Nick Marlow

Hey guys,
I need some help figuring this one out....

I bought my Jeep in 2015 with all the service records since it was purchased in 2001. Its been solid, but the last year or so its been presenting with a problem that has baffled me and my technician. I have dumped around $1500.00 into it trying to solve this problem and I get closer, but ultimately can't fix the issue.

So, here is this issue: it runs good for long periods of time driving around, but after it warms up (say 30mi of non-stop driving like running errands) it will stall while idling for long periods ( Like running errands and then hooking the trailer up to go too the dump and die while waiting in the line). And it doesn't start right back up, it has to sit for 5 to 10min before it will fire back up and when it does, it runs rough for the first couple miles.
If any of you have an idea of what this might be, please let me know.

I will point out a lot of the parts regarding the idle and throttle have been replaced and it has a new crank sensor and radiator.

Thanks,
Nick

jordan96xj

Your first step will be determine which critical item is falling out when it stalls:

1. Fuel
2. Spark
3. Air

This would mean having a fuel pressure gauge hooked up to the rail, as well as a noid light or test lamp indicating that injectors are getting pulse commands. Then spark tester of some sort (I prefer a no-touch capacitance style spark tester so that I don't have to disconnect wires to test - they can be bought at auto parts stores).

If you have a coil pack, you may need to adjust your spark test strategy.

Then get it warm as usual and pull it into the driveway and cross fingers that it will stall while you are monitoring those things carefully. You are going to need to determine fuel, spark, or air otherwise you don't have direction to go and will only fire more parts cannon rounds at it.

If fuel pressure, injector pulse, and spark remain present, then the throttle body and IAC remain in-play as possibilities.

Things that can fall out when things get warm:
1. General electrical, wiring, harness, and ground connection problems.
2. Crankshaft and Camshaft position sensors or circuits
3. Fuel pump (this is why you watch a pressure gauge)
4. Computer (PCM) (this is why you watch the fuel injectors and spark).
5. Idle Air Control (if it fails when hot, you can get stalls at idle)

Try to get to step one. Fuel, spark, or air.