PURPOSE: To prevent the over-rich state during acceleration by perfectly suspending the fuel feed by an acceleration pump only when the all conditions of water temperature, car speed, and transmission shift position are fulfilled.

CONSTITUTION: A solenoid valve 13 is installed midway into a fuel feeding passage 11 communicating from an acceleration pump 5 to a carburetor passage 1. The valve piece 13a of a valve 13 is supported by a valve rod 13b, and the switched contact between two valve seats 13c and 13b is permitted, and when the valve piece 13a contacts with the valve seat 13c, the valve piece 13a cuts-off the communication between the fuel feeding passage 11 and an accelerating nozzle 12. Further, the valve 13 is energized by the control signal supplied from a microcomputer 16, into which each detection signal is input from a water-temperature sensor 17, car-speed sensor 18, and a transmission switch 19. Therefore, when an engine is at a prescribed temperature or more, at a prescribed speed or less, and at a prescribed shift position, the fuel feeding passage 11 is cut-off by the valve 13.