Evaporative Emissions System: Description

The fuel vapor system consists of internal fuel tank venting, a vacuum-pressure fuel tank filler cap, a vapor separator (Wagoneer only) or expansion tank, a vapor storage canister (V-8 auto, trans, only), a limit fill valve and internal carburetor venting. Fuel vapor pressure in the fuel tank forces the vapor through vent lines to a vapor separator (Wagoneer only) or to an expansion tank (all other vehicles). Vapor is then routed through a single vent line to the limit fill valve which regulates the vapor flow to the charcoal canister or to the cylinder head cover.