V

VACUUM BOWL VENT VALVE:

VACUUM BOWL VENT VALVE/ THERMOSTATIC BOWL VENT VALVE - Vacuum and vacuum/temperature actuated On/Off valves. The Vacuum Bowl Vent Valve and the Vacuum Thermostatic Bowl Vent Valve are similar in appearance. The valves are used in the Evaporative Emission System to control vapor flow from the carburetor bowl to the carbon canister. With either valve, the flow path from the bowl to the canister is closed by manifold vacuum when the engine is running. The thermostatic valve also closes the bowl to canister flow path when the temperature is 90~ F or less (even without manifold vacuum). When the temperature of the valve is 120~ F or more, the valve is open (unless closed by manifold vacuum).

VACUUM OPERATED THROTTLE MODULATOR (VOTM) - Device used on some carburetors which varies throttle opening at idle dependent on engine load.


VAPOR LOCK - Vaporization of fuel within fuel lines. This condition is caused by routing fuel lines too close to the catalytic converter, exhaust manifold or other heat source.
VARIABLE VENTURI - Carburetor design with movable venturis.

VARIABLE VOLTAGE CHOKE (VVC) - A solid-state relay which is duty cycle modulated by the processor to effect variable choke control depending on the choke degree required.

VENTURI:

VENTURI - A restriction in the carburetor bore which causes air to accelerate and pressure to drop causing fuel to be drawn from the float bowl. The number of venturis is often used to designate a carburetor size, example 1V, 2V and 4V are terms used to designate the number of venturis.
VOLATILITY - The ability of a substance to vaporize quickly. Volatile liquids are normally quite flammable, e.g., gasoline.