EVAP Control System
EVAP system minimizes fuel vapor escaping into atmosphere. EVAP control system consists of a fuel filler cap, liquid/vapor separator, EVAP 2-way valve, EVAP canister purge valve, EVAP control canister, EVAP canister vent valve, rollover valves and EVAP purge control solenoid valve.
Fuel vapor inside fuel tank is directed to liquid/vapor separator. When pressure in separator increases to 0.7-1.0 psi (0.05-0.07 kg/cm2 ) a pressure relief valve opens and fuel vapor moves to EVAP canister for storage. Liquid/vapor separator tank and relief valve (2-way valve) are located in fuel filler neck at right rear of vehicle. Fuel filler cap contains a relief valve to prevent excessive pressure or vacuum build-up in tank.
When ECM detects desired engine operation it opens EVAP control canister purge valve, allowing a regulated flow of fuel vapor from EVAP control canister. Fuel vapor is drawn into intake manifold and burned in combustion chamber.