Wits end 1992 Dodge D150

[tsubaki]

I'm going to need to do like you and smoke suggest, make up a sequence, go through it and write it down in order to describe it correctly.
No tach on the truck.
Swapping the ASD and fuel pump relays did nothing different, nor did replacing them.

This is the way I remember it the very first time we started looking for this problem:
It would crank up and run for a few seconds then shut off. Leaving the ignition on you could hear the arcing in the distributor.
If you unplugged the DIP (cam sensor) the noise would go away. Reconnecting the DIP sensor before turning the ignition off, the engine would not start.
Turning the ignition off and then reconnecting the DIP sensor, the engine would crank up and run for a few seconds then shut off.
The sensor then got replaced but the problem persisted.
Doing this too many times would flood the cylinders.

We then thought the CPS (crank sensor) may need replacing and did so, the problem was still there after replacing it. We did not go through any sequence of tests with it.

Replacing the PCM seemed the next appropriate candidate, after doing so the problem was still there.
Now the aggravation really begins. After sitting a week or so and checking wire connections literally everywhere beneath the hood and dash, the damn thing cranks up and runs fine for a few months.
Then we start this cycle again at least 3 more times but replacing more different parts.

Another PCM is scheduled to be here today, hopefully I'll be able to get together an actual written test sequence.
Amongst doing other things.

Thanks guys! I do appreciate it.