1996 Jeep Grand Cherokee 4L stalls

[Jeremy092288]

Ok, I changed my Air Charge temperature sensor and it did not change my scenario at all. However, when my car stalled just recently it reset my computer clock that's beneath the radio and stuff. That's why I am pretty sure it has to be some sort of electrical issue. Check out what I found while searching around the internet.

Jeep Grand Cherokee stalling fixed!

by 1996Jeep GC - 5/18/07 7:44 PM

Found that the outboard PCM cover screw was shorting out the circuit board. Chrysler PCM p/n P56028412, s/n TEH106636023.

Short story long: I have a 96 Grand Cherokee 4.0L, 125,000 miles. Several weeks ago, I started to have stalling issues. Hot or cold, dry or wet, first drive of the day or last, it didn’t matter. The engine would cut out. It felt like it lost all electricals.
At the time it was showing an ASD relay code. Swapped the ASD and A/C relays. Same problem. I didn’t have time to look at it, so I had the dealer go through it. After 2 days and $200, they called and said it was the ASD relay, and that they put in a new one, and it’s all good. Um, ok, maybe I missed something. I’m a trusting soul, but let’s see if this fixes it. The next day the problem was back. I went back to the dealer and they basically said, “We don’t know what it could be, good luck with that”. Now my wife knows why I don’t go to the dealer. By the way, the old relay tested good.
My turn. Being the methodical aircraft mechanic that I am, I grabbed a multi-meter, contact cleaner, and wiring diagrams. I cleaned connectors, ohmed out wires and sensors, checked for power and grounds. Everything checked good. By now, it’s showing ASD, crank sensor, and primary ignition codes. Then, with my wife trying to start it, I wiggled the connectors on the PCM. Every time I wiggled the gray C3 connector just right it would run. When I let go, it would die. So I took the connectors apart and tightened up the crimps (I don’t recommend doing this without the proper extractors and crimper). Threw it back together and BAM! Same problem. Well, time to bite the bullet and check for bad solder joints on the PCM board. I took the cover off of the PCM and realized that looking through the potting compound is like looking through Guinness Stout. But, I put it back in and hooked it up. It started stronger than ever, and didn’t even think about stalling. Yes! I figured that I finally got the connectors sorted out, so I left it over night to cool down. Got up the next morning and it started right up and wouldn’t stall even when wiggling the connectors. So I put the cover back on, put the PCM back in, hooked up the connectors, and BAM! It wouldn’t start! That was the point when my wife asked, “How’s it going?” And I, being the methodical aircraft mechanic that I am, said, “what the ----?” That’s when my wife turned around and went back into the house. While smoking a pack of cigarettes, I thought, “Gee, it runs with the cover off, but not with it on.” DUH, wonder what it could be? So I backed out the two screws that hold the cover on and BAM! It started right up. Then, while it was running, I tightened the outboard screw and sure enough, it died. Yes! Aircraft mechanics love it when they can make things stop working. I installed new screws (1/4” long, factory screws are 1/2” long Torx head), and she’s been running great ever since.
Now, will this fix a bad crank sensor or idle air motor? No. But it is an easy trick to try before going to the dealer and having them throw expensive parts at your Jeep and seeing if any of them stick. Just back out the cover screws about 1/8”-1/4” (don’t worry, nothing will fall apart inside). If it fixes it, great! Spread the word. If not, use logical trouble-shooting steps. Learn the systems – what will and what won’t cause the problem. Good luck.
As a side note, if you want to see a service manager’s eyes pop out of his head, tell him that you want your money back because your not going to pay them to trouble-shoot a design defect. It’s a glorious sight.

My Jeep is unavailable for a picture right now, but it's easy to find.
It's located in the engine compartment on the passenger side of the firewall, aft of the coolant reservoir. You will have to remove the reservoir. The PCM is a square metal box mounted vertically to the firewall with three bolts. On the front, you will find three large rectangular connectors, one black, one white, one gray. Beneath the two outer connectors, you will find the two screws. You do not need to remove the connectors. The screws use a #25 Torx bit for removal. Back the screws out about 1/4" and see if that makes a difference. If you have the same problem I did, install two new 1/4 or 3/8 #6 sheet metal screws and your good to go. If not, come back with detailed info and I'll try to help. Good luck, and let me know what happens.

Here is the link if you want to read it yourself:

http://forums.cnet.com/5208-6035_102...hreadID=248386

[Jeremy092288]

so good

????

Has anyone tried this to see if it works yet?

[Jeremy092288]

FIXED IT!!! I took it to a mechanic who charged me 45 dollars to reground the PCM to the frame. He tightened the bolts really good and she hasn't stalled since!

[Triksr4kds]

Awesome!
So it was the same thing as the article you posted?

[mmilitary]

My girlfriend has a 96 Grand Cherokee Laredo with 107,000 miles on it and when she first bought the car in November, she had the same problem with it stalling out at low speeds. Had it in and out of the shop for a month, before they just put in a new computer. It hasn't had a problem with stalling out since then.

[FirstJeepGC]

Hello all. I am a new member here and I was reading through the forum. It seems like there may be someone out there that could help me. I have a 1996 Jeep Grand Cherokee Laredo 4X4 (4.0L 6cyl.) and while driving the Jeep may jerk a few times, backfire (just recently), and the RPM's drop to zero. I used to have to pull off the road, turn the car off, and it immediately starts back up. Lately, the car does not die while driving, but feels like it's about to. The problem has been intermittent but is becoming more frequent now. The problem occurs when the car is not under any particular load (such as going up a hill) and seems to happen only when the car is at normal operating temperature. I’ve already replaced the PCM, Ignition Coil, Crankshaft Position Sensor (CPS), Manifold Absolute Pressure Sensor (MAP) (CHECK ENGINE light came on for all of the aforementioned), Throttle Position Sensor (TPS), Fuel Filter, Spark Plugs, Wires & Distributor Rotor. The CHECK ENGINE light has not come on since the replacements so I don't think there are any codes to check. My next step is to replace the Distributor & Distributor Cap. Does anyone have any idea on what's going on? Has anyone else experienced these types of symptoms?

