Throttle Body: Description and Operation

Throttle Body:

PURPOSE
To regulate air flow entering the intake manifold. Air flow through the throttle body is controlled by the throttle blade. The throttle blade is connected to the accelerator pedal by the accelerator cable.

COMPONENTS
It contains the Throttle Position Sensor (TPS), Idle Air Control (IAC) Motor and Manifold Absolute Pressure Sensor (MAP).

Throttle Body:

OPERATION
An air bypass passage is controlled by the IAC motor. The air bypass passage is used to supply air for idle conditions. A throttle valve (plate) is used to supply air for above idle conditions. The accelerator pedal cable, speed control cable (when equipped) and transmission control cable are connected to the throttle arm. A (factory adjusted) set screw is used to mechanically limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the Powertrain Control Module.