine is at operating temp....but not always.

I seen where this guy fixed all the problems with jeep grand cherokee....The ecm is grounded in some way the bolts are to long and it makes it short out a little but he took off all the bolts that hold it on and he hasnt had any problems with it in a year... So i did the same thing amonth ago and WOW it runs great....NOW IF WE CAN GET JEEP TO REFUND US ALL THE MONEY WE WASTED ON PARTS AND OTHER THINGS WE WOULD HAVE SOME MONEY .....Good luck and happy rideing mark

Here's an update, maybe with some good news for a change. Keeping my fingers crossed !

I have driven it a little over 100 miles in town now, since the fuel pump replacement, cleaning out the gas tank, and more recently, pulling the ECU connectors and spraying them with contact cleaner, backing out the OUTBOARD torx screw on the front of the ECU cover a bit more, swapping out the coil wire, adding a quart of oil and filling the tank with fresh gas.

It has barely tried to act up ( bucked and nearly died)....only three times...and it NEVER died !

So, here's ONE theory. It was the fuel pump and water in the tank.
After I had drained the tank and cleaned it out, I had to pour about 2 gallons of the old gas back into the tank in order to get to a station to fill up. Well, I went home from my girlfriends place that night( after replacing fuel pump) and didnt fill up on the way...since I dont live far and it was late. As I poured the gas back into the DRY gas tank, I tried to make sure I only poured the gas off the "top" of my gas cans, leaving any water in the bottom of the can, thus NOT pouring it back into my Jeep. I poured a little from each of the two, five gallon cans, so as to not disturb any water that settled.

I MAY have gotten a little water in my Jeep....but not much if any. And THAT could be the NEW reason it has tried to stall ( bucked and sputtered three times in 100 miles)...but did NOT stall. That was theory number one.

Theory number two is :

The ECU connectors were the problem, OR the outboard torx screw that I backed out even MORE could have been the problem ....and the bad fuel pump was only ONE of the original problems. ( along with water in the tank)

It could have, of course, been the coil wire that I swapped out. The plug wires were about 18 months old and I had bought a new set, that was sitting in the box...so I swapped out the coil wire only.

I wont keep you hanging, though. I will drive it and put some SERIOUS miles on it tomorrow and see if the bucking or the stalling comes back.......and THEN I WILL post to help anyone else that has had this trouble.

I'm guessing that I had multiple problems that overlapped and masked the main one. Time and more miles will tell. I just pray that it's fixed !

I'll be back soon.

Damian007 ,

I know it's a lot to ask of you, but would you please read my thread and offer up what you can for me?

I still can't help but wonder if the Power Window on the driver's door is the culprit. After everything you have replaced or fixed, a faulty wire or circuit interruption seem probable.

It could be that the plastic piece on the ECU was an insulater between Pos and Neg circuits and any moisture inside is creating a sporatic arc that interupts the voltage levels in the PCM.

An exposed wire in the power window circuit may also arc to ground at times affecting the voltage levels in the PCM.

Because the PCM is digital, a sudden drop of even .5 volts inside the PCM circuits could change outputs that trick the computer into correcting problems that don't exist or just send out incorrect signals.

I would look for any indication of overheated wires or hot spots on exposed metal near wires that may indicate a spark.

Other than that, I would doublecheck the alignment and tightness of the crankshaft sensor and do a continuity check on the wiring while wiggling the wire.

Sorry I couldn't be more helpful

Bruce - I have a similar problem to the one you're asking about; 90% of the time the power windows in my 1998 Cherokee Sport work from the driver's door switches only. They will occasionally work from the other switches, but this is infrequent.

Additionally, my gauges (sppedo, tach, odo) will sometimes die for short periods of time.

Hoping you may be able to help, based on your answers above.

This should help. I read the solution on the car forum some time ago when my 98 Jeep Cherokee had the same stalling problems. The screws are shorting out the board inside the ECM. What you do is back out the screws, located under the plugs, on the front of the ECM (husband says they're a booger to get to and they are torx head screws). Back out the screws 2 full turns and you're problems should be solved (just like mine were). Give it a try. The guy who posted this on the car forum some time ago is a GENIUS! My Jeep is back to normal

we have a 98 jeep grand cherokee 4x4 with similar problems...new spark plugs and a transmission flush really helped tremendously!

