Low idle, occasionally stalls until I floor it in neutral and it comes back now. ( didnt used to) Mainly stalls at low RPMs...but lately I have noticed it did it's ...( stupid thing it does, with sputtering, sometimes backfiring etc)...after I go over some bumpy terrain, which is not often. ( heavy side to side motion).
It's not predictable. Sometimes it will cut out once or twice at higher RPMs like maybe 2K. I thought it was bad gas...so I dried it with alcohol. I thought the side to side motion ( rocking) caused crap in the gas tank to clog the lifetime fuel filter.
NEW:
Battery ( cleaned posts and cables to a shine too)
TPS ( mine broke)
IAC ( no change after cleaning throttle body, so I put the factory one back on)
CPS- MOPAR.
PLUGS
ROTOR cap
Wires ( last summer)
Dist. Cap ( last summer, but I have a new one to install tonight)
Just installed a new pick up coil ( cam pos sensor). Havent driven it yet. But it started fine and idled OK. This is not uncommon.
Wiggled CPS wires and harness while idling today. No change.
Bought new primary coil, havent installed it.
Fuel pressure at rail is fine.
Codes, as they were printed out today before swapping cam sensor:
PO320
Ignition/dist
Engine Speed Input
Circuit malfunction
PO351
Ignition Coil A
Primary/Secondary
Circuit Malfunction
Plugs to PCM wiggled while running...no change.
New Cat convertor last summer.
When it idles ....SOMETIMES it has a slight, almost unnoticable miss. It's random , not at regular intervals.
Rear main seal leaks, so I noticed oil on the Crank Pos sensor that I replaced. Beginning to wonder if that's the culprit.
And yes, I know about the screw length on the PCM cover.
Anyone have an idea?
Thanks in advance.
Reply 1 : 97 Jeep Grand Cherokee stalling not fixed yet...
Connections look fine.
Also....something occurred to me about this ....the stalling started right after I lost power window functions at driver's door. Replaced module on drivers door..no change. Looked for bad/broken wires in door jam...all seem ok...even after splitting boot. Bad ground somewhere in window circuit causing glitches in PCM ? Battery ground to body OK. Cant seem to find engine ground to body...although I know it's supposed to be on firewall.
Reply 2 : 97 Jeep Grand Cherokee stalling not fixed yet...
Reply 3 : 97 Jeep Grand Cherokee stalling not fixed yet...
Update: Found a ground point on the engine block, passenger side near the rear. Decided to put a wrench on it....and it turned pretty easily.
Took the nut off and the wire that came from the harness....sprayed the contact points with contact cleaner, wiped them, and reinstalled the nut tightly. Two days now and no sputtering, although it still idles low.
Will look for vacuum leaks today. But maybe the main stalling problem is fixed. Keep your fingers crossed.
Reply 4 : 97 Jeep Grand Cherokee stalling not fixed yet...
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?
Reply 5 : 97 Jeep Grand Cherokee stalling not fixed yet...
Did the power window problems and the stalling problem start at the same time?
Do the power windows work from the controls on the passenger and other doors?
Have you checked the voltage to the coil from the PCM?
When you say rough terrain, are puddles of water involved?
Does rocking of the vehicle seem to cause it? (if it is running fine, could you get it to mess up by rocking the vehicle side to side or front to back)
Can you smell gas in the exhaust? I doubt it, but it's worth a sniff.
BTW, you probably know this, but it's usually not a good idea to clear the codes by disconnecting the battery. The PCM loses the stored information that should help it run better.(not always the case)
Reply 6 : 97 Jeep Grand Cherokee stalling not fixed yet...
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.
Reply 7 : 97 Jeep Grand Cherokee stalling not fixed yet...
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Reply 9 : 97 Jeep Grand Cherokee stalling not fixed yet...
My tach still wobbles a bit ( about 25 RPM or so) at near idle speeds, so I'm guessing it isnt fixed yet.
Still searching for the engine to body ground strap. If anyone knows exactly where it is, please advise. It's supposed to be on the back of the head or block, and attached to the firewall. Havent found it yet.
Reply 10 : 97 Jeep Grand Cherokee stalling not fixed yet...
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.
Reply 11 : 97 Jeep Grand Cherokee stalling not fixed yet...
It tried to stall a few times during the 240 miles I have put on it since the last work was performed.
