1992 Chevy P30

[In-Tech]

Hiya Bob,
Did you make it home ok?

[boba]

Still waiting for the replacement ECU Carl, I'm beginning to think some higher power doesn't want me to get up north this year for some reason.
Maybe all the problems go away if I just turn around and go south?
I dunno either...
It turns out I have enough spare parts with me to build a Speeduino, I've been working on that.

[boba]

So it's finally fixed, did 700+ miles yesterday and today and got the rig and myself home.
Theory as to why this was such a headache - the only real failure found was a bad fuel injector randomly finding ground through the case. (hot or cold, wet or dry, day or night, it didn't matter - it could show up at any time, and just as easily behave normally for a day and fool me into thinking I'd found the problem somewhere else).
My theory as to how that caused PCM failures is that the injector was randomly firing in response to the intermittent ground, building up an inductive voltage, and when a timed ground from the PCM was present it was grounding not only the 12v feed for the injector, but whatever induced voltage the injector had already built up.
Odd that it didn't blow the injector fuse, but two new injectors and an undamaged PCM and the rig ran as good as it ever has and did a few days of driving without a hiccup.

[In-Tech]

Good job.

[boba]

Thanks Carl, it would have been a significantly harder adventure without the interest of the people here, and I do hope it's information that will help someone else should they have this kind of trouble.

[In-Tech]

Yes, it's easy to get super cranky when you don't have anyone else to bounce Ideas off. Glad you got it sorted.
I'd still like to read that stock AWUM to have for my archives. If someone else has a copy, please post :)

[MO LS Noobie]

So glad it's fixed and you made it to your destination. In 45 years of fixing cars I've seen shorted injectors (esp. Multecs) but not one that destroyed PCMs. One to add to what is left of my memory bank.

Jeff