Auxiliary Air Valve

The auxiliary air valve, or regulator, provides additional air to the engine to increase idle speed when the engine is cold. It allows air to by-pass the throttle valves which are closed at idle.

A heating coil in the valve is connected to the fuel pump circuit. As the coil warms up, it gradually closes the air passage. The valve is calibrated to maintain a smooth idle without a large engine speed change as the engine is warming up.