Throttle Opener System
Control valve is set to allow passage of vacuum to throttle opener diaphragm when engine vacuum is greater than 20.1-21.7 in. Hg. (510-550 mm Hg) during deceleration. Under running conditions, other than fully closed throttle deceleration, intake manifold vacuum is lower than preset value of throttle control valve; therefore, control valve will not be actuated. Vacuum remaining in system is bled off by passage in control valve.