DESCRIPTION
The system is designed to prevent fuel vapor from entering the atmosphere. Fuel system is completely sealed and vented only through a carbon canister. System consists of pressure/vacuum relief fuel filler cap, a roll-over valve, charcoal canister, purge valve and various connecting hoses.
OPERATION
The fuel tank is fitted with a pressure/vacuum relief filler cap which allows excessive tank pressure to vent. It also allows air into tank if vacuum should become excessive due to a malfunction in fuel evaporation system. Fuel tank vapor is vented by a line through roll-over valve to the charcoal canister.
The roll-over valve is located in the vent line close to the fuel tank. Valve is designed to prevent fuel spillage if vehicle rolls over. Valve is open until vehicle is at a 45° angle, or more, from horizontal.
The carbon canister is filled with activated carbon. Fuel vapor from the tank is adsorbed by carbon when engine is not running. When engine is running faster than idle, fuel vapor is drawn into the engine and burned.
TESTING
Note. Testing information not available.
MAINTENANCE
Replace foam plastic filter in the bottom of the charcoal canister every 45,000 miles.