PURPOSE: To cause a fuel injection timing to coincide with a normal fuel injection timing.

CONSTITUTION: Fuel is fed into a fuel chamber 7 through operation of an engine- driven fuel supply pump 2, and supplied into a pressurizing chamber 24 via a fuel supply passage 25 whereupon the fuel within the chamber 24 pressurized by a plunger 11 is fed into a fuel injection valve 29. The fuel injection timing is controlled by operation of a timer 19. The bulk modulus of the fuel in the chamber 24 compressed by the plunger 11 is estimated from the fuel temperature of the fuel chamber 7. A duty-ratio control is made of an opening/closing control valve 22 of the timer 19 to expedite the timing with which compression of the fuel is started with the plunger 11, in corresponding relation to the degee by which the bulk modulus becomes smaller.