Last nite, out of nowhere, it acted stupid again. Arrgh ! It was drizzling rain and cold. The rain has never been a problem before. I pulled over, let it idle ( after restarting it once again) and wiggled the plugs on the ECU cover.
It died. I thought it was a fluke, so I started it once again. It was running a bit rough, so again I wiggled the plugs. It would clear up and then die. Restarted it again and let it idle. Watched it without touching anything for a minute. Then I wiggled them again, particularly the inboard plug....in all different directions. It would clear up but I couldnt hold it there....then it would act up again. So I got it running again and drove to my girlfriend's condo, where we were heading at the time anyway.
Oh, BTW this is the second time I've put more gas in the tank since the fuel pump. I filled up again at 1/2 a tank.
After about 2 miles.....it really started acting up....stalling, and bucking....and while it was trying to restart it backfired TWICE, loudly....but it restarted. Pulled into her carport...let it idle and it was fine. Came back out, started it and wiggled the inboard ECU plug.
NO CHANGE. It ran pefectly. I left her place at 4 AM and it did OK all the way home...( about a 10 minute drive).
I noticed that there is a little plastic piece that came off the ECU plugs when I pulled them earlier in the week. No way to put them back in. They lie on top of the plug somehow.
Today, I'll pull them again, spray with contact cleaner and see what happens.
Should I put dielectric grease on them or not? There was no sign of any grease ever being on them when I pulled them the last time.
I'm getting close....but still no cigar. I could be buying gas with water in it and not know it. That would really tick me off.----
Another update: I start the jeep today....wiggle the ECU connectors and every wire I can find...and I cant MAKE it stall now.
This is driving me nuts !
Reply 12 : 97 Jeep Grand Cherokee stalling not fixed yet...
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?
Reply 13 : 97 Jeep Grand Cherokee stalling not fixed yet...
Anyway, if you can, get a new connector and wire it up. Or you could connect the plug more securely. It more than likely just loose because the clamps broke off.
Reply 14 : 97 Jeep Grand Cherokee stalling not fixed yet...
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
Reply 15 : 97 Jeep Grand Cherokee stalling not fixed yet...
What I meant was the digital circuits in the ECU not the PCM. I would check for continuity and shorts between the two wires from the Crankshaft sensor to the ECU, set at the lowest Ohms with the wires disconnected from both the ECU and the Sensor.
Reply 16 : 97 Jeep Grand Cherokee stalling not fixed yet...
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.
Reply 17 : 97 Jeep Grand Cherokee stalling not fixed yet...
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Reply 21 : 97 Jeep Grand Cherokee stalling not fixed yet...
I suggest changing your MAP sensor and/or crank position sensor. The MAP is easier to replace (5 minutes, literally), the crank sensor is tough to get to but only one bolt. Throttle position sensor is a player too, but I see you replaced that.
Also, after changing sensors, the PCM might freak out and the engine runs like garbage for a minute or two as everything "settles." But that behavoir should not continue once the PCM "learns." Scary.
Good luck.
Reply 22 : 97 Jeep Grand Cherokee stalling not fixed yet...
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.
Reply 23 : 97 Jeep Grand Cherokee stalling not fixed yet...
Refer to my other posts about this Jeep...for the history.
It was the blasted plugs on the PCM !
I had unplugged the 3 wiring harness plugs and sprayed the crap out of them with contact cleaner before...with minimal results.
But on a hunch and some advice from an old Jeep Mechanic...I took some zip ties and put 2 on each plug....running them around the back of the PCM, vertically. 'Cinched them all down tight with pliers...then put another one across all of them.
Jeep Stalling is fixed ! It's been over 4 months and it hasnt even hicupped once. Evidently the heat and vibration caused them to have an intermittent connection at times....throwing the computer out of whack....thus..the stalling, backfiring, stuttering....and bad timing.
Heck, I may even put some JB weld on those dang computer plugs now !
If I could only get my stupid power window problem nailed down, I'd be happy now. There are 206,500 miles on that 4.0 engine and it still runs great. Hope this helps someone.
Reply 24 : 97 Jeep Grand Cherokee stalling not fixed yet...
Reply 25 : 97 Jeep Grand Cherokee stalling not fixed yet...
Dave in S. Jersey
Reply 26 : 97 Jeep Grand Cherokee stalling not fixed yet...
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Reply 28 : 97 Jeep Grand Cherokee stalling not fixed yet...
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??
Reply 29 : 97 Jeep Grand Cherokee stalling not fixed yet...
Thanks, Again!