Tercel Sedan 4-Door L4-1456cc 1.5L SOHC (3E) (1994)
Throttle Positioner (TP): Description and Operation
PURPOSE
The Dash Pot reduces Hydrocarbons (HC) and Carbon Monoxide emissions by returning the throttle plate slowly to the idle position during
deceleration. This allows the air fuel mixture to burn more completely than if the throttle were closed abruptly.
OPERATION
Air becomes trapped by the vacuum transmitting valve (VTV) and becomes a buffer on the diaphragm. When the throttle valve is released and
comes in contact with the Dash pot (DP) actuator pin, the air is forced back out of the DP filter slowly, returning the throttle valve slowly to its
idle position.
CONSTRUCTION
The Dash Pot consists of a spring loaded diaphragm that extends when the throttle is opened, thus drawing in air through suction.