What happens to my ecu?!?!?!

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speedmaxx
Second Gear
Posts: 330
Joined: Wed Aug 05, 2009 5:07 am

What happens to my ecu?!?!?!

Post by speedmaxx »

So I finally got my car turbo!!!! My car had been running great in na form, as soon as I slapped the turbo set up in she fired right and ran great! Tons if power! Smoothish idle considering the cams. But over all running great.

But anyways I figured I would reset the ecu considering the big time change up on the engine. So I unhooked the battery for the night and reinstalled it in the morning. As soon as I fired her up she stalled out almost instantly so I was forced to give her a little gas to keep her breathing. After a few revs she was idling rough but I let her be for about 10min. I then turned her off and let her sit for 5 min. Then I went for a test drive, under boost she pulls fine but when not in boost she's running terrible. Extremely choppy idle, seems like multiple cylinders are misfiring.

A little back round info, about 6months ago I rest the ecu and I got the same problem, only difference is that it had never stalled on start up when the battery cable was re attached. Back then I just gave the reset another shot and all was well, the car ran great from then on.

So my question is, is my ecu dieing? Is it like slowly failing? Am I missing a step in this whole ecu relearn?

Also I just want thanks big time to all of those helped with my turbo build!!! I am hooked on boost!!!
93 legacy l
to much to list....
speedmaxx
Second Gear
Posts: 330
Joined: Wed Aug 05, 2009 5:07 am

Re: What happens to my ecu?!?!?!

Post by speedmaxx »

Anybody?
93 legacy l
to much to list....
b3lha
In Neutral
Posts: 41
Joined: Mon Jun 25, 2007 4:51 pm

Re: What happens to my ecu?!?!?!

Post by b3lha »

Your ECU has learned how to compensate for your engine mods. When you reset the ECU it forgets everything it has learned and tries to use the base maps, which are calibrated for an unmodified engine. So it runs like a dog until it learns the correct fuel and timing trims for your engine.

Give it some time and it should improve. Once it is running properly, you shouldn't reset it.
2 x 1991 JDM SVX Version L 4WS
1 x 1994 JDM SVX Version S40ii
1 x 1996 Legacy 2.2GX wagon (dual-ratio)
For ECU & TCU Diagnostics and Datalogging. See http://www.alcyone.org.uk/ssm
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