| 摘要 |
PURPOSE:To improve fuel consumption at deceleration, by providing a bleed air introducing means in a slow line at the downstream of a carburetor slow fuel feed control valve and performing air bleed when a slow fuel feed is restarted further intake negative pressure is not less than a set value. CONSTITUTION:When an engine is operated at a medium and high speed, a fuel cut valve 12 is opened through a control circuit 18 by outputs of a speed detector 14 and negative pressure switch 16, but a low line is not substantially operated by low intake negative pressure. Then a vehicle goes into a deceleration state, if a throttle valve 4 is closed, the intake negative pressure rises not to output control voltage from the control circuit 18, and the fuel cut valve 12 is closed. And then, intake negative pressure lowers to not higher than a prescribed value, then the fuel cut valve 12 is reopened, simultaneously a negative pressure selector valve 44 is operated through a delay circuit 46 and clutch switch 48, and the intake negative pressure is transmitted to a chamber 32 in an air bleed valve 22. In this way, a valve body 36 is opened to feed bleed air to a feed pipe 20. |
