The only other concept I had was that the injectors are partially clogged and the system is over-pressuring which then triggers a fuel cut by the car… But I don’t like this idea because if the injectors were clogged that badly the car would run poorly and if the injector control mod was going into a safety mode it would more than likely trip a CEL.

Regardless I have been adding fuel injector cleaner the last couple of fill-ups. Infact on my way up north yesterday I pulled off the interstate and at the traffic light it started to stumble and did so for about 8-10 seconds. I feathered the throttle to try to save it and this time instead of stalling out it bounced right back like someone had just flipped a switch and all was good. It idled and rev’d fine after that. This lead me to think of an exposed wire or faulty ground that is affected by the engines movement (bucking in this case) But after a careful combing I didn’t see anything that raised a flag and still unsure how heat would affect this.

 

Attached are the procedures for your car.

 

so I pulled my pump and was shocked to see this.



there was a whole lot more corrosion on it when i took it out. a bunch of black stuff. the wire is barely holding on to the receiver. So I figured when the gas return was activated it was dumping warmer gas over this and increasing the resistance until it cut.

I've got a junkyard pulling out the wiring harness and pump on a wrecked 02' so tomorrow I should be all set

 

I have replaced the fuel pump assembly with one out of a junked 02' with 60k on the clock. The wires and connectors looked great.

Since then I have driven through the mountains and gotten it hot and have not had the problem reproduced.

Thank you all for the help in diagnosing this problem

 

Good to hear the problem may have been fixed. Thanks for reporting back.

 

So I have solved the hot stall issue as previously stated. Last night I had this problem happen again.

After driving at night for 35mins I noticed the car started to miss randomly at different intervals. It started to get worse so I pulled off and when I did I got the CEL and the car went into sub 3k limp mode.

Today I went to get the code pulled and the car was no longer in limp mode. The code is P1381 - CYP sensor intermittent voltage signal (what the hell is the CYP sensor? and would this cause the aforementioned issues?)

 

After a little research it seems as though common items that could be at fault are:

Distributor (Mine is new)
Coil (Mine is new)
Alternator (OEM)
CYP sensor (or wires)
PCM (God I hope its not this)

 

CYP = cylinder-position sensor located inside the distributor.

Look for dirty/loose/corroded connections where the wiring harness plugs into the distributor. Then maybe look for crud down inside the distributor. The infamous "red dust" inside the distributor from a bad bearing can foul up that magnetic sensor.

edit...
So your distributor is new, so I wouldn't expect a bad bearing or messed-up sensor. So look at the wiring harness connections. I think the signal wires for that sensor are shielded, so be careful if you try to cut or splice the wiring.

 

Thanks Jim I'll dive into it here in a bit

 

I just looked back to see you have F23A4 ULEV engine. How "new" is the distributor? Did you get one for the non-ULEV F23A1 engine? (I'm not even sure if the distributor is different)