Thanks in advance,

[CoachKarl]

Hello FirstJeep,

You've replaced the entire ignition system, so it's not the problem. I'd start checking the fuel.

I'd take a pressure reading off the fuel rail, and if your fuel filter is original, swap that out.

Be sure to post back with your solution.

Karl

[FirstJeepGC]

Originally Posted by CoachKarl

Hello FirstJeep,

You've replaced the entire ignition system, so it's not the problem. I'd start checking the fuel.

I'd take a pressure reading off the fuel rail, and if your fuel filter is original, swap that out.

Be sure to post back with your solution.

Karl

Karl,
Thanks for the advice. I plan on replaing the FUEL PUMP RELAY first, and then hopefully the DISTRIBUTOR, because the CAMSHAFT POSITION SENSOR is located on it. I'm not really comfortable performing the Fuel Pressure Check myself, so I'll see if an auto shop can do it for me (at a reasonable price of course). Thanks again, and I 'll follow up soon.

[95zj-tilshedies]

Originally Posted by FirstJeepGC

Karl,
I plan on replaing the FUEL PUMP RELAY first, and then hopefully the DISTRIBUTOR, because the CAMSHAFT POSITION SENSOR is located on it.

No need to replace the entire distributor if all you want replaced is the camshaft position sensor. Simply buy the new sensor, take off your distributor cap, remove the old sensor and replace...

[FirstJeepGC]

Originally Posted by 95zj-tilshedies

No need to replace the entire distributor if all you want replaced is the camshaft position sensor. Simply buy the new sensor, take off your distributor cap, remove the old sensor and replace...

I thought I would be able to purchase just the Camshaft Position Sensor, but when I search on-line, I can never find just that for a 96' JGC. So I figured I would have to purchase the whole Distributor. The Haynes Repair manual states, "the sensor is located in the distributor and is triggered by a pulse ring". I have yet to look past the Distributor Rotor, so I'll have to lift out the "pulse ring" and look underneath it.

Thanks for the advice

[FirstJeepGC]

Originally Posted by CoachKarl

Hello FirstJeep,

You've replaced the entire ignition system, so it's not the problem. I'd start checking the fuel.

I'd take a pressure reading off the fuel rail, and if your fuel filter is original, swap that out.

Be sure to post back with your solution.

Karl

Well, I had the Fuel Pressure checked yesterday, and was told that it's perfect. It should be between 47PSI to 51PSI, and mine was 52PSI. The PSI's increased properly during acceleration. The pressure was checked after the car sat for 5 hours, and no warmup. As soon as I left the auto shop, the Jeep sputtered, and stalled out about a mile away (pulling into AutoZone). The mechanic suggested changing the PICKUP COIL (circular plate in Distributor). I replaced the Pickup Coil, and the car idled poorly, then wouldn't start at all. I put my old one back on, it still idled poorly, but would start, so I returned the new Pickup Coil, and got my money back. I found a shop that would look at my car today. It sputtered & stalled about one mile from home. I got gas (Exxon), and drove for about 30 miles w/o the slightest hiccup. So of course when I dropped it off at the auto shop, the only way to properly diagnos it, is if the problem occurs w/ them. I'm praying to GOD that stalls w/ them. The problem never occurs when a mechanic has it, which is the biggest pain in the...............
I'll follow up tomorrow....

Thanks

[Mjmorek21]

I had problems with my jeep stalling similar to above posts. A dealer last year even said replace the pcm! I did not. Because was not sure it would fix stalls. Another shop said replace 02 sensors and distributor cap rotor. I replaced the catalytic converter when the check engine light came on. It needed to be replaced my jeep had 262,000 miles on it. The jeep still stalled. I DID NOT WANT TO start replacing sensors relays etc. What finally worked was I replaced the oxygen sensor heater circuit fuse under the hood. It is a 15 amp fuse and it looked bad but was not blown but looked very bad when i took it out. It was so easy after all my stalling infact i replaced all the 15 amp fuses it looked like corrosion on tips. Also with ever fillup I add STP fuel treatment. I AM NOW AT OVER 263,000 MILES and no stalls since I did both of those things.

[golflateron]

Hi guy`s I have a 96 grand Laredo with lots of K`s on it however it has only just started this stalling problem over the last 6 m0nths or so ,I have taken it to mech`s etc and no one seems to know what is wrong,mine actually stalls if I have been driving for a while and then stop say at traffic lights or in a traffic jam , it does not want to drive its as if I have lost all drive however turn off and wait 3 to 5 mins and all is ok for a while !!.also I have been reading the majority of your posts and all mention the cps however I do not have a black box located behind the coolent bottle but I do have a aluminium box on the driver`s side wing between the wing and brake system !!,and also I have tried to remove it and I have found that it has 3screws in the front and 4 on the back so maybe my jeep has been modified also the cover of the box is a wrap around aluminium lid and it looks like it is sealed ! so where do I go from Here can anyone please help , I would also add that the car runs perfectly
the motor is in very good running order and manf date is Feb1996

[rizky17]

I think the jeep is not only tough but it's so cool especially in ride every man will certainly look like a cool Coboy .. I like adventure

[vigiljennier]

Thank you to the person who said to change out all the 15amp fuses under hood. It worked. Yay