Throttle Body: Description and Operation

Throttle Body:

The Throttle Body Unit has staged primary and secondary throttle valves to control the amount of air delivered to the engine. Staging prevents the secondary throttle valve from opening until the primary valve has reached a certain opening angle. The staged throttle valve arrangement provides a better relationship between throttle valve opening and manifold pressure to obtain a more linear, or better throttle response.
The Throttle Position Sensor (TPS) and Idle Speed Control (ISC) motor are mounted on the throttle body assembly.
The throttle body contains ports located at, above, or below the throttle valve. These ports:
1. Generate the vacuum signals for the transaxle vacuum modulator, the fuel pressure regulator, the tank pressure control valve (TPCV) and MAP sensor.
2. Provide vacuum to purge the canister system.