| 摘要 |
PURPOSE:To suppress generation of harmful gases during deceleration of a car, bu compulsorily holding a solenoid valve open during deceleration as well as putting the low-speed fuel supply system in reduced fuel supply or shut-off state. CONSTITUTION:A suction manifold is in communication with the neighborhood of the air discharge hole of an air filter 2 through a secondary air passage 12, and in the midway thereof a neg. pressure control valve 13 and a solenoid operated valve 20 are installed. During deceleration of the car, a solenoid operated valve 10 is put in operation in accordance with fuel cut signals so as to block a slow fuel passage 8. A drive circuit 22 opens said solenoid valve 20 by applying current to a solenoid 20a in accordance with Rich signal, and the secondary air in an amount corresponding to the neg. pressure at the suction manifold given by the above-mentioned neg. pressure control valve 13 is supplied to the engine 4 along with the suction air, which has passed a throttle valve 5. Now the air-to-fuel ratio of the mixture gas is controlled in the Lean direction. |
