Upgrade 85 ECM?
Le Mans Master
Joined: Jul 2001
Posts: 6,252
Likes: 2
From: Silicon Valley Kalifornia
Ski_down_it is right. There is only one real advatage of upgrading to a later ECM. That would be the MAF burn off module. The '85 are darn expensive used. The late ECMs use two simple relays to command the MAF sensor.
Thread Starter
Racer
Joined: Sep 2003
Posts: 454
Likes: 1
From: Lompoc CA
Originally Posted by GRX
Ski_down_it is right. There is only one real advatage of upgrading to a later ECM. That would be the MAF burn off module. The '85 are darn expensive used. The late ECMs use two simple relays to command the MAF sensor.
What is this part, where is it located, and why is it so expensive ($cost?)?
Richard
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Originally Posted by GRX
Ski_down_it is right. There is only one real advatage of upgrading to a later ECM. That would be the MAF burn off module. The '85 are darn expensive used. The late ECMs use two simple relays to command the MAF sensor.
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Originally Posted by nonetooclose
If this is the case, then it would be an easy matter to design and build a simple circuit to do the same that the ECM is doing without the expensive part?
What is this part, where is it located, and why is it so expensive ($cost?)?
Richard
What is this part, where is it located, and why is it so expensive ($cost?)?
Richard
ECMs are pretty inexpensive ~90 dollars new. You are right though, and there are probably less than 40 dollars worth of components in them.
Aftermarket ones alike, what your paying for there is someones/groups expertise and knowhow.
Advanced
Joined: Apr 2018
Posts: 61
Likes: 1
Hello Everyone,
Hopefully everyone is still around because its now 2018 and I have some questions pertaining to exactly this post. In the past year and a half I have just about completely torn apart my 1985 Corvette because it needed just about a complete re-build. Essentially I am running performance heads with an aftermarket/medium camshaft, Smog Delete and new injectors with my Cold Start (9th Injector) removed as well. My car runs and performs good under load. However, upon start up it takes longer than I'd like to turn over and when i'm idling, the RPM's skip around a little, Plus I dislike the factory settings for when my fan turns on. I'm trying to turn the fan on around 180F. That being said the car needs a tune, I can build an engine but I'm not experienced with ECM swaps. I'm looking at upgrading my 1985 ECM to a 1986 ECM because i'm learning that It's significantly easier for tuning due to the fact that I can program a chip to go into the 1986 ECM. Firstly, is Oski_dwn_it suggesting that I can use my 1985 ECM to accomplish what I'm trying to get done? If so, How? If I need to swap ECM's can someone tell me if the ECM's will swap/connect without having to do any splicing and I'm not sure what is implied with
"Re-pining" so maybe someone here has a step by step instruction or a link to a video as to what needs to be accomplished. All advice is appreciated.
Thanks in advanced,
Hopefully everyone is still around because its now 2018 and I have some questions pertaining to exactly this post. In the past year and a half I have just about completely torn apart my 1985 Corvette because it needed just about a complete re-build. Essentially I am running performance heads with an aftermarket/medium camshaft, Smog Delete and new injectors with my Cold Start (9th Injector) removed as well. My car runs and performs good under load. However, upon start up it takes longer than I'd like to turn over and when i'm idling, the RPM's skip around a little, Plus I dislike the factory settings for when my fan turns on. I'm trying to turn the fan on around 180F. That being said the car needs a tune, I can build an engine but I'm not experienced with ECM swaps. I'm looking at upgrading my 1985 ECM to a 1986 ECM because i'm learning that It's significantly easier for tuning due to the fact that I can program a chip to go into the 1986 ECM. Firstly, is Oski_dwn_it suggesting that I can use my 1985 ECM to accomplish what I'm trying to get done? If so, How? If I need to swap ECM's can someone tell me if the ECM's will swap/connect without having to do any splicing and I'm not sure what is implied with
"Re-pining" so maybe someone here has a step by step instruction or a link to a video as to what needs to be accomplished. All advice is appreciated.
