Intake Air Plenum: Description and Operation

The throttle chamber, located between the intake manifold and air flow meter, is equipped with a valve. This valve controls the intake air flow in response to accelerator pedal movement. The rotary shaft of this valve is connected to the throttle valve switch. This valve remains closed during engine idling, and the air required for idling passes through the bypass port into the intake manifold. Idle adjustment is made by the idle speed adjusting screw located in the bypass port. There is another bypass line in this throttle chamber to pass sufficient air through the air regulator into the intake manifold when a cold engine is started.