ECU resetting/setting idle

[DSM4G63T]

I found out that I needed a new ecu because my car cuts out as soon as the boost comes on. I swapped my ecu from a friends car and it boosted fine. I ordered a used edu from a guy in the classifieds and installed it and the car runs extremely rough. What would I have to do to the ecu or the car. He said that my fuels curves are different, need to be reset, or need to readjust the idle. But why did my friends ecu work perfect with just a swap? Thanks for any input.

 

[spoolup]

when power is removed from a ECU it may take a few minutes (about 20) for the ECU to learn. My car would idle really rougha nd stall occasionally upon stopping at a light. Every time I worked on the car I would start it up and keep it running (if need be holding the gas pedal in to keep RPMs at 1000 or so) then drive out of hte neighborhood and onto the freeway and drive bout 10 minutes. Then stop and let it idle for a few minutes shut it off and restart, worked great. Now with DSM link I do not have this problem but it was with the same ECU. I always blamed my SAFC setting and the way they were altering the ECU. your profile shows your car as stock so I do not know if the above will help you or not. But give it a try. It sucks having to do this everytime I reset the ECU. You do not have any CEL right?

 

[DSM4G63T]

No it does not show a CEL. The car is back to stock now because I am tring to sell it and I just needed the computer to work so I can get rid of it. If there was a CEL I would be able to look it up with my palm. I will take you advise and go run the car for a bit, I have only ran it for about 2 minutes so far. Thanks for your input. I will give you some + feedback.

 

[steve]

The ECU you put in the car should have been a MD166262. What did you put in.
Since capacitor problems are universal to 1G ECUs, did you open the "new" one and check it before installing it?

Steve

 

[DSM4G63T]

I do have a MD1662262, and I just opened it and there is a leaky cap. I ran it for a few minutes in the car before opening it and my cat got red hot and transfered a bunch of heat into interior. Hopefully the guy will return it for me. If anyone has a ECU for sale for an AWD 92 I will take it off your hands. Thanks Steve.

 

[DSM4G63T]

There was no leaky caps in my old ECU, but my car would not boost correctly. What would be bad inside my ECU? Could I fix it?

 

[steve]

There was no leaky caps in my old ECU, but my car would not boost correctly.

You mean there were no leaky caps that you could see. I see plenty of cases where the leakage is contained under the capacitor while it disolves the copper traces. That can continue until it shorts and burns up the ECU or the electrolyte finally leaks out from under the capacitor and eats through something than stops the ECU from working.

Steve