Hey everyone, over the past year or so my 91 V6 has had an on/off again issue where it seems the ECM doesn't know what to do after the battery is disconnected. I have tried to drive it for an entire hour after reconnecting the battery so it can relearn everything, but to no avail. Upon ignition the RPM's will jump up to 15,000 and then slowly come back down to normal idle but will feel quite rough, this is a random occurrence, sometimes it happens and sometimes it will start normally. It feels almost fine while driving, maybe a tad slower than usual, but coming to a stop it will plummet the RPMs almost stalling it. It also doesn't accelerate or shift smoothly when leaving a stop. So far I have replaced: spark plugs, spark plug wires, distributor cap and rotor, air filter, fuel filter, IAC, and the ECM itself. When I got the ECM replacement, it ran better than it ever did. Until i disconnected the battery to install new speakers a week ago, and everything went back to square one. I'd love to hear anyone's input on this issue that has been haunting my Camaro for a while now, thanks in advance.

 

it races to 15k rpm ?

 

On a cold start it will jump up to 15k, then slowly drop down to 10k where the cold idle is, until it warms up and slowly comes down to around 5k. On warm starts it will jump right up to 15k, then come down to 5k. Sometimes this happens, sometimes it does not; it seems like the car runs better when it doesn't happen.

 

your tachometer is way off or your about to throw rods. I don’t see that your engine can rev that high.

 

Hah! Pardon the brain fog, I have a high fever right now. I meant 1,500 not 15,000. As the 91 RS tach states 5, 10, 15

 

https://www.thirdgen.org/forums/v6/1...procedure.html

 

I'll try this in the next day or two, thanks! Do you know if this is something that has to be done every time the battery is disconnected? I'm wondering what might be causing it if not.

 

Probably if S.A.M is lost