Idle Air Control Valve - Air Regulator Circuit: Description and Operation

IDLE AIR CONTROL VALVE-AIR REGULATOR
The Idle Air Control Valve (IACV) - Air Regulator provides an air bypass when the engine is cold for a fast idle during warm-up. A bimetal, heater and rotary shutter are built into the IACV-air regulator. When the bimetal temperature is low, the air bypass port opens. As the engine starts and electric current flows through a heater, the bimetal begins to turn the shutter to close the bypass port. The air passage remains closed until the engine stops and the bimetal temperature drops.