Auxiliary Air Valve (Idle Speed): Description and Operation

Idle Air Control Valve-Air Regulator:

PURPOSE
The Idle Air Control Valve - Air Regulator allows air to bypass the throttle plate when the engine is cold, providing fast idle.

OPERATION
When the engine is cold a passage in the regulator is open to allow air to by-pass the throttle plate allowing fast idle. As the engine starts and electric current flows through a heater, the bimetal begins to turn the shutter to close the by-pass port. The air passage remains closed until the engine stops and the bimetal temperature drops.