Patent ID: 6363921
Filing Date: 2002-04-02
Classification: F02M

Abstract:
An automotive vehicle that is powered by an internal combustion engine and comprises:a tank for storing volatile fuel that is consumed by the engine; a vapor storage canister that comprises a dirty air port in communication with headspace of the tank to cooperatively define an evaporative emission space for containing vapor generated by the evaporation of liquid fuel in the tank and that comprises a vapor absorbent medium separating the dirty air port from a clean air port; and a system for selectively communicating the evaporative emission space to atmosphere through a vent valve and to an intake system of the engine through a purge valve to establish different flow paths for different operating modes of an evaporative emission control system, including a leak verification system, for the evaporative emission space, wherein for a purge mode, a purge flow path extends from atmosphere through the vent valve, through the evaporative emission space, and through the purge valve to the engine intake system, for a pre-conditioning phase of a leak verification mode, a pre-conditioning flow path extends from atmosphere through the vent valve and the purge valve to the engine intake system without passing through the evaporative emission space, and for a test phase of the leak verification mode, a test path extends from the evaporative emission space through the dirty air port, through the canister medium, through the clean air port, and through the purge valve to the engine intake system.