1985 ECM Question/Research
Thread Starter
Instructor
Joined: May 2010
Posts: 235
Likes: 0
From: Southern Colorado
1985 ECM Question/Research
I am doing research into 1985s because i am pretty much decided that I want an '85.
On TPI Parts, on their page on ECMs and Proms, it states I have read on several occassions that late in the 1985 production run, GM had already changed to the ECM and harness that they later used in 1986. I have not confirmed this myself, so I can't say for sure that its true. If this is true though, it is possible though to come across a 1985 model which uses the 86-89 ECM.
Has anyone been able to confirm or deny this?
On TPI Parts, on their page on ECMs and Proms, it states I have read on several occassions that late in the 1985 production run, GM had already changed to the ECM and harness that they later used in 1986. I have not confirmed this myself, so I can't say for sure that its true. If this is true though, it is possible though to come across a 1985 model which uses the 86-89 ECM.
Has anyone been able to confirm or deny this?
Pro
Joined: Jul 2002
Posts: 729
Likes: 4
From: Yukon OK
I have never heard this but checking at Eckler's I see that there is only one ECM available for the 85. Could be that really late in 85 they started the 86 production run. Not sure. The 85 ECM is really slow and not well supported by scan tools
Having an 85 I can tell you there are a lot of one off and unique parts like the Bosch MAF Burnoff module. Some of these parts are expensive. Doing it over I think I would look at 88 or later. They had the better headlights and a number of other improvements.
The only mid production year change I know about is 86. Late 86 went to an aluminum head. Don't know of others.
Having an 85 I can tell you there are a lot of one off and unique parts like the Bosch MAF Burnoff module. Some of these parts are expensive. Doing it over I think I would look at 88 or later. They had the better headlights and a number of other improvements.
The only mid production year change I know about is 86. Late 86 went to an aluminum head. Don't know of others.
Thread Starter
Instructor
Joined: May 2010
Posts: 235
Likes: 0
From: Southern Colorado
I have never heard this but checking at Eckler's I see that there is only one ECM available for the 85. Could be that really late in 85 they started the 86 production run. Not sure. The 85 ECM is really slow and not well supported by scan tools
Having an 85 I can tell you there are a lot of one off and unique parts like the Bosch MAF Burnoff module. Some of these parts are expensive. Doing it over I think I would look at 88 or later. They had the better headlights and a number of other improvements.
The only mid production year change I know about is 86. Late 86 went to an aluminum head. Don't know of others.
Having an 85 I can tell you there are a lot of one off and unique parts like the Bosch MAF Burnoff module. Some of these parts are expensive. Doing it over I think I would look at 88 or later. They had the better headlights and a number of other improvements.
The only mid production year change I know about is 86. Late 86 went to an aluminum head. Don't know of others.
I know that the later C4s had a host of improvements and I would love to have many of them, roller valve train, improved suspension, etc. However, there are three things that I can't stand, VATS, ABS, and CHMSL. They all started in '86, hence my search for a '85.
I know of at least one mid year change in the '85, the overdrive defeat switch went from the center console to the shifter.
Safety Car
Joined: Feb 1999
Posts: 4,724
Likes: 16
From: Little Elm TX
I am doing research into 1985s because i am pretty much decided that I want an '85.
On TPI Parts, on their page on ECMs and Proms, it states I have read on several occassions that late in the 1985 production run, GM had already changed to the ECM and harness that they later used in 1986. I have not confirmed this myself, so I can't say for sure that its true. If this is true though, it is possible though to come across a 1985 model which uses the 86-89 ECM.
Has anyone been able to confirm or deny this?
On TPI Parts, on their page on ECMs and Proms, it states I have read on several occassions that late in the 1985 production run, GM had already changed to the ECM and harness that they later used in 1986. I have not confirmed this myself, so I can't say for sure that its true. If this is true though, it is possible though to come across a 1985 model which uses the 86-89 ECM.
Has anyone been able to confirm or deny this?
If you can get past that, they're fine.
In regards to when exactly they converted over..... I've never heard of an 165 ecm in a stock 85..... so that would be new to me. I thought the conversion was definitely between the model years. But consider that the 86 model year is in-large built in the year 1985.... so maybe that is what they were talking about.
good luck !