Thanks in advanced,
Last edited by RME1993; Dec 14, 2018 at 11:31 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Cruising
Joined: Jun 2017
Posts: 12
Likes: 2
From: Los Angeles
Hello Everyone,
Hopefully everyone is still around because its now 2018 and I have some questions pertaining to exactly this post. In the past year and a half I have just about completely torn apart my 1985 Corvette because it needed just about a complete re-build. Essentially I am running performance heads with an aftermarket/medium camshaft, Smog Delete and new injectors with my Cold Start (9th Injector) removed as well. My car runs and performs good under load. However, upon start up it takes longer than I'd like to turn over and when i'm idling, the RPM's skip around a little, Plus I dislike the factory settings for when my fan turns on. I'm trying to turn the fan on around 180F. That being said the car needs a tune, I can build an engine but I'm not experienced with ECM swaps. I'm looking at upgrading my 1985 ECM to a 1986 ECM because i'm learning that It's significantly easier for tuning due to the fact that I can program a chip to go into the 1986 ECM. Firstly, is Oski_dwn_it suggesting that I can use my 1985 ECM to accomplish what I'm trying to get done? If so, How? If I need to swap ECM's can someone tell me if the ECM's will swap/connect without having to do any splicing and I'm not sure what is implied with
"Re-pining" so maybe someone here has a step by step instruction or a link to a video as to what needs to be accomplished. All advice is appreciated.
Thanks in advanced,
Hopefully everyone is still around because its now 2018 and I have some questions pertaining to exactly this post. In the past year and a half I have just about completely torn apart my 1985 Corvette because it needed just about a complete re-build. Essentially I am running performance heads with an aftermarket/medium camshaft, Smog Delete and new injectors with my Cold Start (9th Injector) removed as well. My car runs and performs good under load. However, upon start up it takes longer than I'd like to turn over and when i'm idling, the RPM's skip around a little, Plus I dislike the factory settings for when my fan turns on. I'm trying to turn the fan on around 180F. That being said the car needs a tune, I can build an engine but I'm not experienced with ECM swaps. I'm looking at upgrading my 1985 ECM to a 1986 ECM because i'm learning that It's significantly easier for tuning due to the fact that I can program a chip to go into the 1986 ECM. Firstly, is Oski_dwn_it suggesting that I can use my 1985 ECM to accomplish what I'm trying to get done? If so, How? If I need to swap ECM's can someone tell me if the ECM's will swap/connect without having to do any splicing and I'm not sure what is implied with
"Re-pining" so maybe someone here has a step by step instruction or a link to a video as to what needs to be accomplished. All advice is appreciated.
Thanks in advanced,
Heel & Toe
Joined: Oct 2024
Posts: 16
Likes: 3
1985 corvette
By all means do it now...for one simple reason. If you do it at the same time that you do the engine swap and the engine won't start or run right, you'll be troubleshooting 2 major systems as the possible problem. If you do it now, and get it all running correctly with your current engine, you'll have one less potential headache later.
As far as it being a "difficult" upgrade, hogwash, I did mine in 3 hours. Just some simple repinning of the ECM and some splicing of the wires at the ECM connectors. If you'd like I can give you a detailed run through of how I did it and the differences between what I did vs the directions on the (most used) web page.
The only problem I can see is that if a smog station ever has to hook a scanner to it, and that scanner uses the vin for its means of deciding which ecm file to use... it might have fits.
As far as it being a "difficult" upgrade, hogwash, I did mine in 3 hours. Just some simple repinning of the ECM and some splicing of the wires at the ECM connectors. If you'd like I can give you a detailed run through of how I did it and the differences between what I did vs the directions on the (most used) web page.
The only problem I can see is that if a smog station ever has to hook a scanner to it, and that scanner uses the vin for its means of deciding which ecm file to use... it might have fits.
Cruising
Joined: Jun 2017
Posts: 12
Likes: 2
From: Los Angeles
You will also need a chip
The old chip will not be compatible with the upgraded ecm. You will want a chip that matches your automatic or manual transmission for the new ECMS original year. I got a chip from an 87 automatic, but I still have not done the swap.
