Quote Originally Posted by steveo View Post
i'd say it would have to be a decent amount of noise to cause issues, the ecm does have some half-decent filtering of its own.

i developed eehack from start to finish with a crappy switching 1 amp wall wart (i think it used to power a cordless telephone or something). i wouldn't doubt if it had a single electrolytic cap with hot glue on it inside. for a lot of the time the wires were just twisted and taped together too. NEVER had an issue, and i reflashed that particular ECM many hundreds of times.

its usually when you put these things in cars with 20+ year old wiring that you have issues.. and it's not good wiring at all.. GM used the thinnest gauge possible.

another possibility is your ECM's VPP circuity is shot. this might be the first time it's ever been used. these are really old ECMs and were never intended for this length of service.
probably i need to review the wirings this night and test with my workstation laptop to see if changes anything...
i just tested with the CAP on the circuit and same result...
i´m also trying to see if i can get another ECM with this same number to do some tests but its kind of hard right now here in town...
do you know what pin would be "responsible" for the VPP? probably i will have to open this up to see if i can find anything visually damage.