Systems and methods for operating an internal combustion engine that is included in a hybrid vehicle are described. In one example, the internal combustion engine is operated in a two stroke mode during cold starting to increase mass flow to an electrically heated catalyst so that engine emissions may be reduced.

A system includes an aftertreatment system heater of an exhaust aftertreatment system coupled to an engine A controller coupled to the aftertreatment system heater is configured to determine a condition of an exhaust gas from an engine and compare the condition to a predefined threshold. If the condition of the exhaust gas does not meet the predefined threshold, the controller is configured to determine whether an engine operating condition is met for activating a cylinder deactivation operating mode for the engine. If the engine operating condition is met, the controller is configured to operate the engine in the cylinder deactivation operating mode by deactivating a cylinder of a plurality of cylinders. If the engine operating condition is not met, the controller is configured to activate the aftertreatment system heater to heat the exhaust gas.

A control device for an internal combustion engine is configured to carry out a lean combustion of which excess air factor is 2.0 or more by injecting fuel for creating a homogeneous air-fuel mixture from a first fuel injection valve into a combustion chamber of an engine main body, injecting ignition fuel for creating an ignition air-fuel mixture near an electrode portion of a spark plug from a second fuel injection valve, and igniting the ignition air-fuel mixture, and when occurrence of knocking is detected based on a detection value of a knock sensor during the lean combustion, apply retard correction to each of an ignition timing of the spark plug and an injection timing of the ignition fuel set corresponding to an engine operating state, and apply increase correction to an injection amount of the ignition fuel.

An ECU has a fuel pressure sensor that detects fuel pressure inside of a common rail. The ECU detects the fuel pressure at a predetermined frequency and calculates a drop amount of the fuel pressure in accordance with fuel injection by fuel injectors based on the detected fuel pressure. The ECU acquires a fluctuation amount of a fuel injection amount of each of the fuel injectors based on the drop amount of the fuel pressure and learns an injection characteristic of each of the fuel injectors, the injection characteristic indicating a correlation between the fuel injection amount and the fluctuation amount of the fuel injection. In a case in which a detection timing of the fuel pressure is within a fuel injection period of a predetermined fuel injector, the ECU disallows the learning of the injection characteristic using the fuel pressure detected in the fuel injection period.

An electronic control unit of an internal combustion engine is configured to control the fuel injection valve and to control a spark plug if necessary such that fuel is combusted by pre-mixture compression ignition combustion or flame propagation combustion. The electronic control unit is configured to perform homogeneous combustion in a flame ignition operation range when switching failure has not occurred, the homogeneous combustion being combustion in which fuel homogeneously diffused into the combustion chamber is ignited using the spark plug and is combusted by flame propagation combustion. The electronic control unit is configured to perform spray-guided stratified combustion in a second operation range when the switching failure has occurred, the spray-guided stratified combustion being combustion in which fuel in the fuel injection path is ignited using the spark plug and is combusted by the flame propagation combustion.

A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to calculate a target combustion condition according to the fuel ratio. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition.

A control apparatus is disclosed for operating a fuel injector of an internal combustion engine. The control apparatus includes an Electronic Control Unit configured to: perform a first calculation task in order to calculate a set of Start Of Injection values (SOI.sub.i) of a train of injections, calculate an angular position (DIAngPos) of the crankshaft defining the start of a second calculation task, and perform the second calculation task in order to calculate a set of values (ET.sub.i) of the energizing time of the injections of the train. The angular position (DIAngPos) is calculated as a function of the Start Of Injection value (FirstSOI) of the first injection of the train as calculated by the first calculation task.

A method for operating an internal combustion engine, the method including the steps of: (a) actuating an injector to introduce a pre-injection amount of a fuel into a combustion chamber of the internal combustion engine; (b) determining, for an operating cycle of the combustion chamber in which the injector was actuated in the step (a), a pressure gradient characteristic value which is characteristic of a combustion chamber pressure gradient in the combustion chamber; (c) repeating the steps (a) and (b) a plurality of times; (d) determining a skew of a distribution of a plurality of pressure gradient characteristic values determined in the step (c); and (e) changing or maintaining an actuation of the injector depending on the skew determined in the step (d).

A fuel injection strategy and ignition timing for a spark-ignition direct fuel injection engine are selected in response to monitored engine load in relation to a plurality of load regions. This includes selecting a preferred ignition timing based upon the engine load, and selecting a first fuel injection event that is executed post-ignition, wherein the first fuel injection event delivers a set fuel mass at a preset timing relative to the preferred timing for the spark ignition event regardless of the engine load. A first pre-ignition fuel injection event is selected, and includes a second fuel mass being injected at a second fuel injection timing, wherein an end-of-injection timing of the first pre-ignition fuel injection event is at a preset timing relative to the preferred ignition timing regardless of the engine load, and wherein the second fuel mass is determined in relation to the engine load.

An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.