Throttle Opener System

The throttle opener system is used on all high altitude and California manual transmission equipped models. See Figure. Functioning as a throttle positioner, above 15-20 MPH, the speed sensor in the speedometer causes the throttle opener solenoid valve to open, allowing vacuum to enter the throttle control valve.

When this vacuum exceeds a preset value (during deceleration), the throttle control valve opens and the throttle control diaphragm opens the throttle a fixed amount to improve combustion.

When vehicle speed drops below approximately 5-10 MPH, or the vacuum drops below the throttle control valve's preset value, the throttle control valve closes and the residual vacuum in the system is relieved through the orifice in the throttle control valve.