Loyale Sedan (4 Door) 2WD F4-1781cc 1.8L SOHC Turbo (1990)
Auxiliary Air Valve (Idle Speed): Description and Operation
Auxiliary Air Valve
PURPOSE
Provides fast idle when the engine is cold.
LOCATION
On top of thermostat housing.
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 coolant
temperature raises and 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. In addition, the
spring is heated by thermal transfer from coolant warming the thermostat housing.