1992 ecm
Thread Starter
Heel & Toe
Joined: Jul 2018
Posts: 19
Likes: 2
From: Breezy Point, MN
1992 ecm
I just confirmed today that my ECM is bad. It doesn't appear anyone makes these anymore so looks like rebuild is my best option other than going after market. Not sure if I want to open that can of worms. I found this site that claims to rebuild them ( https://siaelec.com/product/16159278...repair-return/ ). Does anyone have any knowledge or experience with them? Or any advice to my issue?
Team Owner
Joined: Jul 2004
Posts: 28,464
Likes: 3,288
From: Hartford WI
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
I just confirmed today that my ECM is bad. It doesn't appear anyone makes these anymore so looks like rebuild is my best option other than going after market. Not sure if I want to open that can of worms. I found this site that claims to rebuild them ( https://siaelec.com/product/16159278...repair-return/ ). Does anyone have any knowledge or experience with them? Or any advice to my issue?
Thread Starter
Heel & Toe
Joined: Jul 2018
Posts: 19
Likes: 2
From: Breezy Point, MN
GaryInArizona, I've been working on this car a lot since I bought it in 2016. There are getting to be so many new parts that I think it's going to become fairly reliable soon. Anyway, the most recent problem is it started idling high, then went back to normal, then high idle and it eventually stayed so it idles at 2000 rpms now. So I checked for vacuum leaks = none. So I bought an IAC valve and installed = Problem still exists. I've been suspecting the ECM for other issues such as my AC not working now and all the other components of that system are either new and/or working correctly. So I gave up and brought it to a local shop. Their diagnosis is the ECM isn't sending pulses for the IAC valve. They didn't have a tech1 to try and reset it (Relearn), but I doubt that would be the case anyway. Far more likely a resistor or something burned out in the ECM than it just 'forgetting' the IAC setting.
Team Owner
Joined: Jul 2004
Posts: 28,464
Likes: 3,288
From: Hartford WI
GaryInArizona, I've been working on this car a lot since I bought it in 2016. There are getting to be so many new parts that I think it's going to become fairly reliable soon. Anyway, the most recent problem is it started idling high, then went back to normal, then high idle and it eventually stayed so it idles at 2000 rpms now. So I checked for vacuum leaks = none. So I bought an IAC valve and installed = Problem still exists. I've been suspecting the ECM for other issues such as my AC not working now and all the other components of that system are either new and/or working correctly. So I gave up and brought it to a local shop. Their diagnosis is the ECM isn't sending pulses for the IAC valve. They didn't have a tech1 to try and reset it (Relearn), but I doubt that would be the case anyway. Far more likely a resistor or something burned out in the ECM than it just 'forgetting' the IAC setting.
I would scan and see if the ecm is responding properly. Set the minimum air rate using IAC counts and tear out the page in the FSM that tells you how to do it without a scanner.
Thread Starter
Heel & Toe
Joined: Jul 2018
Posts: 19
Likes: 2
From: Breezy Point, MN
I used Propane, then tried brake clean. No vacuum leaks detected that way. I don't know how to scan the ECM to do any of what you're saying. The mechanic told me the ECM wasn't sending pulses to the IAC valve. I don't have an SES light. Either burned out or as indicated in service manual, might be bad ECM. There are some tests I can do for that. Also my AC system won't work and the ECM is the last piece of that system that hasn't been replaced or fixed. It doesn't send current to the relay. If I had more resources and/or knowledge I'd test more thoroughly but evidence so far points to ECM.
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Thread Starter
Heel & Toe
Joined: Jul 2018
Posts: 19
Likes: 2
From: Breezy Point, MN
Thanks Aklim. I have thought about getting an OBD1 scanner for this car. I have a few good OBDII scanners but nothing for OBDI. I might be selling this car though after I get it working properly. My original goal was to get a gen 6 Camaro when my truck got paid off. Truck is paid off next month, I bought my vette after I'd had that dream and that has changed my goals to now want a newer vette. Looking at c6's now. If I do that I may never need the OBD1 scanner. We'll see though. Plus 1320 website shows them all out of stock.
Team Owner
Joined: Jul 2004
Posts: 28,464
Likes: 3,288
From: Hartford WI
Thanks Aklim. I have thought about getting an OBD1 scanner for this car. I have a few good OBDII scanners but nothing for OBDI. I might be selling this car though after I get it working properly. My original goal was to get a gen 6 Camaro when my truck got paid off. Truck is paid off next month, I bought my vette after I'd had that dream and that has changed my goals to now want a newer vette. Looking at c6's now. If I do that I may never need the OBD1 scanner. We'll see though. Plus 1320 website shows them all out of stock.
Can't say I blame you for wanting newer. I am looking at the C6 or C7 myself and trying to see what I want and investigate what I need to do to sell the C4
Team Owner
Joined: Jul 2004
Posts: 28,464
Likes: 3,288
From: Hartford WI
Thanks Aklim. I have thought about getting an OBD1 scanner for this car. I have a few good OBDII scanners but nothing for OBDI. I might be selling this car though after I get it working properly. My original goal was to get a gen 6 Camaro when my truck got paid off. Truck is paid off next month, I bought my vette after I'd had that dream and that has changed my goals to now want a newer vette. Looking at c6's now. If I do that I may never need the OBD1 scanner. We'll see though. Plus 1320 website shows them all out of stock.
Your phone must be Android and not a fruit phone for it to work.
Last edited by aklim; May 14, 2021 at 08:18 AM.
Thread Starter
Heel & Toe
Joined: Jul 2018
Posts: 19
Likes: 2
From: Breezy Point, MN
Thank you for that offer. I might take you up on that. For now though, if I feel pretty good about the right place to send my ECM for rebuild, I'm going to go ahead and do that anyway. Especially if it's only a few hundred $$.