Patent ID: 7789071

Claim:
A fuel supply system for an internal combustion engine, comprising: a low pressure pump that is capable to pressurize fuel; a low pressure fuel supply passage that is capable to supply fuel that was pressurized by the low pressure pump to a low pressure fuel injection mechanism which injects fuel into an intake passage; a branch passage that branches off from the low pressure fuel supply passage and through which the fuel that was pressurized by the low pressure pump flows; a high pressure pump which is capable to pressurize the fuel supplied via the branch passage, the high pressure pump being driven by the internal combustion engine; a high pressure fuel supply passage that is capable to supply fuel that was pressurized by the high pressure pump to a high pressure fuel injection mechanism which injects fuel into a cylinder; and a pulsation reducing mechanism provided on an intake side of the high pressure pump, wherein, when the internal combustion engine is started by only injecting fuel from the low pressure supply passage into the intake passage, the pulsation reducing mechanism closes off communication between the low pressure fuel supply passage and the high pressure fuel supply passage until a pressure of fuel in the low pressure fuel supply passage reaches a predetermined pressure value required for starting the internal combustion engine.