C 2500 Truck 2WD V8-454 7.4L VIN J SFI (1996)
Throttle Body: Description and Operation
Diagram
Description
The throttle body assembly is mounted on the intake manifold plenum, and is used to control air flow into the engine, thereby controlling engine output.
The throttle valve within the throttle body is opened by the driver through the accelerator controls. During engine idle, the throttle valve is almost closed,
and air flow control is handled by the Idle Air Control (IAC) valve.
The throttle body also provides the location for mounting the Throttle Position (TP) sensor and for sensing changes in engine vacuum due to throttle
valve position. Vacuum ports are located at, above, or below the throttle valve to generate vacuum signals needed by various components.
Legend
(1) Throttle Body Assembly.
(2) IAC Valve Assembly O-ring.
(3) IAC Valve Assembly Attaching Screw.
(4) Idle Air Control (IAC) Valve Assembly.
(5) TP Sensor O-ring
(6) Throttle Position (TP) Sensor.
(7) TP Sensor Attaching Screw.
