For cold starting, the rpm is increased and the symptoms described are correct. However the idling speed should go down to 650 - 750 rpm after warming up.
The engine is surging due to the idling speed being higher than expected.
Possible causes are :
1. Idling speed adjusted too high.
2. Clogged coolant hoses to the IAC or lack of coolant in system.
3. Faulty IAC.
Wednesday, October 6th, 2010 AT 3:28 PM