Description

At constant RPM, the vacuum signal to both chambers A and B, of the mixture control valve is stabilized. On sudden deceleration, the vacuum signal applied to the upper chamber through a calibrated opening is weaker than the direct signal applied to the lower chamber. This difference allows the valve to open and fresh air is routed to the intake manifold. After a few seconds, the vacuum in the two chambers stabilizes through the balancing port, and the mixture control valve closes.