Tompop

Hi folks.
I have a 1994 Grand Cherokee 5.2. While driving, my Jeep occasionally just stalls. When I try to restart it, the motor just cranks, but doesn't start. If I disconnect the battery for a few seconds, and reconnect it, the headlights and tail lights start flashing. I then put the key in the passenger door an lock, unlock, and the lights quit flashing. The motor then starts without any difficulty. I've heard the flashing lights indicate the factory security system. It seems that by disconnecting the battery, it's resetting the computer. At least that's what I think it's doing. Also, when I drive with air conditioner for awhile, then shutting off the engine for a little while, when I start the engine again, it runs very rough until I start to drive, then it smooths out. While driving with the AC on, it runs fine. It's just after the engine has been turned off for awhile. It doesn't happen every time though. Does anybody have any suggestions or ideas? Thank you ahead of time for any help.

Bustedback

You could have a cam or crank sensor problem, or it might be a fuel problem. When it stalls you need to check for spark. Easiest way to check would be with some starting fluid. When the engine stalls just spray a short burst into the intake and the try and start the engine. If nothing happens you have a spark problem. If it starts, or tries to start, you have a fuel problem.

Tompop

Thanks. I'll give it a try.

Tompop

If I determine between a spark problem, or a fuel problem, where do I go from there? It seems spuratic. And it seems to be getting worse.

Bustedback

Let us know what you find and we'll go from there.

blueseasons

I have been chasing this demon for over a week in a post on this site( The old girls finally crapped out on us) . Mine is a 2000, 4.7. Does the PCM also control the fuel pump? Mine won't start at all now. I've used some starter fluid on it and it does fire. Doesn't run, but I can tell I am getting spark. I cannot hear the fuel pump when I turn the key. Does that mean the pump isn't working because it failed, or because the PCM isn't running the fuel pump?

Bustedback

I would suspect the pump being bad before blaming the PCM. The fuel we are forced to use today is not good for the fuel pump. The alcohol in the gas destroys the pump.

blueseasons

Well I am giving up. I am more easily intimidated at this point. Its been a week and there are to many variables for me at this point. I am having it towed to another mechanic this morning. I'll check back and let you know what they come up with.

blueseasons

Tompop: What did you find out?

Tompop

I ordered a PCM. It should be here next week. Once I get it changed out, I'll post if it did the trick or not.

blueseasons

Where did you buy yours from? After looking on line and researching the suppliers, I opted to go to the dealer for mine. The other places just seemed to unreliable, mostly based on their customer feedback on YELP and even the BBB's from the area they are located.

VTJeep

Yipes.. Dealer prices.. How much did they want for it? I found a place outta Florida that has been excellent. Called em, gave them the VIN and 200 bucks later had a refurbed PCM. They even did a return when I had the part for 1 week shy of a year. They just asked why and didn't baulk at handling the swap. Turned out the PCM was still good, it was the ignition coil that was bad.. Of ya want I'll find the company's contact info for ya.

vk1

Can you give me the contact information for the place you got the PCM from?

VTJeep

Will look it up when I get home. I have the old order form in my "Jeep Notes".

vk1

Thank you so much, i have replaced the fuel pump, spark plugs, distributor cap and rotor button, ignition coil, distributor pick up coil, crankshaft position sensor, and nothing has solved this stalling problem.