I have replaced most all of the sensors; crank, map, temp, throttle position sensor, and I have put in a new fuel pump. The truck will run when it is cold, but shuts down when it warms up during driving.

 

When the truck dies, check to see if you're missing spark. If you are, it is likely the coil acting up.

In addition, you can download the factory '96 service manual from the DIY/FAQ section and look up the procedure for testing the ignition coil. Or since you like throwing parts at problems instead of diagnosing, you can buy one for like $30 or so.

 

The previous owner put the new parts on before I bought it. Diagnosing is what I'm trying to do now. So if it isn't getting spark it might be the pick-up coil? If it is getting spark, do you think it would be the computer? And will the truck have a flash code for a bad ECM?

 

Ahh I see, sorry for the assumption. And no, not pickup coil..IGNITION coil.

It's a possibility that the PCM is at fault, but the only way to know is by eliminating everything else. And no the truck won't always set a code.

 

Ok, thanks for the help!

 

Looked at truck, it has a new ignition coil on on it. It seems like the only thing left that's not new is the computer. With all the new parts is it possible that the PCM needs reset?

 

Okay, having had troubles with these PCMs and helped others through it, here's what to do!

Unhook NEGATIVE battery cable, with it OFF, take your key and turn the ignition to the RUN position, wait 30 seconds, turn it and HOLD it in the START position for 30 seconds, then back to RUN for 30 seconds, then switch it off. Now hook up the negative battery cable again, but do NOT start the engine, and make sure the key is in LOCK position! This will reset the PCM and ABS module, and ALL codes in the PCM. It will cause it to relearn the sensors.

Next, verify that there is a ground wire running from the firewall above the PCM, it will run to the back of the right cylinder head. Is it tightly secured and free of grease? Check this before turning the key to any other position besides LOCK, a bad ground there CAN affect PCM operation. Also check ALL other ground wires you can, a bad ground wire can act up when it warms up, especially if it is one attached to the engine, and a bad ground on a seemingly unrelated circuit can knock the PCM out from doing it's job as it has to share the ground with the other circuit now.

And finally, a PCM failure will NOT always set a code, and many times a PCM setting a code indicating internal failure just needs to be reset properly. The only accurate way to know if a PCM is failing is to have it bench tested, but very few places can do that.

Next step, can you get a OBD1 scan tool, and hook it up to the PCM? Connector is on the firewall on the main harness, not all codes turn on the CEL, or have a code that can be read through the CEL. Write down the CODE NUMBERS for any codes, then post back the results.

Also, to verify it isn't a harness problem, when the engine dies, wiggle the harness good, and try to start it again.

Now once again, have you checked to make sure it gets a spark when it turns off? You MUST do this, otherwise the problem cannot be accurately diagnosed.

Also, though it might seem unrelated, swap the ASD relay with a similar known good relay, and try starting it.

Post back the results.

 

There is a '95 FSM in the FAQ section in addition to the '96 and other model years. The 95 has many peculiarity that are specific to it.

I would definitely check to see if it is a spark or fuel issue once it stalls. What is the temperature doing? Is it rising to a certain point and then stalling or is it running for any amount of time after getting up to temperature and holding there.

Also, has the plenum been fixed? A big enough vacuum leak would cause problems.

 

Also, just curious, did it do this BEFORE you bought it, or why were all those parts thrown at it?

 

It was doing it before I bought it. It has a total of about 1,500$ in new parts, and new tires. I bought it for 600$ because the guy was tired of messing with it and needed money at the time. So if it doesn't take alot to fix it I will be happy.