91 Lumina ECM issue

dera · 11-04-2006, 10:09 PM

I have a 91 Lumina (sedan, not the truck). Suddenly, it would not stay turned over. Took it to an auto repair location, that diagnosed a burned out throttle control. OK. Fixed that.

While they were running it for around 1/2 hour, it did it again. Burned out the throttle control. Running diagnostics after replacing it again resulted in a code stating the ECM was bad.

OK. Replaced the ECM. Still won't work. Replaced it again. No go. He took it to a dealer, who diagnosed a bad ECM (That had been replaced twice). Oh, the prom was also replaced each time. Auto place declines to have dealership fix it.

So, auto place tells me they can't do anything more. They don't know what to do. Now, it is over at the dealership. I suspect an electrical issue, but this is really perplexing. The auto repair place did run the electrical, and couldn't find a fault. But still, why would it show a bad ECM after replacement?

Any ideas???

MT-2500 · 11-04-2006, 10:37 PM

Quote:

Originally Posted by dera

I have a 91 Lumina (sedan, not the truck). Suddenly, it would not stay turned over. Took it to an auto repair location, that diagnosed a burned out throttle control. OK. Fixed that.

While they were running it for around 1/2 hour, it did it again. Burned out the throttle control. Running diagnostics after replacing it again resulted in a code stating the ECM was bad.

OK. Replaced the ECM. Still won't work. Replaced it again. No go. He took it to a dealer, who diagnosed a bad ECM (That had been replaced twice). Oh, the prom was also replaced each time. Auto place declines to have dealership fix it.

So, auto place tells me they can't do anything more. They don't know what to do. Now, it is over at the dealership. I suspect an electrical issue, but this is really perplexing. The auto repair place did run the electrical, and couldn't find a fault. But still, why would it show a bad ECM after replacement?

Any ideas???

Kinda strange but strange things do happen.
A shorted wiring or sensor could short out PCM.
What was the code no?
How did or what made them figure out bad PCM?

If it is at the dealer and if you are going to get them to fix it.
Here is what to ask for.
Tip on going to the dealer
Ask that only a factory certified gasoline engine performance specialist work on your car.
Not all dealerships are concerned with how repairs are dispatched, and not all dealership techs bother to take advantage of the training offered by factory (the vast majority of which is paid training). If the dealer is uncooperative, ask for your money back and call around for a dealer that will accommodate you.

Good luck and let us know how it goes.

dera · 11-15-2006, 04:05 PM

Quote:

Originally Posted by dera

I have a 91 Lumina (sedan, not the truck). Suddenly, it would not stay turned over. Took it to an auto repair location, that diagnosed a burned out throttle control. OK. Fixed that.

While they were running it for around 1/2 hour, it did it again. Burned out the throttle control. Running diagnostics after replacing it again resulted in a code stating the ECM was bad.

OK. Replaced the ECM. Still won't work. Replaced it again. No go. He took it to a dealer, who diagnosed a bad ECM (That had been replaced twice). Oh, the prom was also replaced each time. Auto place declines to have dealership fix it.

So, auto place tells me they can't do anything more. They don't know what to do. Now, it is over at the dealership. I suspect an electrical issue, but this is really perplexing. The auto repair place did run the electrical, and couldn't find a fault. But still, why would it show a bad ECM after replacement?

Any ideas???

Update: The ECM was bad, due to a shorting fuel injector. Replaced the ECM, replaced the injectors. Idles fine now, but anytime it goes over 20 mph, it sputters, misfires, and dies... :-(

MT-2500 · 11-15-2006, 04:59 PM

Quote:

Originally Posted by dera

Update: The ECM was bad, due to a shorting fuel injector. Replaced the ECM, replaced the injectors. Idles fine now, but anytime it goes over 20 mph, it sputters, misfires, and dies... :-(

Oh my.
Well sounds like back to the drawing board.
Do you have any codes now.
Check engine lights?
Does it have good hot blue spark to all plugs.
What engine?
Are you going to DIY it or take it back to dealer to check it out?

twistedtech · 11-15-2006, 05:12 PM

First thing I would be looking for is a bad ground.I ran into this years ago to many that a bad ground would burn out the shifter cable on the older Camaro's.Grounds=Batt to body,body to frame,engine to frame.Just a guess from just a guy.

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