Abstract: A control apparatus for an internal combustion engine that varies the amount of lift of an intake valve is disclosed. In one embodiment, the control apparatus includes a fuel injection timing correcting device that, when lift of the intake valve is varied, corrects and varies fuel injection termination timing according to the variation of the lift of the intake valve. In another embodiment, an injection quantity correcting device is included that, when lift of the intake valve is varied, corrects and varies an injection quantity. In still another embodiment, a swirl flow generating device is included that generates a swirl flow in the cylinder. In a further embodiment, an intake valve closing timing correcting device is included that, when lift of the intake valve is varied, controls the variable valve timing mechanism so that the valve closing timing of the intake valve remains substantially constant.

Abstract: Exhaust gas temperature is raised after a cold engine start so as to rapidly activate a catalyst in an exhaust line by retarding an ignition timing at which an air-fuel mixture is fired in the engine to a point after top-dead-center during a certain time interval and promoting combustion of the air-fuel mixture, thereby accelerating the catalyst to attain its effective activation temperature after the cold engine start as quickly as possibly.

Abstract: During an air-fuel ratio feedback control based on an oxygen concentration in exhaust gases which converges an air-fuel ratio toward a target ratio suitable for a satisfactory purifying efficiency of a catalyst, the air-fuel ratio is coercively deflected so as to make a fuel mixture richer and leaner alternatively. An extent of deflection of the air-fuel ratio is set larger before the catalyst has not yet been activated sufficiently.