Patent ID: 8333175

Claim:
A fuel supply system comprising: a fuel pump capable of supplying fuel stored within a fuel tank to a fuel injecting valve device of an engine; a pressure regulator including a pressure regulating chamber, into which a part of the fuel supplied from the fuel pump to the fuel injecting valve device can be introduced, and a back pressure chamber, into which a part of the fuel pressurized by the fuel pump can be introduced, wherein a pressure of the fuel within the pressure regulating chamber can be regulated according to a back pressure produced within the back pressure chamber, and surplus fuel not to be used within the pressure regulating chamber can be discharged from the pressure regulator; a change-over device configured to be able to change between a fuel introduction state for introducing the fuel into the back pressure chamber of the pressure regulator and an atmospheric pressure introduction state for introducing an atmospheric pressure into the back pressure chamber of the pressure regulator, so that a system fuel pressure of the fuel supplied to the fuel injecting valve device can be changed by the change-over device; a check valve arranged in a fuel supply path leading from the fuel pump to the fuel injecting valve device, the check valve being positioned on an upstream side of a first diverting point in the fuel supply path, from which the fuel is introduced into the pressure regulating chamber of the pressure regulator; and an outflow prevention device capable of preventing outflow of the fuel within the back pressure chamber of the pressure regulator when the engine is stopped while the system fuel pressure being heightened.