ecu/computer swap
jc83
06-04-2006, 08:55 PM
i was at junkyard and grabbed an ecu out of an 83 olds custom cruiser station wagon to use in my 84 el camino..just to fix a trouble code i read...code went away with the swapped olds ecu..but car idle was up and down it backfired once plus engine run on..however no trouble codes showed/no check engine light on..so does anyone know if its ok to swap ecus??
Gatorselky
06-06-2006, 08:37 PM
You can open the door to many problems switching ECU's without researching compatibility. You should check the # stamped on the ECU and the PROM # and go to:
http://www.efitune.com/broadcast_codes/
You will have to open the PROM access door on the ECU to read the PROM # ( usually 4 leters and 4 #'s).
I suspect you are backfiring because the distributor firing order is different. My Elky distributor fires 1~8 clockwise and many Oldsmobiles have 1~8 firing counterclockwise. I'm not saying the ECU will change how that happens however, the ECU you have substituted may pick up the difference and try to counter act through electronically altering something else...like your timing and causing your backfire.
If you really want to explore what was happening and causing your problem you should try the WINALDL program that you can download free at:
http://winaldl.joby.se/
With this program you can detect exactly where your problem is....fix it....or get someone to burn you a PROM and alter it.
I swapped a 4.3 to a 5.7 on my 85 Elky and changed ECU's, I didn't know how many things were controlled by the chip until I began the process. I wouldn't run your Elky much without finding out more as you could damage something.
Post what you find as many will be interesed in this.
http://www.efitune.com/broadcast_codes/
You will have to open the PROM access door on the ECU to read the PROM # ( usually 4 leters and 4 #'s).
I suspect you are backfiring because the distributor firing order is different. My Elky distributor fires 1~8 clockwise and many Oldsmobiles have 1~8 firing counterclockwise. I'm not saying the ECU will change how that happens however, the ECU you have substituted may pick up the difference and try to counter act through electronically altering something else...like your timing and causing your backfire.
If you really want to explore what was happening and causing your problem you should try the WINALDL program that you can download free at:
http://winaldl.joby.se/
With this program you can detect exactly where your problem is....fix it....or get someone to burn you a PROM and alter it.
I swapped a 4.3 to a 5.7 on my 85 Elky and changed ECU's, I didn't know how many things were controlled by the chip until I began the process. I wouldn't run your Elky much without finding out more as you could damage something.
Post what you find as many will be interesed in this.
jc83
06-07-2006, 07:09 PM
in regards to the computer swap--i forgot to mention the trouble code..it was code 54 which said there is a problem with the mixture control solenoid or ecu..i am on a second carb for my 84 el camino{ebay used carb nice condition though} and it still made the check engine light come on so thats when i got a code reader and got code 54...so when i was at the junk yard this past weekend thats when i pulled the ecu out of an olds custom cruiser station wagon..1984 therabouts...it was rebuilt..prom pins matched a rusty ecu from a junked el camino in the junk yard...i can return ecu but they do store credit crap--25$ no biggee i go there alot...so i broke down and bought a rebuilt carb off ebay ,factory rebuilt..should arrive monday the 12th...i will put original ecu back on fire it up and hopefully its the mixture control solenoid and not the ecu..
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