FAILURE DIAGNOSIS DEVICE FOR FUEL VAPOR PURGE SYSTEM, FUEL VAPOR PURGE DEVICE AND COMBUSTION ENGINE PROVIDED WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a failure diagnosis device for a fuel vapor purge system reducing quantity of fuel vapor discharged to the outside during failure diagnosis. SOLUTION: ECU 72 executes failure diagnosis since canister adsorption quantity is less than a predetermined judgment value at time t3 before execution of failure diagnosis when purge quantity during engine operation is G2 and purge quantity before failure diagnosis is more than necessary purge quantity G1. ECU 72 does not execute failure diagnosis since canister adsorption quantity is the predetermined judgment value or more at time t3 when purge quantity during engine operation is G3 and purge quantity before failure diagnosis is necessary purge quantity G1 or less. The necessary purge quantity G1 for judging possibility of failure diagnosis execution is determined according to temperature at time t3 before failure diagnosis execution. COPYRIGHT: (C)2006,JPO&NCIPI