Can anyone explain to me how the IAC unit on the throttle body works, as my car is a real pain to start cold and idles like its got a lumpy cam when warm. How do I go about checking how this unit works.

do u mean the ISC

idle speed control?


basically a small stepper motor that allows more or less air int oteh engine at idle

sounds liek yours is sticking and needs a clean
have a gander in the tech doccos pretty sure there is 1 to tell u how to clean it out!

Idle air control is tha same thing..
Yep clean... Disconnect it see if it makes any difference??
Also check coolant temp senser it can cause issues if not working correctly...