| 摘要 |
PROBLEM TO BE SOLVED: To resolve or minimize a torque fluctuation of an engine following cleaning actuation of a variable valve timing mechanism. SOLUTION: Throttle valve is checked (S201) whether totally closed or not. If totally closed, a value of an initial flag FLGINI is referred to (S208). If FLGINI=0 and it is the first time after shifting from open state to totally= closed state of the throttle, the temperature of the cooling water TW indicating engine temperature is checked (S210) whether it exceeds a low temperature judgment threshold value TWL or not, and engine speed NE is checked (S211) whether it exceeds a low rotational frequency judgment threshold value NEL or not. As a result, if TW>TWL and NE>NEL, a cleaning flag FLGCLN is set to 1 (S212) to allow a cleaning operation. Thus, deterioration of the sliding ability at sliding part of a variable valve timing mechanism or a hydraulic control valve and the biting of foreign matters are prevented by suppressing precipitation and a deposit of impurities or the foreign vnatters while preventing generation of torque shock due to combustion fluctuation of the engine.
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