91 ZR-1 Cutting Out Under Load

[GregCrowe]

I'm starting to think ECM. Think about this guys. How many times in your lifetime have you messed with a car and then had something start acting up. You always think that the last thing you did to the car could not have possibly caused the problem but sure enough, after driving yourself crazy, you discover that whatever the hell you did caused the problem.

Back in the very beginning of this thread, I said that this problem happened exactly the time after changing the PROM from a Doug Rippie to a newer redesigned GM. Replacing the PROM back to the Rippie made no difference, same cutting out.

The very first thing I asked out here was could screwing around with the PROMs have caused a problem with the ECM. Everyone said no way. I am now guessing that somehow something inside the ECM must have gotten screwed up. I think I will take up the offer from JeffVette to try the spare ECM. At least that way I won't be out any more significant money and I won't have to pull the plenum again.

[LT5-Lee]

Originally Posted by GregCrowe

I'm starting to think ECM. Think about this guys. How many times in your lifetime have you messed with a car and then had something start acting up. You always think that the last thing you did to the car could not have possibly caused the problem but sure enough, after driving yourself crazy, you discover that whatever the hell you did caused the problem.

Back in the very beginning of this thread, I said that this problem happened exactly the time after changing the PROM from a Doug Rippie to a newer redesigned GM. Replacing the PROM back to the Rippie made no difference, same cutting out.

The very first thing I asked out here was could screwing around with the PROMs have caused a problem with the ECM. Everyone said no way. I am now guessing that somehow something inside the ECM must have gotten screwed up. I think I will take up the offer from JeffVette to try the spare ECM. At least that way I won't be out any more significant money and I won't have to pull the plenum again.

These were the classic symptoms in the early days of the first "brain" failures, suffered mainly by Fords. The heat would cause the epoxy "brain buckets" would ooze out like a molasses leak and it was relatively easier to diagnose.

I was doing some time surfing the net for other mass ECM failures and it seems the Mitsubishi guys were hit pretty bad for the same issue. They have traced it down to one common and almost predictable failure, especially in the early '90's involving guess what?... A bad batch of "leaking capacitors"... sound familiar?

Maybe the question should be, why haven't all early ECM's failed like our Bloose amplifiers?

Has anybody noticed any NOS units failure rate to be higher than later rebuilt units or have any data of when GM's manufacturing runs of ECM's have held up better?

Lee

[jonszr1]

i could be nuts but it sure sounds like coils ,when cold they are fine but once they start to get hot they break down. i have had this happen in ca couple of my carbed cars. also if you werent carefully putting the prom back in you might have bent atang or loosened the solder connection on a tang . just a couple of thoughts i had . stick with the guys they will help you till you find it . they hate seeing a zr1er not being able to drive their ride

[GregCrowe]

Originally Posted by jonszr1

i could be nuts but it sure sounds like coils ,when cold they are fine but once they start to get hot they break down. i have had this happen in ca couple of my carbed cars. also if you werent carefully putting the prom back in you might have bent atang or loosened the solder connection on a tang . just a couple of thoughts i had . stick with the guys they will help you till you find it . they hate seeing a zr1er not being able to drive their ride

I think we're on the right track. I'll try the spare ECM first since it's a cheap test and if that doesn't fix it I'll pull the plenum once again and replace the coils.

If this thing ever gets fixed it really should run great, everything is freaking new.

Also........ yes, very very familiar with the Mitsubishi capacitor leakage. All Eclipses and 3000GT's have this failure from like 93-99.

[Zr1 Destroyer]

coils.....

[LT5-Lee]

Originally Posted by GregCrowe

I think we're on the right track. I'll try the spare ECM first since it's a cheap test and if that doesn't fix it I'll pull the plenum once again and replace the coils.

If this thing ever gets fixed it really should run great, everything is freaking new.

Also........ yes, very very familiar with the Mitsubishi capacitor leakage. All Eclipses and 3000GT's have this failure from like 93-99.

Gregg, if it's not, I want your car to sell to my brother-in-law.

I am almost in OK. pretty regularly (Texoma). How would you feel about some trading?....

Lee

[GregCrowe]

Originally Posted by LT5-Lee

Gregg, if it's not, I want your car to sell to my brother-in-law.

I am almost in OK. pretty regularly (Texoma). How would you feel about some trading?....

Lee

Ahhhh, I'll get it fixed eventually. It may take 10 years but I'll get it fixed.

[GregCrowe]

I'd like to take a moment to throw out a public THANK YOU to JeffVette who is at this moment sending me a ZR1 ECM to try. Thanks Jeff, much appreciated. I'll report back when I give the ECM a shot.

[LT5-Lee]

Originally Posted by GregCrowe

Ahhhh, I'll get it fixed eventually. It may take 10 years but I'll get it fixed.

I don't blame you. If it is a ECM, I sure would be curious if the problem was a few bad capacitors that puked out their guts?

Originally Posted by GregCrowe

I'd like to take a moment to throw out a public THANK YOU to JeffVette who is at this moment sending me a ZR1 ECM to try. Thanks Jeff, much appreciated. I'll report back when I give the ECM a shot.

Greg, ECM left today.