Deceleration Valve

This valve is used on some 2.8L (173") V6 engines to prevent backfiring in the exhaust system during deceleration. Valve is normally closed, but opens when sudden deceleration increases vacuum to point of overcoming internal spring pressure. This allows additional air into the intake manifold to prevent overly rich mixtures from entering combustion chambers. Air trapped in chamber above vacuum diaphragm will bleed at a calibrated rate through the delay valve portion of the integral "Check and Delay Valve", reducing vacuum acting on diaphragm. When vacuum load on diaphragm and spring load are equal, valve assembly closes, shutting off air to intake manifold.