Throttle Plate Assembly Operation

The throttle plate assembly is mounted on the intake manifold chamber. See Figure . It contains 2 throttle plates which are connected to the accelerator by conventional throttle linkage. A throttle position switch is built into the assembly. This switch informs the ECU, by electrical signal, of wide open throttle and idle conditions. The ECU uses this information to adjust air/fuel mixture to meet engine demands.

On vehicles equipped with air conditioning or power steering, a fast idle valve is built into the assembly to compensate for decreased idle speed during AC operation, during an extreme turn, or engine starting condition. Additional idle air is supplied through an auxiliary air circuit in the throttle assembly.