Throttle Body: Description and Operation

Throttle Body:

PURPOSE
Controls idle air and intake air by varying throttle plate opening, also controls EVAP canister purging.

LOCATION
Mounted front of intake manifold. The canister/purge port is also located on top and is used to purge the EVAP system.

CONSTRUCTION
Is of the single-barrel, side-draft style.

OPERATION
Heated by coolant from the cylinder head. The idle adjusting screw, located on top, is used to vary the amount of air bypassing the throttle valve to adjust idle speed up/down. The throttle plate is controlled by a cable from the throttle pedal.