The present disclosure provides a system and a method for controlling valve timing of a continuous variable valve duration engine. The method may include: classifying a plurality of control regions depending on an engine speed and an engine load; applying a maximum duration to an intake valve in a first control region; maintaining the maximum duration of the intake valve and controlling a valve overlap by using exhaust valve closing (EVC) timing in a second control region; advancing intake valve closing (IVC) timing in a third control region; controlling the IVC timing to be close to bottom dead center (BDC) in a fourth control region; controlling a throttle valve to be fully opened and generating a scavenging phenomenon in a fifth control region; and controlling the throttle valve to be fully opened and controlling the IVC timing to prevent knocking in a sixth control region.

A linear motor actuated valve assembly in which a linear motor enables electrical actuation and control of intake and exhaust valves of an internal combustion engine.

An electronic control unit sets a misfire determination threshold to a first value in the cylinder injection mode, and sets the misfire determination threshold to a second value smaller than the first value in the port injection mode, and determines that a misfire occurs in the engine when a rotation fluctuation of the engine is larger than the misfire determination threshold. In a case where the cylinder injection mode is changed to the port injection mode, when a predetermined period has elapsed from the change, the electronic control unit changes the misfire determination threshold from the first value to the second value.

An electronic control unit sets a misfire determination threshold to a first value in the cylinder injection mode, and sets the misfire determination threshold to a second value smaller than the first value in the port injection mode, and determines that a misfire occurs in the engine when a rotation fluctuation of the engine is larger than the misfire determination threshold. In a case where the cylinder injection mode is changed to the port injection mode, when a predetermined period has elapsed from the change, the electronic control unit changes the misfire determination threshold from the first value to the second value.

The present disclosure provides a system and a method for controlling valve timing of a continuous variable valve duration engine. The method includes: classifying control regions based on engine speed and load; retarding intake valve closing (IVC) timing, applying a long duration to an exhaust valve, and limiting a valve overlap in a first control region; advancing the IVC timing, applying the long duration to the exhaust valve, and controlling the valve overlap in a second control region; applying the long duration to the exhaust valve and advancing the IVC timing in a third control region; controlling a throttle valve to be fully opened and applying a short duration to the exhaust valve in a fourth control region; and controlling the throttle valve to be fully opened, applying the long duration to the exhaust valve, and retarding the IVC timing in a fifth control region.

A fuel injection system for an engine, the fuel injection system includes injectors and an electronic control unit. The injectors include needle valves; and the ECU is configured to: (i) execute partial lift injection and full lift injection with the injectors, the partial lift injection being injection during which the needle valve does not reach a fully-open state and the full lift injection being injection during which the needle valve reaches the fully-open state; (ii) operate the engine in a partial lift injection region where the injection of a required injection amount of a fuel is shared by the partial lift injection and the full lift injection; and (iii) perform the amount of correction of the required injection amount with respect to the injection amount shared by the full lift injection when the required injection amount is corrected while the engine is operated in the partial lift injection region.

A fuel injection system for an engine, the fuel injection system includes injectors and an electronic control unit. The injectors include needle valves; and the ECU is configured to: (i) execute partial lift injection and full lift injection with the injectors, the partial lift injection being injection during which the needle valve does not reach a fully-open state and the full lift injection being injection during which the needle valve reaches the fully-open state; (ii) operate the engine in a partial lift injection region where the injection of a required injection amount of a fuel is shared by the partial lift injection and the full lift injection; and (iii) perform the amount of correction of the required injection amount with respect to the injection amount shared by the full lift injection when the required injection amount is corrected while the engine is operated in the partial lift injection region.

A controller for controlling an internal combustion engine includes a valve timing adjuster, a variable valve lift mechanism and a processor. The processor controls a duty cycle of a drive signal in a selected one of control modes, thereby changing a relative rotational phase of a camshaft relative to an engine output shaft. The control modes include a specific control mode in which the duty cycle of the drive signal is adjusted to change a value of the current through a first motor. The processor performs, when changing the relative rotational phase through execution of the specific control mode, an abnormality diagnosis for the variable valve lift mechanism based on a comparison between the current value at the first motor and a reference current value. The processor sets the reference current value in accordance with a rotation angle of the output shaft of a second motor.

Methods and systems are provided for increasing engine power via partial engine enrichment and exhaust gas recirculation. In one example, a method may include enriching a first set of engine cylinders and enleaning a second, remaining set of the engine cylinders, exhaust gas from the first set and the second set producing a stoichiometric mixture at a downstream emission control device, and providing exhaust gas recirculation (EGR) to an intake passage of the engine from the first set of cylinders and not from the second set. In this way, cooling effects from the partial enrichment and the EGR enable engine air flow, and thus engine power, to be increased while an efficiency of the emission control device is maintained, thereby decreasing vehicle emissions.

Methods and systems are provided for increasing engine power via partial engine enrichment and exhaust gas recirculation. In one example, a method may include enriching a first set of engine cylinders and enleaning a second, remaining set of the engine cylinders, exhaust gas from the first set and the second set producing a stoichiometric mixture at a downstream emission control device, and providing exhaust gas recirculation (EGR) to an intake passage of the engine from the first set of cylinders and not from the second set. In this way, cooling effects from the partial enrichment and the EGR enable engine air flow, and thus engine power, to be increased while an efficiency of the emission control device is maintained, thereby decreasing vehicle emissions.