When I disconnect my battery car does not like to start?
01-17-2004, 07:56 PM
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When I disconnect my battery car does not like to start? When I disconnected my battery when I was working on the car for several hours and went to start the car it died? It would start then shut off instantly for no reason? After several times of trying it finally started and then ran ok. I have a custom tune that was done by Diablo that is a nitrous tune but I would think that would not be the problem. What do you guys think would cause this?
01-17-2004, 08:15 PM
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You are resetting your PCM each time you disconnect the battery. This causes the PCM to need to do a relearn for things like idle, before it stabilizes. This is normal, and has happened to both my LS1 cars (both when stock and modified). It will take the PCM 150-300 miles (depending on driving habits) for your PCM to fully 'relearn' most things. This is what I have observed with my LS1s.
Some OBD cars start up fine with no noticable relearn time (for idle). Not sure why LS1s have this issue, but it is in fact normal. Nothing to worry about.
I actually have a thread going about dianostic tests and relearn time in right now....
Some OBD cars start up fine with no noticable relearn time (for idle). Not sure why LS1s have this issue, but it is in fact normal. Nothing to worry about.
I actually have a thread going about dianostic tests and relearn time in right now....
01-18-2004, 01:30 AM
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Originally Posted by RPM WS6
You are resetting your PCM each time you disconnect the battery. This causes the PCM to need to do a relearn for things like idle, before it stabilizes. This is normal, and has happened to both my LS1 cars (both when stock and modified). It will take the PCM 150-300 miles (depending on driving habits) for your PCM to fully 'relearn' most things. This is what I have observed with my LS1s.
Some OBD cars start up fine with no noticable relearn time (for idle). Not sure why LS1s have this issue, but it is in fact normal. Nothing to worry about.
I actually have a thread going about dianostic tests and relearn time in right now....
Some OBD cars start up fine with no noticable relearn time (for idle). Not sure why LS1s have this issue, but it is in fact normal. Nothing to worry about.
I actually have a thread going about dianostic tests and relearn time in right now....
01-18-2004, 01:45 AM
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Follow the service manual procedure for idle relearn and it'll start up perfect the second time. Also, VE changes greatly affect how my car runs before the idle relearn is complete.
All the learning in our pcm is in the LTFT cells. If you develop a driving pattern that hits every cell you can learn in about 30 minutes.
All the learning in our pcm is in the LTFT cells. If you develop a driving pattern that hits every cell you can learn in about 30 minutes.
Last edited by 66ImpalaLT1; 01-18-2004 at 08:17 PM.
01-18-2004, 11:24 AM
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Originally Posted by 66ImpalaLT1
Follow the service manual procedure for idle relearn and it'll start up perfect the second time. Also, VE changes greatly affect how my car runs before the idle relearn is complete.
All the learning in our pcm is in the LTFT cells. If you develop a driving pattern that hits every cell you can in about 30 minutes.
All the learning in our pcm is in the LTFT cells. If you develop a driving pattern that hits every cell you can in about 30 minutes.
My car has a custom tune from Diablo for the nitrous. I also had them bump up the idle a tad. So from what I am understanding even with having a tune in the car it still needs to learn all the certain cells before it goes completely back to normal. Thanks for explaining this.
01-19-2004, 12:01 AM
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A tip given to me for overcoming the rough idle and speed up re-learn after diconecting battery or PCM re-set
re-connect battery
turn ignition to on position (Don't start)
fully depress accellorater pedal
release pedal
turn ignition off
repeat the above
then start
car will start and idle normally straight away !!
Cheers
John
re-connect battery
turn ignition to on position (Don't start)
fully depress accellorater pedal
release pedal
turn ignition off
repeat the above
then start
car will start and idle normally straight away !!
Cheers
John
