Vapor Vent System

System provides a vapor space above gasoline surface in fuel tank. This area is sufficient to permit adequate breathing space for tank vapor valve assembly.

All vapor valves are mounted on fuel tank and use a small orifice that allows only vapor and not liquid fuel to pass into line running to canister.

Fuel vapors trapped in sealed fuel tank are vented though vapor valve assembly on top of fuel tank. Vapors are routed through a single vapor line to carbon canister in engine compartment.

Vapors are stored in carbon canister until they are purged into engine while engine is operating.

On vehicles equipped with fuel/vapor return lines, vapor generated in fuel supply line is continuously vented back to fuel tank. Venting prevents engine surging from fuel enrichment and assists in hydrocarbon emission control.