PURPOSE: To enable continuing operation in such a way that at the time of trouble in the controller, stop valves are changed over, and fuel feeding is done by a mechanical means by intstalling a pump, a booster and stop valves which are interlocked with the engine in an electronic fuel injector.

CONSTITUTION: A booster B is formed to be first and second pressure chamber B2, B3 by means of big and small pistons, the first pressure chamber B2 is communicated through a third stop valve V5 to a first pump F, and communicated theough a second stop valve V4 and a first change-over valve V1 to a working oil feeder C. Then the second pressure chamber B3 is communicated through a fourth stop valve V6 to a first pump G and a fuel feeder D, and further its discharge side is communicated through a first stop valve V3 to a third pressure space A2d in an injection nozzle device (A). Though a governor H and first and second change-over valves V1 and V2 are controlled by means of a controller E, when the E is in trouble, the first and second stop valves V3, V4 are closed, the third and fourth stop valves V5 and V6 are opened, and a needle valve A3b is directly controlled by means of fuel pressure in the booster (A).