PURPOSE: To compensate variation of a fuel injection quantity due to a change of fuel presure, by setting a pressure sensor in the vicinity of a fuel injection valve and correctively controlling the fuel injection quantity through an electric signal from said pressure sensor.

CONSTITUTION: Air flows in through an air filter 3 and air flow sensor 4, and is introduced to a mixer 2. Fuel flows in through a fuel tank 5, fuel pump 6 and fuel filter 7, and is fed to a fuel pressure regulator 8. A pressure sensor 14 is provided in the vicinity of a fuel injection valve 9, and its electric signal is input to a control unit 1 to correctively control the fuel injection valve 9. In this way, variation of a fuel injection quantity due to a change of fuel pressre can be compensated to control fuel injection to a desired adequate quantity.