| 摘要 |
An object of the invention is to provide a technology that enables to make the feed pressure as low as possible without inviting a misfire or a deviation of the air-fuel ratio, in a fuel injection control system for an internal combustion engine equipped with a low pressure fuel pump and a high pressure fuel pump. According to the invention, to achieve the object, in a fuel injection control system for an internal combustion engine in which fuel discharged from a low pressure fuel pump is supplied to a fuel injection valve with its pressure boosted by a high pressure fuel pump, while a lowering process of lowering feed pressure or the discharge pressure of a the low pressure fuel pump, the lowering process is suspended and restarted with reference to the tendency of change in an integral term used in a proportional-integral control of the duty cycle of the high pressure fuel pump. |
