Deaeration scheme (gasoline engine)
1 – tank with activated carbon and electromagnetic valve; 2 – control unit; 3 – fuel injection system; 4 – oxygen probe (lambda); 5 – coolant temperature sensor; 6 – electrical connection of the electromagnetic valve to the control unit; 7 – Ventilating the fuel tank; 8 – fuel supply to the injection system; 9 – connection of the activated carbon tank via the electromagnetic valve to the fuel injection system; 10 – fuel drain line; the arrow indicates the direction of fresh air
Activated carbon tank and its fastening (cars with gasoline engines)
1 – tank with activated carbon
The deaeration system with a tank with activated carbon is normally closed. When the gasoline is heated, the vapors formed enter the tank with activated carbon. There they are regenerated by fresh air sucked in due to the vacuum through the electromagnetic valve. The fuel captured by the activated carbon goes back into the suction line for subsequent combustion. The electromagnetic valve is controlled by the control unit of the fuel and ignition system.
Text copied from this resource (www.skodabook.ru)
It all works as follows: while there is no voltage at the terminals of the electromagnetic valve, the valve is open for bypass even with a small vacuum. (The deaeration electromagnetic valve can only be in working condition when the ignition is on). When voltage is applied to the solenoid valve coil, the valve closes. The duration of the opening is controlled by the control unit evaluating the signal from the throttle opening angle sensor and the signal from the oxygen probe (lambda). At engine operating temperatures below 60°C, the valve remains closed. The solenoid valve is part of the activated carbon tank.
Valve operation: the locking spring presses the anchor with the seal into the seat. The bypass is closed even under vacuum. When the control unit sends an impulse to the valve coil winding, the anchor will be attracted, overcoming the resistance of the spring, the valve will open, and fuel vapors will be able to get from the activated carbon tank into the engine.