Throttle Body: Description and Operation

PURPOSE
The throttle body controls air flow to the engine.


OPERATION
- A cam/cable is used to rotate the throttle plate from idle to Wide Open Throttle (WOT) position.
- The plate position at idle is set by the lever contacting a throttle return control screw. The head of the screw is removed to make the idle plate set permanently.

CAUTION: Do not tamper with intake air throttle return control (trim) screws.

- The intake air flow is regulated by an Idle Air Control (IAC) valve.
- The WOT plate position is obtained when the lever contacts the body casting.
- At all throttle positions, the Throttle Position (TP) sensor produces an electrical signal which is used as an input to the Powertrain Control Module (PCM).

CAUTION: A sealant is applied to the downstream side of the throttle body plate and bore to reduce plate-to-bore leakage. This sealant should NOT be removed by cleaning.