PURPOSE: To improve acceleration performance, by injecting fuel from an accelerator pump, which operates in accordance with a change of intake negative pressure, to intake ports while controlling the fuel in accordance with the operative condition of an engine.
CONSTITUTION: Fuel from a pump 6 is injected from an injector 5, while one part of the fuel is injected from nozzles 25 to intake ports through a check valve 17, accelerator pump 10, acceleration fuel passage 22 and a check valve 23. A throttle valve 4 is rapidly opened, and when the negative pressure in an intake pipe 19 decreases, fuel in a chamber 14 is injected from the nozzles 25 by a spring 16 by decreasing the negative pressure in a bottom side chamber 15 of a diaphragm 13. The chamber 14 communicates with a return passage 9 through a passage 33, and an engine, which controls fuel in the chamber 14 by the second solenoid valve 32, increases acceleration fuel if the valve 32 is closed. The first solenoid valve 31 in the passage 22 is closed when the engine is placed in an unsteady condition, and unnecessary supply of fuel is prevented.
OKAWA KOZABURO
ISHIZUKA TAKASHI
