Throttle Body: Description and Operation

Throttle Body:

PURPOSE
Regulates amount of air allowed into engine according to driver demand for power.

LOCATION
On dynamic chamber at intake air inlet.

OPERATION
Throttle valve opening is controlled by the driver through accelerator pedal and cable. The farther the throttle is opened, the more air and fuel are burned in each cylinder cycle, and the more power is produced.

CONSTRUCTION
Consists of a housing with primary and secondary throttle valves, control linkage, and throttle position sensor. BAC valve is mounted on top of throttle body.

Secondary throttle valve is connected to the primary valve by a progressive linkage. Secondary does not begin to open until primary throttle valve is opened more than a specified amount. The progressive linkage opens the secondary throttle faster than the primary valve, so that both valves will reach wide open throttle at the same time.