Auxiliary Air Valve (Idle Speed): Description and Operation

COMPONENT DESCRIPTION
The IACV-air regulator contains wax, a piston and a spring. When the engine coolant is cold, the wax is compressed allowing an air by-pass port to open. This provides for a fast idle setting while the engine heats. As the engine coolant warms, the wax expands, closing the air by-pass port and decreasing the idle speed.