PURPOSE: To enhance the starting characteristic of an engine while it is cold by furnishing two fuel supply means to be driven by drive current with different voltages, and by using either of the means selectively in accordance with the temp. of engine and the result of sensing the source voltages for respective drive currents.

CONSTITUTION: Main fuel injection valve 15 operating accurately at a high voltage is furnished in the neighborhood of the suction port 7 of a suction manifold 6, and an aux. fuel injection valve 17 operating at low voltage is installed on a servo tank 8. While the engine is in operation, temp. of the engine given by a water temp. sensor 20 and the source voltage of battery 29 are read in an electronic control circuit 14 sequentially. Then it shall be judged whether the source voltage is over a specific level, and if the result is YES, fuel injection is made from the main fuel injection valve 15 in accordance with the engine temp. If the result is NO, on the other hand, fuel injection shall be made from the above- mentioned aux. fuel injection valve 17, alike in accordance with the engine temperature.