Has anyone replaced the ECM ?
- Thread starter elcotrk
- Start date
- Status
I did years back in my 86 El Camino. I was having issue with getting the dwell set on the carb after rebuilding it, would go dead lean and stall the engine. I managed to find a point where it did run but The "Service Engine Soon" light then went into a state of constant flash without having a code reader installed. Lasted a few days before the car went into full rich limp mode. (Rotten egg smell exhaust, NO power)
A good friend offered a new ECM he had removed from his 86 SS drag car and after install and re adjusting the dwell on the Q-jet it ran problem free for over 200,000 miles.
A good friend offered a new ECM he had removed from his 86 SS drag car and after install and re adjusting the dwell on the Q-jet it ran problem free for over 200,000 miles.
If you drop them from the top of the stairs, it's probably not good for them. For the most part, they're pretty durable parts, believe it or not. If they've been living in high humidity and dunked in water, or been laying out in the boneyard for 15 years or so, all bets are off. But generally speaking, if your car has been driving around for the last 35-40 years, you likely wouldn't have had to mess with it.
The only time you probably would have to change it out is if your diagnostic checks rule out EVERYTHING but the ECM. The CSM kinda uses this as an out, but it's true that if every sensor and wire checks out like it should but still aren't getting the right signals out of the ECM, then replacing the ECM isn't the worst thing in the world. But it should never be the first choice unless it's been under water, or caked with mud, or rusty as heck, or you accidently let the smoke out of it.
It's rare, but an ECM failure can happen. 99% of the time, it's a sensor or bad vacuum hoses or mucked up/loose/broken wiring.
The only time you probably would have to change it out is if your diagnostic checks rule out EVERYTHING but the ECM. The CSM kinda uses this as an out, but it's true that if every sensor and wire checks out like it should but still aren't getting the right signals out of the ECM, then replacing the ECM isn't the worst thing in the world. But it should never be the first choice unless it's been under water, or caked with mud, or rusty as heck, or you accidently let the smoke out of it.
It's rare, but an ECM failure can happen. 99% of the time, it's a sensor or bad vacuum hoses or mucked up/loose/broken wiring.
My Mom's 1989 Cutlass Cierra went through a few. Back then it was easy to get a junkyard ECM and swap the OEM chip into that. Her problem was with the AC which the ECM had a role in somehow.
Usually they end up getting removed and replaced with an old school carb or a modern EFI system. Cars of our vitage don't need them in the fine state of NY to pas inspection, so when problems arise - out they go.
Probably at some point I'll wish I had the saved the ones that I've thrown away.
Probably at some point I'll wish I had the saved the ones that I've thrown away.
GM service manual checking TPS, sensor and wiring OK. Still High voltage 417 blue wire, manual says everything checks out replace ECM, burns rich won’t idle guzzles gas
That’s why I think it would be rare it would go bad
Getting a remanufactured or used is a concern
The worst part is you're probably correct.Soon they'll be worth...
I have a an original ECM and MAF ECM for an '85 Vette (one year only).
You couldn't get a new one regardless. Even GM ones were re-manufactured. Now it may have been possible to get a new one within the model year it was being built, but after that, you were getting reman units. Nearly every single one of them. They did that with starters and alternators too. Plus a few other things. They started the reman thing with water pumps later, but mostly they were new, carbs were new, and A.I.R. pumps were new, along with P.S. pumps, master cylinders and brake boosters.
- Status
Similar threads
