Throttle Body: Description and Operation

Throttle Body Assembly:

The throttle body assembly controls airflow to the engine through a double butterfly-type valve. The throttle position is controlled by multiple-link, progressive opening, throttle linkage. The body is a single piece die casting made of aluminum. It has a dual bore with an air bypass channel around the throttle plate. This bypass channel controls both cold and warm engine idle airflow as regulated by an air bypass valve assembly mounted directly to the throttle body. The valve assembly is an electro-mechanical device controlled by the EEC computer. It incorporates a linear actuator which positions a variable area metering valve. Engine coolant is diverted through the throttle body mounting pad to improve cold weather operation.

Component Location:

Other features of the air throttle body assembly include:
a. A pre-set stop to locate the WOT position.
b. A throttle body mounted throttle position sensor.