Deceleration Control System: Description

Deceleration systems are used to reduce HC emissions. On Colt and Colt Vista models a dashpot and deceleration spark advance system consisting of an engine speed sensor and solenoid valve is used. On Ram-50 Pickups, an air switching valve, coasting air valve and dashpot are used on all manual transmission models (except Federal Pickups).

The air switching valve cuts off fuel to by-pass holes and pilot outlet by supplying additional air to slow idle passage. The coasting air valve supplies additional air to intake manifold. The deceleration spark advance system advances ignition timing by changing carburetor ported intake vacuum to intake manifold vacuum.