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 use a small orifice that allows only vapor and not solid fuel to pass into line running to canister. Vapor valve is mounted on fuel tank using a rubber grommet.

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.