| 摘要 |
PROBLEM TO BE SOLVED: To prevent the diffusion of evaporative fuel in the atmosphere positively after leak diagnostic in evaporative fuel processor. SOLUTION: An air pump 13 is actuated and a directional control valve 14 is changed over to connection with the air pump 13, so that the air the air pump 13 force-feeds flows through the directional control valve 14 and into a new charge inlet 9 of a canister 7 which feeds it into purge lines 6 and 10, upon which operation the operating current value of the air pump 13 is measured as a leak level. The leak level is compared with a determination level. A leak level not larger than the determination level triggers a leak decision. After the leak diagnostic, the air pump 13 is shut down and the directional control valve 14 is changed over to communication with an atmosphere opening 12, so that the internal pressure of a fuel tank 5 is released out from the atmosphere opening 12. In the release control, the ratio of opening of the directional control valve 14 in relation to the atmosphere opening 12 is limited in dependence on the charging state of the canister 7.
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