Patent ID: 6161423
Filing Date: 2000-12-19
Classification: F02M

Abstract:
A leak diagnosis apparatus for a fuel vapor treatment unit where fuel vapor produced in a fuel tank is collected by adsorbing into an adsorption means, and the fuel vapor collected in the adsorption means is purged under predetermined engine operating conditions and supplied to an engine, said leak diagnosis apparatus comprising:leak diagnosis means for diagnosing the presence of fuel vapor leaks by comparing a drive load of an electric pump for when air is pumped by said electric pump into a system of fuel piping of said fuel vapor treatment unit to be leak diagnosed, with a set judgement level of drive load threshold, wherein the set iudgement level is higher for higher fuel temperatures,fuel temperature detection means for detecting the temperature of fuel, wherein a fuel vapor leak is deemed to exist when the comparisons show that the drive load of the electric pump is less than the set judgement level, andjudgement level setting means for setting said judgment level based on the detected temperature.