My jeep has a problem and everybody I have talked to has no idea what could be wrong. Ill be out wheeling and it will be running fine and then all of a sudden it will just shut off. The engine turns over but it will not start. After waiting for about 30-45 minutes it will start right up and run the rest of the time. Ive disconnected my battery and that doesnt do anything. Always has plenty of oil. It only does it when I'm running it off road.

 

When you're offroading, your engine/tranny are getting a little more toasty than normal I would imagine. Which in turn is heating up your Crankshaft Sensor. Normally a healthy Crankshaft Sensor can withstand these hotter temps. However a failing one can not. The reason it cranks over after waiting 30 - 45mins, is because the CPS has cooled down. Also, they don't always throw an engine light.

I'm calling failing Crankshaft Position Sensor. If not... Don't know what else to tell you. There's nothing else that comes to mind that would suddenly shut your engine off.

 

How about the coil? When a bad one heats up it can kill the engine, and start back up after it cools. Had it happen to me, test the coil, easy and free.

 

my '94 used to do this, took me forever to figure it out. it would stall out only when i was offroading it, and crank but not start back up for about 10 minutes. one day i popped the hood with the engine running and grabbed the engine wiring harness with my hand and shook the hell out of it, and whaddya know it stalled. closer inspection revealed that the ground strap that runs from the firewall to one of the valve cover bolts had rubbed against the injector wiring harness and exposed a wire. i took a jumper wire from ground and touched it to the exposed wire and sure enough it stalled out and wouldnt start back up for 10 minutes.
repaired the harness and was good ever since. check that out first, if you dont find anything wrong there, it will more than likely be the crank sensor; when coils go bad they will almost always cause the engine to start misfiring badly to the point where it may shut off; but it wont simply cut the engine right out as if the key was turned off.

 

Where can I have the coil tested? Could I take it to Auto Zone or something?

 

Mine does it to but I think its fuel related. Idk

 

This^

 

Wow! thought i was the only one w/this problem!
https://www.cherokeeforum.com/f2/jee...d-only-139380/

i was getting no spark after it died.. then 25 mins later it ran perfect. i replaced the cps. havent had a chance to wheel and test yet.

 

Until your CPS goes completely dead, which it will eventually do. It will throw completely random symptoms. Most related to the engine just "shutting off". It may not do it for a few days, then suddenly you'll get a no start. Or you'll be driving it fine for hours, shut it off, then try to turn the ignition and nothing will happen.

 

My az wouldn't, but you just use a multimeter.