Deceleration Devices

Deceleration devices are used to reduce levels of hydrocarbons entering the atmosphere during vehicle deceleration.

DECELERATION SPARK ADVANCE SYSTEM
This system is activated by carburetor ported or intake manifold vacuum. During vehicle deceleration, manifold vacuum advances ignition timing. When vehicle speed falls below a predetermined value, the vacuum applied to the distributor diaphragm is changed from manifold to ported vacuum by the movement of a solenoid valve, maintaining smooth vehicle operation. Solenoid valve operation is controlled by the electronic control unit (ECU) of the feedback carburetor system.

DASH POT
Used on manual transaxle equipped vehicles, the dash pot reduces hydrocarbon emissions by delaying throttle valve closing to its normal idling position.