초록

A method for cooling a fuel injection system and fuel injection systems are proposed that improve the hot-starting performance of the internal combustion engine.

대표청구항 ▼

A method for cooling a fuel injection system and fuel injection systems are proposed that improve the hot-starting performance of the internal combustion engine. d by said comparison; and diagnosing an abnormality of said variable valve timing apparatus when said abnormality diagnosis is permitted.

A method for cooling a fuel injection system and fuel injection systems are proposed that improve the hot-starting performance of the internal combustion engine. d by said comparison; and diagnosing an abnormality of said variable valve timing apparatus when said abnormality diagnosis is permitted. 9. A method for diagnosing a variable valve timing apparatus according to claim 8, wherein at least one of said predetermined limit value and said predetermined period is variably set corresponding to an engine temperature. 10. A method for diagnosing a variable valve timing apparatus according to claim 8, wherein at least one of said predetermined limit value and said predetermined period is variably set corresponding to an engine rotation speed. 11. A method for diagnosing a variable valve timing apparatus according to claim 8, wherein an abnormality diagnosis is permitted on a condition that an engine operating condition and an environment state satisfy predetermined conditions, in addition to the condition that the change amount has been kept equal to or less than said predetermined limit value for a predetermined period. 12. A method for diagnosing a variable valve timing apparatus according to claim 8, wherein an abnormality diagnosis is permitted on a condition that the control target value of said rotation phase does not coincide with a reference value regulated by a stopper, in addition to the condition that the change amount has been kept equal to or less than said predetermined limit value for a predetermined period. 13. A method for diagnosing a variable valve timing apparatus according to claim 8, wherein the presence of abnormality is judged when a deviation between the control target value of said rotation phase and an actual value of said rotation phase has been kept out of a predetermined range for a predetermined period or more. 14. A method for diagnosing a variable valve timing apparatus according to claim 8, wherein the valve timing is controlled by changing said rotation phase with respect to the crankshaft with a friction braking by an electromagnetic brake.