Throttle Body: Description and Operation

The Throttle Body is an integral part or the Upper Intake Manifold Assembly.
The throttle body 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.