Fuel Evaporation System: Operation

Gasoline vapors from fuel tank are collected in expansion tank and then routed to evaporative canister through the vent line. With engine off, vapors are absorbed in the charcoal contained in the evaporative canister for storage. When engine is running, fresh air is drawn into the canister where it mixes with the fuel vapors. Plenum chamber vacuum then sucks the mixture into the engine where it is burned.

Air inlet valve allows outside air into the system to prevent excessive vacuum from forming in system. A check valve in line prevents fuel leakage in event of vehicle rollover.