PURPOSE: To prevent variations in fuel pressure, by providing two first and second pumps in series between a fuel bomb and a fuel injection valve, and as well by providing a regulator in parallel with the first pump so that both pumps are driven when the pressure of the fuel bomb is low, but the second pump 2 alone is driven when the pressure of the bomb is high, for pressurizing fuel.

CONSTITUTION: A first fuel pump 3, a second fuel pump 4 and a fuel reservoir 5 are arranged in series in a passage between a fuel bomb 1 and a fuel injection valve. A pressure reducing regulator 8 is disposed in parallel with the first fuel pump 3, and solenoid valves 2, 7 are provided upstream of the pump 3 and the regulator 8, respectively. In accordance with the detection value of a pressure sensor 9 in the fuel bomb 1, a controller 10 issues its control signal to open the solenoid valve 2 but close the solenoid valve 7 to drive both first and second fuel pumps 3, 4 when the pressure of the bomb 1 is low, while to close the solenoid valve 2 but open the solenoid 7 to drive the second fuel pump 4 alone when the pressure of the bomb 1 is high.