Fuel Evaporation System: Operation
When engine is not running, vapor from expanding fuel in fuel tank collect in expansion tank. From the expansion tank, vapor flows out of tank and into charcoal canister through liquid/vapor separator. Manifold vacuum then pulls vapor from canister into combustion chamber for burning when engine is running.
When ignition is off or engine is being cranked, the ECM keeps the bowl vent solenoid valve closed to allow float bowl vapor to flow to canister.
When engine is running, the ECM opens the bowl vent solenoid valve to allow float bowl vapor to flow through inner vent passage into carburetor bore.