Throttle Positioner System: Operation: Pickup
The throttle positioner system is speed controlled. A vacuum switching valve responds to speed determined by the speed sensor and computer. The switching valve then allows or cuts off vacuum to the throttle positioner diaphragm. When speed is above a certain point (approximately 7 MPH) and throttle is suddenly closed for deceleration, the throttle positioner holds throttle plate at a slightly open position. When vehicle decelerates below this speed, vacuum is cut off and throttle plate returns to normal idle position.