No fuel when engine is hot: Fuel pump, ASD, PCM, sensors, heat?

Liberated

TJ Enthusiast
Joined
Aug 23, 2018
Messages
119
Location
Northwest Ohio
Hi guys. I've been searching the service manual, and the forum and haven't been able to get find an answer. Forgive me if this has already been answered somewhere else, because I haven't been able to find it.

When my engine gets hot, and stays that way for several minutes, I lose power to the fuel pump. Engine will turn over all day, but no fuel.

Istill have ground back there, and have checked it good across the fuel sensor power in the same connector, even afrer dying. My fuel pump relay is good. I've attached below a picture of the relay. At one point I found the pinout for the relay(in the fuse block) in the service manual, but now I can't seem to find it again. Once it dies, I have power across 85-86, and 30-87. 87a appears to be open.

78279


Do I understand correctly that if 87 is closed, that the automatic shutdown(asd) is engaged? If that's the case, what kind of sensors or what have you could be bad to engage that? I replaced the CPS about a year and a half ago (along with the tps I think)

I'm hoping it's not the PCM itself, but am tired of chasing this gremlin.

I do what I can and learn as I go, but I don't have a large understanding to start from. Your knowledge would be much appreciated.
 
I had the same issue. 05 Unlimited after driving around my jeep would just die and wouldnt start right up until 40 min or so. I had PCM issues and replaced and I also found my ASD caused the shut down. I swapped the ASD with the horn relay and the engine ran for hours without shutting down. All this after I changed the fuel pump, crank position sensor and cam shaft sensor. Well everything is in working order now.
 
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