Abstract: A fuel injection controller controls a fuel injector which injects a fuel directly into a cylinder of an engine. The fuel injection controller conducts a correction to increase a fuel injection quantity injected from the fuel injector according to a fuel-adhered quantity which is an amount of the fuel adhered to an opened intake valve. Thus, even when the fuel is adhered to the intake valve, an appropriate amount of the fuel can be injected into the cylinder.

Abstract: In a fuel injection controller that controls a fuel injection device that injects fuel directly into cylinders of an engine, a unit that detects an interference period gradually shifts an injection period of fuel from the fuel injector from a first period during which the injection period does not overlap with an initial value of the interference period, and is distant from the initial value by a given value or larger toward a second period during which the injection period overlaps with the initial value of the interference period. Then, the fuel injection controller detects an actual interference period according to a variation of an air-fuel ratio (A/F value) detected by an air-fuel ratio sensor toward lean.

Abstract: In a fuel injection controller that controls a fuel injection device that injects fuel directly into cylinders of an engine, a unit that detects an interference period gradually shifts an injection period of fuel from the fuel injector from a first period during which the injection period does not overlap with an initial value of the interference period, and is distant from the initial value by a given value or larger toward a second period during which the injection period overlaps with the initial value of the interference period. Then, the fuel injection controller detects an actual interference period according to a variation of an air-fuel ratio (A/F value) detected by an air-fuel ratio sensor toward lean.

Abstract: A fuel injection controller controls a fuel injector which injects a fuel directly into a cylinder of an engine. The fuel injection controller conducts a correction to increase a fuel injection quantity injected from the fuel injector according to a fuel-adhered quantity which is an amount of the fuel adhered to an opened intake valve. Thus, even when the fuel is adhered to the intake valve, an appropriate amount of the fuel can be injected into the cylinder.

Abstract: An element crack detecting apparatus for an oxygen sensor detects a sensor output voltage for an abnormality detection period after a fuel cut-off is started during operation of an engine. When the output voltage becomes negative, an abnormality counter is counted up. When the abnormality counter value reaches a determination value, it is determined that the element crack is present. The abnormality detection period is variably set in response to an engine rotational speed, an intake air quantity and the mixture state immediately before the fuel cut-off is effected. The determination value is variably set in response to the oxygen sensor temperature and the mixture state immediately before the fuel cut-off is effected. Further, the determination value is variably set in response to a magnitude of the negative voltage of the oxygen sensor.

Abstract: An element crack detecting apparatus for an oxygen sensor detects a sensor output voltage for an abnormality detection period after a fuel cut-off is started during operation of an engine. When the output voltage becomes negative, an abnormality counter is counted up. When the abnormality counter value reaches a determination value, it is determined that the element crack is present. The abnormality detection period is variably set in response to an engine rotational speed, an intake air quantity and the mixture state immediately before the fuel cut-off is effected. The determination value is variably set in response to the oxygen sensor temperature and the mixture state immediately before the fuel cut-off is effected. Further, the determination value is variably set in response to a magnitude of the negative voltage of the oxygen sensor.