A buddy of mine had an old Pontiac Sunbird 3.1V6 that was doing the same thing, ran until it was warmed up then would die and not start again until it was cooled off. Turned out to be the tourqe converter solenoid. Is that a possibility here? Tomorrow I am going to try replacing the crank sensor, and check the ASD relay wiring. But if that doesn't fix it I am wondering what's next to try...

 

Ignition coil could also be a possibility.

 

Alright so I tried all the "its usually this..." stuff.

-Ignition Coil
-Crank position sensor
-TPS, MAP, IACV.
-Pick-up coil (signal generator) inside the distributor
-Cap and rotor were both burned and corroded so I replaced those. Truck runs better, but still dies.
-checked the ASD wires the solders are solid.

Now what? I determined that she is losing spark when she dies, not fuel. Meaning this is an electrical problem. The computer has a label on it that says Mopar remanufactured so I think it has probably already been replaced at some point. Where to go from here? I am extremely frustrated at this point.

 

You checked/changed the ignition wires? We had a issue with a coil wire once that had a break inside the cover, it warmed up and the wires separated and we lost spark. If you can test the wires for resistance while bending it or have the truck running and flex the ignition/spark plug wires. If its electrical, it could be one of those smaller wires running to and from the coils and distributor.

 

Okay so whatever is causing the ignition coil to lose spark at a certain temperature, I was able to bypass it by running a small wire from the + terminal on the battery directly to the grean/orange wire on the coil. Its a temporary fix only though, so I still need ideas where to look for the open circuit in my wiring harness.

 

Fuel pump pressure? Neighbor had that problem, and it wasn't actually the pump, but the short piece of rubber hose inside the tank that had a slit in it. Gas was being pumped right back into the tank....he spent a lot of money chasing that.
If you do go in that direction, pull the bed for easier access to the tank rather than drop the tank....

 

I'll add one to the list... Nobody has mentioned the ECT (engine coolant temp) sensor yet. There are two on these trucks. One has one wire, and is the sending unit for the gauge. The other has two wires and is the sensor for the computer. The one in question would be the two wire sensor. Since the problem is temperature related, it could very well be a temperature sensor.

Actually, the fact that there are two seperate sensors makes them often overlooked because the gauge can read normal while the computer is getting odd readings.

 

So the problem went away when you ran a hot wire to the coil? Sounding more and more like a busted wire. Time for a wiring diagram and a meter.

 

I thought the problem went away by running that wire to the coil. It didn't. Turned out the E.C.M. was bad. Replaced today, and all good.