FUEL INJECTION CONTROL METHOD AND DEVICE FOR INTERNAL COMBUSTION ENGINE

A fuel injection control method for an internal combustion engine is provided. The internal combustion engine includes a fuel pump (38) that pressure-feeds fuel, a fuel injection valve (19) that injects the fuel pressure-fed by the fuel pump directly into a cylinder of the internal combustion engine (1), and a fuel pressure detection device (45) that detects a pressure of the fuel pressure-fed by the fuel pump. The fuel injection control method executes a first smoothing process (S3) of performing a smoothing process on a detected fuel pressure by first smoothing, a second smoothing process (S4) of performing a smoothing process on the detected fuel pressure by second smoothing different from the first smoothing, and a selection process (S5) of selecting, based on an operating state of the internal combustion engine, whether to execute fuel injection control (S6, S7) based on a first detected fuel pressure smoothed by the first smoothing process or fuel injection control (S8, S9) based on a second detected fuel pressure smoothed by the second smoothing process.