coil/ignition module replacement 1992 cavalier

[stercus]

All of the published info i can find says that i need a Tech 1 scan tool to run an "Idle Learn" process when changing the coils or ignition control module. how will it effect the car if i don't do this but still change the coils and ignition module?

[marchi1]

Funny I didn't do this on my 91 with a 2.2 All I did was make sure that the battery staysed disconnected for like 30 minutes and the computer will reset and relearn everything. I installed new coils, and a new ICU and drove home with no problems......

[stercus]

the books say that specifically (only) the 3.1 requires this

[public]

I changed these items on my 1989 2.0 without the tool. I also just left the battery dissconnected for 30 minutes or so. Everything worked well.
Good Luck.

[public]

Just read your other post. I would go with the book on the 3.1. You might want to check with Flatrater in the buick forums, he is a GM mechanic.

[stercus]

I went ahead and tried without the tool and it seems to boe running without any problems

[GMMerlin]

The 3.1 engine will need to have the idle relearned after the ECM loses power (such as removing the battery cable)
First clean the throttle body and bore.
Next disconnect the battery for a few minutes..while the battery is disconnected, chock the front wheels and set the parking brake!
reconnect the battery and start the engine (with the A/C off)and place the shifter into drive..allow the engine to idle in drive until the cooling fans kicks on. (It is best if you hold the service brake during this procedure)
Once the fan turns on, turn the engine off and wait 15-30 seconds..then start the engine and repeat the procedure....this will allow the ECM to relearn the idle specs.