Throttle Position Switch: Description and Operation

PURPOSE
This switch provides throttle position information to acceleration enrichment device.

CONSTRUCTION
Throttle switch consists of three switches (0°, 7°, and 66°), within one housing.

OPERATION
At oil temperatures greater than° F (35° C), acceleration enrichment device is controlled for 2 minutes after starting engine to a pulse-duty factor of 75 % for 0.5 seconds when the 0° and 7° switches are opened.

When the 0° switch is open, pulse-duty factor is increased to 75 % for 0.5 seconds. The air-fuel mixture is enriched during this period. As 7° switch is passed, mixture is enriched again.


The 66° switch is the full load contact. When it is closed, the full load signal is supplied to oxygen sensor control unit and pulse-duty factor is set to 50 %.

Full load enrichment is accomplished by lowering control pressure at control pressure regulator.