96 ciera

[zeihert]

My 1996 ciera 3.1 motor starts great but stays up on high idle even when warm unless I turn the car off and restart it then it runs fine.It only does this when its cold out.I need help on this one please.I think its the computer itself now.I can get a used one for around 30.00 bucks

[maxwedge]

Get it on a scanner for coolant temp sensor readings, clean the iac and passages also.

[zeihert]

Need more ideas on this one.Maybe tps is bad,but ive got no check engine light coming on at all.You would think that it would if something was bad???

[maxwedge]

Have you done a full scan and looked at the tps and iac readings?

[zeihert]

Originally Posted by maxwedge

Have you done a full scan and looked at the tps and iac readings?

Yes I had a full scan done at a dealer and nothing came up of course this was when the engine was warm and it only acts up when its cold.After it warms up I need to turn the ignition off and restart the car to bring the idle down.Im stumped!!!!!!!!!!!

[caddyman379]

I doubt this will work, but it won't hurt. I would disconnect the negative battery cable for maybe half an hour. This will clear the ICM. Then, allow the vehicle to idle from a cold start to warm and let run for 15 minutes at idle. Then, drive the vehicle invarying condtions so it learns your driving habits. This would be highway, city, stop-and-go, etc.

If i'm wrong please feel free to correct me.

[zeihert]

Originally Posted by caddyman379

I doubt this will work, but it won't hurt. I would disconnect the negative battery cable for maybe half an hour. This will clear the ICM. Then, allow the vehicle to idle from a cold start to warm and let run for 15 minutes at idle. Then, drive the vehicle invarying condtions so it learns your driving habits. This would be highway, city, stop-and-go, etc.

If i'm wrong please feel free to correct me.

The idle wont come down till the car has been driven at least 30 to 50 miles when its good and warmed up.I did what you said and there was no change it went up to high idle right away.I think it might be the computer??????????

[caddyman379]

sorry, let me rephrase that: Disconnect the negative battery cable. This will reset the ECM, which controls the idle among other things. If the idle is somewhat normal, then follow the steps I gave you. If not, then stop the engine.

A high idle is normal when cold, but not extremely high.

What have you done on cars? Tuneups? Im curious how mechanically inclined you are

[zeihert]

Originally Posted by caddyman379

sorry, let me rephrase that: Disconnect the negative battery cable. This will reset the ECM, which controls the idle among other things. If the idle is somewhat normal, then follow the steps I gave you. If not, then stop the engine.

A high idle is normal when cold, but not extremely high.

What have you done on cars? Tuneups? Im curious how mechanically inclined you are

I think its the computer????????????