| 摘要 |
PURPOSE: A method for diagnosing a fuel system of a direct injection type internal-combustion engine and a diagnosis control system are provided to concretely inspect malfunction of a high pressure fuel pump, and aging or leakage of a high pressure fuel pipe. CONSTITUTION: A method for diagnosing a fuel system of a direct injection type internal-combustion engine includes the steps of detecting real fuel pressure with a fuel pressure sensor, performing feedback fuel pressure control to reduce pressure deviation of the real fuel pressure to target fuel pressure, detecting abnormality of the fuel system by monitoring the real fuel pressure(S16), diagnosing leakage of a high pressure fuel pipe if the pressure deviation continues though the fuel system is normal, forcedly converting a predetermined combustion mode into a rarefaction combustion mode and an equal combustion mode, or a stratified combustion mode(S17), detecting abnormal part of the system, and performing feedback air fuel ratio in the predetermined equal combustion mode if the abnormal part is detected.
|
