Auxiliary Air Valve (Idle Speed): Description and Operation

Auxiliary Air Valve:

PURPOSE
Provides fast idle when the engine is cold.

LOCATION
Under R.H. intake runners.

OPERATION
when the engine is cold, the valve is open. The valve allows intake air to by-pass the throttle valve, therby raising engine idle speed. As the PTC heater (inside the valve) warms, it gradually closes off the air passage, lowering idle speed.

CONSTRUCTION
A coiled bi-metal spring is attatched to a shutter valve. A PTC heater element inside the unit heats the spring, closing the shutter.