METHOD OF CONTROLLING INTAKE AIR AMOUNT DURING DECELERATION OF INTERNAL-COMBUSTION ENGINE

PURPOSE:To enable decrease in an amount of oil consumpted, by a method wherein a control valve, controlling an auxiliary air amount depending upon a decrease in the number of revolutions of an engine is controlled so that the area of the opening of the control valve is decreased. CONSTITUTION:A throttle valve 5 is disposed in the middle of a suction passage 3. A fast idle control valve 6 is disposed in the middle of a first air passage 8. An AIC valve 10 is located in a third air passage 8'. An HAC valve 10' and a ALV valve 10'' are situated in a second air passage 12. When the number of engine is decreased, the HAC valve 10' is closed, an AIC valve is opened, and the ALV valve 10' is closed. This prevents the occurrence of an oil rise due to the pumping effect of a piston, and permits improvement of an amount of oil consumed.