Random Stalling -CPS/TPS/IAC? Details Inside
 

Hey all,

1999 4.0 with ~150k. This problem started a few months ago and has been happening more and more as time goes on. My XJ runs like a dream however when idling it will randomly stall and not want to start for several minutes. When it does stall, the engine tries starting but it does not seem like any gas is going to the engine, then miraculously after waiting it will start and run fine again.

I've read that this might be an issue with the crankshaft position sensor, others have told me TPS or IAC. I am on a limited budget and would prefer to not throw parts at the problem. When the car does stall, no check engine light comes on.

I stalled today at a stop sign and a fellow jeeper came up to me and told me to remove this sensor (picture below), get the jeep started, and let it sit for 5-10 minutes for it to reset. He said he does this with his jeep and it's been two weeks since his last stalled. What sensor is this exactly? I tried the trick with my XJ and it did run fine for a 10 minute drive after previously stalling a few times.

Attachment 189772

Attachment 189773

Any opinions/diagnoses are greatly appreciated.

Thanks all

If I'm not mistaken that's your intake manifold temp sensor. Highly doubtful if has anything to do with your stalling IMO.

I'm putting money on crankshaft position sensor took a dump. But it won't hurt to pull your throttle body and clean it up along with your IAC.

This also what it sounds like to me. I would start by having it checked for any stored codes. Just because the cel didn't come on doesn't mean you don't have any stored codes.