Gasoline vapors formed in the fuel tank are discharged into the activated charcoal tank (volume of activated carbon 1.2 dm3) and from there through the shut-off valve to incineration. Quantity adjustable by filter valve (activated carbon tank). When refueling, this pipeline is closed and opens only when the fuel filler cap is tightened.
The valve of the activated carbon filter is permanently open until a throughput of approx. 3.6 kg/h is reached, depending on the pressure in the suction line. At the same time, the idling air coming from the purge is immediately mixed by the throttle actuator. On a signal from an oxygen probe (lambda), as well as regulating equipment, the control unit determines deviations from the value of lambda = 1 and corrects the ratio in the mixture.