System for diagnosing and controlling high-pressure fuel system for in-cylinder fuel injection engine

摘要

A system for controlling an in-cylinder fuel injection engine (1) determines that a high-pressure fuel system is abnormal, when meeting at least one of conditions that the fuel pressure Pf of the high-pressure fuel system does not reach a preset pressure PFS(S24) even if a predetermined period of time elapses after the engine start-up(S22), that the fuel pressure Pf of the high-pressure fuel system is not within an ordinary fuel pressure range defined by the lower limit PFL and the upper limit PFH after the engine start-up(S27,S28), and that the fuel injection pulse width Ti continues to exceed the upper limit TiNGMAX, which can not usually be obtained, for a predetermined period of time at a lean air-fuel ratio (S30 SIMILAR S33). Thus, the abnormality of the high-pressure fuel system of the in-cylinder fuel injection engine (1) can be accurately diagnosed.