Throttle Body: Description and Operation

EARLY MODEL VEHICLES

Throttle Body:

The throttle body is mounted at the rear of the intake manifold and supplies air to the intake manifold during part or open throttle operation. At closed throttle intake air is supplied by the Idle Speed Regulator (ISR). The throttle body houses the throttle valve and the Throttle Position Sensor (TPS). The throttle valve, controlled by the vehicle operator, via the throttle cable, modulates air flow into the engine during vehicle operation. Fuel mixture, idle speed, and injector pulse width are controlled by the Electronic Control Unit (ECU).

LATE MODEL VEHICLES

Throttle Body:

The throttle body is mounted at the rear of the intake manifold and supplies air to the intake manifold. The throttle body houses the throttle valve, the Automatic Idle Speed (AIS) motor, and the Throttle Position Sensor (TPS). The throttle valve, controlled by the vehicle operator, via the throttle cable, modulates air flow into the engine during vehicle operation. At idle, air flow modulation is controlled by the Single Board Engine Controller II (SBEC II) through actuation of the AIS motor.