| 摘要 |
PURPOSE:To correct an air-fuel ratio to a proper value responding to each running section, e.g. during running in a theoretical air-fuel ratio, during low temperature starting, by a method wherein a solenoid valve to perform drive in a duty ratio is provided, and by the feed of a drive signal of a proper duty ratio, pressurized air is properly fed to a regulating chamber. CONSTITUTION:With a key switch switched ON, a fuel pump 8 is actuated, a solenoid valve 40 is driven in a proper duty ratio, and a solenoid valve 44 in a fuel passage 10 is closed. Thus, pressurized air is introduced to a regulating chamber 20 to increase a pressure. Further, during low temperature running, a solenoid valve 31 is also driven in a proper duty ratio, and a throttle valve 5 is slightly opened. With the key switch brought into a starter position, the solenoid valve 44 is opened, and fuel in a fuel chamber 16 is injected from an injector 11 to a suction passage 2 by means of the fuel passage 10. In which case, by properly varying a duty ratio to the solenoid valve 40 during normal running and transient running, an air-fuel ratio can be corrected to a proper value. |
