Dictionary of automotive terms. 2015.
ported vacuum switch — (PVS) a temperature actuated switch that changes vacuum connections when the coolant temperature changes (originally used to switch spark port vacuum; now used for any vacuum switching function that requires coolant temperature sensing) … Dictionary of automotive terms
ported vacuum advance — (PVA) A series of restriction devices between the distributor advance unit and the carburetor advance port to ensure that there is no vacuum advance during idle, but increasing ignition advance as the throttle opens … Dictionary of automotive terms
Vacuum switch — Prior to effective engine computers, engine vacuum was used for many functions in an automobile. Vacuum switches were employed to regulate this flow, and were commonly controlled by temperature, solenoids, mechanically, or directly. They operated … Wikipedia
vacuum advance — A mechanism on the side of the distributor that automatically varies the instant at which the spark occurs as a function of intake manifold vacuum. Vacuum advance provides the additional advance that is needed when the engine is operating at part … Dictionary of automotive terms
vacuum — An enclosed area in which the air pressure is below that of the surrounding atmospheric pressure. See air valve carburetor constant vacuum manifold vacuum ported vacuum advance pulse vacuum hublock venturi vacuum … Dictionary of automotive terms
vacuum delay valve — (VDV) a valve used by GM to bleed ported vacuum to the vacuum advance unit through a small orifice and control vacuum advance rate. Used to retard or delay the application of a vacuum signal. Also called delay valve … Dictionary of automotive terms
vacuum control valve — (VCV) a ported vacuum switch, controls vacuum to other emission devices during engine warm up … Dictionary of automotive terms
ported EGR valve — Operated by a vacuum signal from the carburetor EGR port. The port signal actuates the valve diaphragm. As vacuum increases, spring pressure is overcome, opening the valve and allowing EGR flow. The amount of the flow is dependent on the position … Dictionary of automotive terms
Manifold vacuum — Not to be confused with Vacuum manifold. Manifold vacuum, or engine vacuum in an internal combustion engine is the difference in air pressure between the engine s intake manifold and Earth s atmosphere. Manifold vacuum is an effect of a piston s… … Wikipedia
fuel-vacuum separator — Used to filter waxy hydrocarbons from the carburetor ported vacuum to protect the vacuum delay and distributor vacuum controls … Dictionary of automotive terms
