Throttle Positioner System: Operation: Starlet
The throttle positioner system is vacuum controlled. When the engine is cold, the BVSV is open and holds positioner in a set position. When the engine is warm, the throttle open and vacuum at TP port is low, the positioner is also in a set position. When the throttle is released, as during deceleration, the positioner keeps it from closing completely until vacuum bleeds through the jet restrictor. High vacuum present at TP port will then pull the positioner back and allow the throttle to close completely.