i just got a new ECU for my car (well used actually)..but i had my mechanic run tests on it and everything to make sure its alright blah blah...but its still running like shit and stalling every once in awhile so i took it back and he said that sometimes putting in a new ECU it takes the car a good like hour or so of running to relearn everything...this just sounded a lil weird to me but i dont really know much lol....is this right?

I don't think so. I had to get a brand new ecu and it fired right up fine.

no way it should take an hour...maybe for a few minutes it'll run a little rough...and/or might not start the first time you crank it over and stall right away after it does start once or twice. I've reset mine several times and replaced it once and never had it take more than a couple of minutes to relearn enough to be driveable.

Swapped in an AFX/R and it started right up. No stutter. No hesitation. No stalling. How do you know the ECU is the problem? :wary

Originally posted by DR1665
How do you know the ECU is the problem? :wary

He doesn't. The mechanic knows though. :rolleyes

yes the ecu does have to relearn certain info like how much fuel to give the motor. I'm not sure but I think it re-programs after 10min at constant 50mph.

Originally posted by 420a2ner
yes the ecu does have to relearn certain info like how much fuel to give the motor. I'm not sure but I think it re-programs after 10min at constant 50mph.

yes, but no. it has a base map to start out with to get it running. it then "relearns" fine tuning aspects of the fuel and timing maps, to put it simply.

well i gave it back to my mechanic yesterday and he called me today and its FINALLY running good..its weird i dont have any CEL's now lol my dash looks kinda boring..anyway, he said they had to run it at idle for a LONG time (like 30 min) and drive quite a ways..it also had a few wiring problems so maybe he got them fixed 2 and it helped i dunno..and he put a new groudn wire in (i dunno which 1 didnt pop the hood yet)...all i care about is that i finally have a car that works lol
Mods: E-bay Intake, Vibrant Muffler, J Woodleys Ground Wire Kit, F&R Upper Strut Bars, B&M Short Shifter

Originally posted by reeveso
well i gave it back to my mechanic yesterday and he called me today and its FINALLY running good..its weird i dont have any CEL's now lol my dash looks kinda boring..anyway, he said they had to run it at idle for a LONG time (like 30 min) and drive quite a ways..it also had a few wiring problems so maybe he got them fixed 2 and it helped i dunno..and he put a new groudn wire in (i dunno which 1 didnt pop the hood yet)...all i care about is that i finally have a car that works lol Mods: E-bay Intake, Vibrant Muffler, J Woodleys Ground Wire Kit, F&R Upper Strut Bars, B&M Short Shifter

Sounds like he had to make a Packy run ("drive quite a ways"). Maybe he had to hit up his dealer. I suspect the "few wiring problems" is what really fixed everything. But great that you have a car that works!
MB

alright well its runnin real good now except its rough when idling..but only if its warm..when its still warmin up its fine..but the engine is kinda like, shaking when it starts acting up..could that be somethin w/ wiring/spark plugs/CAT?

Mods: E-bay Intake, Vibrant Muffler, J Woodleys Ground Wire Kit, F&R Upper Strut Bars, B&M Short Shifter

Originally posted by tim97rs

Originally posted by 420a2ner yes the ecu does have to relearn certain info like how much fuel to give the motor. I'm not sure but I think it re-programs after 10min at constant 50mph.

yes, but no. it has a base map to start out with to get it running. it then "relearns" fine tuning aspects of the fuel and timing maps, to put it simply.

yes thank you i already knew that.