| 摘要 |
PURPOSE:To prevent an air-fuel mixture from being overthickened as a rapid increase in intake suction pressure is relieved, by installing a solenoid valve in a bypass passage leading to a throttle valve in a suction system, while controlling the solenoid valve for its opening or closing according to a state of engine operation. CONSTITUTION:A solenoid valve 16 is installed in a bypass passage 15 leading to a throttle valve 2. As elements detecting a state of engine operation, there are provided with a throttle opening sensor 17 and an idle switch 19 detecting an idle position. When the throttle valve is situated in position other than that of an idle, the solenoid valve 16 is controlled for its opening or closing at the specified sampling period according to a state of engine operation. At rapid deceleration, when the throttle valve 2 returns to the idle position at once, the solenoid valve 16 is slowly closed at a rate of the specified time, relieving a rapid increase in intake suction pressure. Thus, overthickening in an air-fuel mixture is preventable. |
