24 and the comparator 160 generates a high level voltage thus turning the transistor tr22 on since the collector of the transistor tr22 is connected to the cathode of the diodes d 2 and d 5 in the enrichment circuit 13 when the operating time of the starter exceeds a predetermined time the currents i 1 and i 2 flow into the timer circuit 16 thus stopping the considerable enrichment of the fuel this predetermined time is increased with decrease in the cooling water temperature since the capacitor c 20 is charged to the output voltage of the operating condition detector 7 as mentioned previously this predetermined time may be maintained at a constant value which is independent of the cooling water temperature and this may be accomplished simply by connecting one end of the resistor r 21 to the constant voltage source v b with this second embodiment the considerable enrichment of fuel during the engine starting period is stopped when the operating time of the starter exceeds the predetermined time after which the fuel injection time is controlled at the values obtained with the starter off as shown in fig3 and the values indicated by the lowermost characteristic curve in fig4 consequently if for example the battery voltage drops thus decreasing the spark energy of the spark plugs and the starter motor is operated.