Throttle Opener
The function of the throttle opener is to open the throttle plate of carburetor slightly during periods of deceleration. During deceleration, manifold vacuum rises and air/fuel mixture is such that normal combustion cannot continue. The throttle opener supplies engine with an adequate charge of mixture to maintain proper combustion during deceleration. At the moment when manifold vacuum increases, the control valve opens to transfer vacuum to servo diaphragm chamber and throttle valves of carburetor open slightly. As vehicle speed decreases, vacuum control valve begins to close gradually, keeping manifold vacuum at a predetermined level. As a result, both low hydro-carbon emissions and normal engine braking during deceleration are obtained. An altitude corrector is provided with a slight preload to compensate for variation of atmospheric pressure.