| 摘要 |
PROBLEM TO BE SOLVED: To specify a failure caused by valve element return delay of a pressure regulator by diagnosing the failure of a pressure control valve in the case the fluctuation width of pressure is detected and exceeds a prescribed value. SOLUTION: An engine fuel feed system comprises a fuel pump 1 for boosting fuel as a fuel feed system for feeding fuel to the fuel injection valve of an internal combustion engine, a fuel piping 3 for supplying high pressure fuel to each injection valve 6, a pressure sensor 2 for measuring fuel pressure in the fuel piping 3, an accumulator 5 for suppressing pressure fluctuation in the fuel piping 3, and a pressure regulating valve 4 for setting pressure in the fuel piping 3 to a prescribed value. The failure of the pressure regulating valve 4 is judged in the case where the detected fluctuation width of pressure in the fuel piping 3 exceeds a prescribed value. It is thus possible to specify a failure caused by valve element return delay of the pressure regulator from the measuring result of fuel pressure. |
