| 摘要 |
PROBLEM TO BE SOLVED: To diagnose the presence or absence of abnormality of an upstream side purge passage system of an evaporation gas purge system of an engine with a supercharger. SOLUTION: A purge passage 28 is branched into an upstream side purge passage 29 and a downstream side purge passage 30, the upstream side purge passage 29 is connected with the upstream side of a compressor 22 in an intake pipe 12, the downstream side purge passage 30 is connected with the downstream side of a throttle valve 16, and an upstream side purge passage opening and closing valve 32 is provided in the upstream side purge passage 29. The upstream side purge passage opening and closing valve 32 is opend and closed while a purge control valve 31 is closed during fuel cut control at deceleration time to change amount of bypass air flowing from the upstream side of the compressor 22 onto the downstream side of the throttle valve 16 through a path passing through the upstream side and downstream side purge passages 29, 30 and diagnose the presence or absence of abnormality of the upstream side purge passage 29 and the upstream side purge passage opening and closing valve 32 based on amount of change of pressure in the intake pipe detected by an intake pipe pressure sensor 18 in the process. COPYRIGHT: (C)2007,JPO&INPIT
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