Abstract: An internal combustion engine having a combustion chamber, an intake passage and an exhaust passage, includes a fuel injector for feeding fuel to the engine and purge control apparatus for controlling the feeding of fuel vapor into the engine. The idling speed of the engine is controlled by adjusting a fuel injection operation and a purging operation while the engine is idling. The purging operation is carried out continuously while the engine is idling. A quantity of fuel which, in addition to the fuel vapor fed to the engine, is required to maintain an idling speed of the engine at a desired idling speed is calculated. The fuel injector is then controlled so that the required additional quantity of fuel is fed to the engine. When the required additional quantity of fuel becomes smaller than a predetermined minimum fuel injection amount, the fuel injection operation is stopped.

Abstract: A direct injection type engine in which an air-fuel mixture formed in a restricted region in the combustion chamber is burned in the presence of excess air when the engine is operating under a light load. A uniform air-fuel mixture is formed in the combustion chamber when the engine becomes high, a fuel vapor is purged into the intake passage of the engine from the charcoal canister, and a catalytic converter is arranged in the exhaust passage of the engine. To prevent fuel vapor from being discharged to the outside air, the purging of fuel vapor into the intake passage is stopped when the engine is operating under a light load and the temperature of the catalyzer of the catalytic converter is low.

Abstract: A fuel injection device of an engine for a vehicle having a power transmitting system connected between the engine and the drive wheel. The relative angle of torsion between the opposed ends of the power transmitting system is maintained at the converging angle of torsion determined by a required amount of fuel when a cruising operation of the engine is carried out. When the required amount of fuel is changed from a first required amount of fuel to a second required amount of fuel, a pre-injection is carried out prior to the main injection. The amount of fuel and the injection time of the pre-injection and the start time of the main injection are determined so that the relative angle of torsion becomes equal to the converging angle of torsion determined by the second required amount of fuel when the main injection is started, and that the relative angle of torsion is maintained at the converging angle of torsion determined by the second required amount of fuel after the main injection is started.