4 Runner 2WD L4-144.4 2366cc 2.4L SOHC (22R-E) (1990)
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Dashpot: Description and Operation
Fig. 10 Dash Pot System
Fig. 11 Dash Pot System Schematic
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. The Dash Pot consists of a spring loaded diaphragm
that extends when the throttle is opened, thus drawing in air through suction. The 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 DP actuator pin, the air is forced back out of the
DP filter slowly, returning the throttle valve slowly to its idle position.
