Could a faulty Idle Air Control valve cause the vehicle to speed up on its own? Does anyone have a check for an IAC, my Haynes book does'nt cover it?

Help. The new coil pack did not solve the problem. Car stalls and will also accelerate all on its own. I've also changed the O2 sensor. Air inlet temp, TPS and Mass air flow all check out fine.
Steve

Everthing checked out, but I did replace the O2 sensor. Problem still exists and has become more frequent, would stall while running. Sometime codes would come up and others no codes. I did notice when the stall was happening and even though the vehicle was still moving the speedo went to 0. I ran ...

Finally had it fault again. This time I got the following codes:
13 - Oxygen Sensor
22 - Throttle Position Sensor
23 - Intake Air Temp. Sensor
29 - Gear Switch Diagnosis ( 4th gear )

This seems weird to get so many codes. Any ideas before I start replacing everything???

Thankyou, all really good info. If sensors were the source of my problems wouldn't I get a Code reading. I am using a GM Code reader by Innova Equus that produces signals by way of the dash 'Check Engine' light ( cheap). I had a similar issue with my 89 ford P/U and it turned out to be failure of ...

I am having engine stalling issues with my 89 Bonneville. Will only stall at an idle otherwise runs great. When I back off on the gas to a coast engine may stall or when sitting at a stop. Checked Codes and nothing came up.