Joyner JNSZ1600QL Owner's Manual page 126

After long time since engine stopped, the temperature in the fuel tank will rise (Since the vehicle
doesn't move, the dynamic ventilation is not enough.) and the pressure in the fuel tank will rise.
——When the fuel tank is full, the multi-function valve 4 is closed. The fuel cannot flow into charcoal
canister 6, therefore it doesn't damage charcoal canister.
If the pressure in the fuel tank (1) rises beyond the specified value, two-way check valve (2) will open
reducing the pressure in the fuel tank. If necessary, the valve may open reversely to vent inward when the
fuel tank is vacuumed. —When the fuel level is at middle or low, when it exceeds a specified pressure,
the multi-function valve
(4) will permit the fuel vapor to reach the charcoal canister (6) and be absorbed by the activated carbon
granule. The operation when engine is running (figure.179) 。 Solenoid (7) is powered on by ignition switch
and is controlled by the injection system ECU directly by
the following modes: When the valve is open, the vacuum in engine will suck the vapor collections in the
charcoal canister into the lower part of throttle valve. When powered off, the valve will close to prevent the
λ s ensor from sucking the vapor when it doesn't work.
8. Fuel vapor recirculation solenoid valve (condensing chamber EC1) The fuel vapor
recirculation solenoid valve is designed to regulate the vapor volume (from the charcoal
canister) controlled by ECU. When the solenoid valve is deenergized, the valve closes.
Fig.178
125