Questions and Answers

Cherokee Dies When Hot Q. Vince, I have a 1987 Jeep Cherokee, 6 cylinder, 200,000 miles, A/C, P/S that, when it gets warmed up, will stall and not run again until cool. It seems that this stalling processes happens quicker on hot days (above 75° F) and this past winter was not a problem on short (10 mile) trips to and from work).

However, with warmer weather now it stalls pretty quickly. I get warning when this happens. The engine 'stumbles' like someone quickly turning the ignition off then on again. It'll do that a couple of times over say 10 to 15 minutes then gives up altogether until it sits long enough to cool. The three times I had it towed, by the time it got to the service place it restarts and they cannot find the problem.

So, on a past note to you and discussions with parts stores I was advised to replace the ignition control module. I did that but the problem did not go away. It acts the same. In fact, this time I let the car idle in my driveway for 10 to 15 minutes then drove it three blocks to the gas station. After filling the tank the car would not start again until cool (about 30 minutes).

Is it possible that this is a 'feature' to protect the engine from overheating? The gauge does not show an overheating condition but maybe it's overheating anyway. The engine was very hot to the touch but might be anyway, don't know. Just a thought.

Do you have any other ideas? I only mentioned your past advise as an indication of my status with this problem. Please do not feel that I am disappointed with your advise. I am very happy with your quick responses and willingness to help. I think it was a good call and some things need to be addressed in stages. This is one of those things.

Thank you in advance for your help.

A. Thank you for the understanding. In this venue the best I can do is suggest possible causes of a problem based on my knowledge and experience. If I could diagnose and fix cars like this, I would never need to go to work.

To me it still sounds like classic ignition module failure, but since you did replace it, it must be something else or you got a defective module. This is not a feature to prevent overheating damage.

At this point we need to find out what we lose when the engine dies, fuel or spark. I would like to confirm that it is spark we are losing. There was a problem with the Crankshaft Position Sensors in the 1987 and 1988 Cherokees. There were two different CPS kits, depending on transmission.

Automatic Transmission Service Kit:
PN 83-100-066 Crank Position Sensor Patch Harness Crank Position Sensor (CPS)

Manual Transmission Service Kit: PN 83-100-063 Crank Position Sensor Patch Harness Crank Position Sensor (CPS)

A couple of other things to check is the ground wires at the oil dipstick mounting stud and the coil wire routing. The coil wire can chaff on an A/C line and cause a short to ground.

Additional Information provided courtesy of ALLDATA