Patent ID: 6722348
Filing Date: 2004-04-20
Classification: F02M

Abstract:
An abnormality detecting apparatus for a fuel vapor treating system, wherein the treating system includes a canister, which adsorbs fuel vapor generated in a fuel tank and purges the adsorbed fuel vapor to an intake passage of an engine, wherein the detecting apparatus performs an abnormality detecting procedure for detecting an abnormality in the treating system, wherein, when performing the abnormality detecting procedure, the detecting apparatus seals a vapor zone, which includes the fuel tank and the canister, so that the pressure in the vapor zone exceeds the atmospheric pressure, wherein the detecting apparatus determines whether fuel vapor is leaking from the vapor zone based on the pressure in the sealed vapor zone, the apparatus comprising:a valve device for selectively communicating the vapor zone with and disconnecting the vapor zone from the atmosphere, wherein, during the abnormality detecting procedure, the valve device disconnects the vapor zone from the atmosphere, and wherein, after the abnormality detecting procedure is ended, the valve device communicates the vapor zone with the atmosphere; and regulating means, wherein, when the valve device communicates the vapor zone with the atmosphere, the regulating means regulates a rate at which the pressure in the vapor zone is lowered.