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Hey guys I want to replace my ECU or have it fixed.
Since the idle has been messed with on the throttle body and due to the shops not being able to calibrate the TPS correctly. My ECU may have gone into limphome mode. Car runs but cant keep idle steady some days it will run at 1200/800rpms the next day it runs at 600rpms.
replaced..
EGR, TPS, IAC, New Tune Up, Timming Belt.
No vacuum leaks
My question is.. if I put a new or rebuilt ECU in...all the adjustments that WERE made to the TPS, idle, and timing...would that put the ECU back in limphome??
What needs to be done when putting in a new ECU?
 

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Maybe an explanation of "limp home mode" is in order - if the ECU detects a failed sensor, regardless of the cause of the failure - which could be an actual bad sensor, bad wiring, sensor out of adjustment or an internal ECU failure causing the ECU not to see the sensor, it will substitute a predetermined value for that sensor so that you can "limp home" rather than be stranded with a non functional vehicle.

The exact form that limp home will take will change depending on the failed sensor or combination of sensors - if your current ECU is in limp home mode, chances of a replacement ECU also going into limp home mode are VERY high - note that three of the four causes listed above are external to the ECU, and also note that with the exception of the internal ECU failure, once you repair the problem, the ECU will detect the "absence" of the fault and revert to normal operation the next time the car is started.

You can also "clear" by disconnecting the battery, and the ECU will simply redetect any failures on the next start.
Start by reading the check engine codes, then investigate & repair the cause of each code.
 

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Yes that is correct, the ECU will come out failsafe mode once the fault has been fixed. If you pull the codes and list them here we will be able to give you further guidance. there is a brief explanation of fail-safe and limp modes here:

http://www.rhinopower.org/Tech/limp.html

Incidentally you sent me an email but you don't have your profile set to receive emails so I couldn't reply.
 

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Your check engine light must be on with the key on, and then off once the car starts. If it is on when the car is running, pull the codes as per instructions here:
Check Engine Light
Write them down, then reset the computer by pulling the fuse for the dome light for a minute. Then drive the car some more, and see what codes come back - these codes will be real, rather than in memory. Post what codes you get, for more info.
Normally, in our older cars, if the ECU itself is actually at fault (the 3 capacitors that dry out and need to be replaced), the car will only crank and not start at all. As your car is running, your problem is most probably with specific sensors, or the wiring to them, and your ECU should pick this up with a code.
 
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