How BMW3/5 EVAP System Works?

The following schematic diagrams the Evaporate Emissions Control (EVAP) System of BMW 3- and/or 5- series. This evaporative emissions control system (see the diagram) may help you understand the EVAP system on the M10 engine of the vehicle.

And here are How BMW3/5 EVAP System Works:

1. Fuel vapour is created in the fuel tank when the engine is not running. The EVAP system stores this fuel vapour in a charcoal canister.
    – when engine is cruising: purge control valve opened, small amount of fuel vapour is drawn into the intake manifold and burned.
    – when the engine is idling (starting cold): purge valve prevents any vapours from entering the intake manifold and causing excessively-rich fuel mixture.
2. A faulty EVAP system will only affect engine driveability when the engine is warm.