Well as you all know I do have a 1996 jeep grand Cherokee Laredo 4.0 straight 6 cylinder. Now do to my experience with these jeep/dodge/Chrysler nightmares is that when Dodge/Chrysler took over and they took a crap and my car came out. Now that I'm done venting a little this is what I have done so far with my jeep:

About 6 months ago I was starting to have major problems with my jeep. The first of it was the of course the stalling problem but mine loves to play jokes on me and while I'm trying to fix the stalling problem I realized one morning that I was leaking a large amount of red fluid.witch is know as transmission fluid, so I took a little drive in first gear down to the local transmission shop and they said I needed a full rebuild..awesome. So I got that replaced and then I was back on the road. Now back to my little stalling problem I first was throwing a code that was basically a secondary coil failure. So I went and replaced the coil pack the distributor cap, rotor, and the time senor in the bottom of the distributor. Spark plugs and wires and a new ground cable just in case. Ran fine for a little while then as I'm in the high way the jokes come back. I then realized that if I turn the off the key and then on again 3 times it starts right back up and it will run for a little while then stall again. From there I then got in to a pattern that if it dose stall that day its going to the stall the whole day not just once but maybe about 3 to 4 times. If it dose not stall for that day I'm golden it runs great. So then I went ahead and replaced the fuel pump and also all the auto shutdown relays. I then drove it for a while and then here come the jokes. The problem is that fro some reason I was in the snow and it did stall and some how it blew out the transfer case because I was in 4 wheel drive but only the front was working (minds well by a pregnant Honda). Great so I then I replaced the transfer case and back to normal. The stalling is happening soon than before now that where in the summer I did notice that it happens when its either worm or wet out side.

From there I decided to replace the crank sensor for the timing issue and also I went and took it to get all the recalls known to man from jeep. Nothing, still stalling. So then I went and I replaced all the O2 sensors and also took a trip to the junk yard and picked up a throttle body, I cleaned the while unit out and then I took mine off and compared. I didnt see any thing out of the ordinary so I replaced mine with the junk yard one and it ran better but still stalling. Ok, so by now I have spent over 4,000 bucks on this car and I got it for 3,000 (witch I knew it needed work but wow). I then went and check all the fuses to see if I could find any thing and nothing then for some reason my windows stop working and my power mirrors would not work. So then I went back and check them again and nothing so I went back to the junk yard and got a new door panel and the control modular for the drive side. I needed a door panel because it came off and would not shut right and it would leave my dome lights on when I'm driving so I got mad and tore it off. BIG mistake because you cant find thou any where and when you do your gona pay 80 bucks like I did. Any hoot replaced the whole panel and it was working just fin again. Back to my stalling problem I then was reading about this fix, I was like yay!!! So I back out the screws and replaced them with shorter ones and also got plastic screws for the body to make sure there is no grounding and I also made a plastic back side for my computer to make sure it was not getting any kind of short Im not gone lie it worked for a while fro about a month and then back to the jokes, it stalls.

So after all that, I decided to do the whole swap out of the ECU computer. I went threw this place, http://store.allcomputerresources.com/index.html I was reading that you need to make sure its a remanufactured unit not a refurbished on because there going to do the same thing in a matter of time. I also like them because its a life time warranty so if this fixes the problem and it happens down the road all I got to do is send it in. Also these cars are not Hondas you have to order one of these babies because you have to have your mileage and also your VIN number has to be burned in the computer you just cant go to the junk yard and pick one out of an other car and expect it to work. If you do that your going to risk of setting off the anti theft system and ill tell you thats no good. Thats not even a joke it pure hell. So I order mine for about 324.00 bucks with 2 day air and I should be getting it on Friday.

I will check back when I install it and let you people know who have tried every thing in the books. For some reason after all my research a lot of the forms dont tell you that getting a new Computer fixes the problem. So thats why I'm writing this so then you can get a good fix other then that screw business. Well I hope this helps a little bit and what I have tried. If this dose not work I'm going to tackle the wiring harness and the after that I'm going to light it on fire and push it off a cliff. I hope this helps some people.

Before you go changing all kinds of sensors, pick up some heavy duty 24" zip ties. Clean the inside of the pins and the contacts on the PCM with DeOxit G5. As npgreek has stated, wrap the zipties around the back of the PCM and cross vertically over the connectors and cinch down tight. You'll notice the connectors no longer move in the sockets. PROBLEM SOLVED!

I recently replaced the IAC motor as it seemed to stall when I took my foot off the gas sometimes. That mode of stalling has stopped. I also replaced the coil because it would die will cruising for a few seconds and the PCM code said there was a problem with it. That problem has not returned. I still do the "wiggle" and I know the PCM connections are flaky. Allied Electronics sells a burnisher specifically designed for sockets like the type used in the PCM plugs. It has 20 mil rods that will fit inside the contacts and give them a good polish. For the PCM pins, I'm using a plate-maker's eraser. It's like a typewriter eraser. You sharpen it like a pencil and you have a pointy, abrasive tool that you and polish the pins with. I'm also going to try the big, honkin ty-wrap on my PCM and see how that performs. Thanks for sharing your experiences with the rest of us frustrated drivers.

I am having similar issues with my JC Laredo and came across this page. Any thoughts or ideas ? I have read most of these threads and seems like it could be a couple of things. Has 205,000 miles. Runs great besides the stalling issues.

Jeep is stalling out when you let of gas (stop signs,etc.). Starts up again no problem. Brought it in 2 weeks ago. They cleaned out the Idle Air Control Motor and Upper Engine. Solved the problem for about a week or so and now it is back. First it was sputtering at stops, but now it is completely stalling out. Anyone with similar issues have a fix or ideas??