An internal combustion engine has one or more combustion chambers defined by one of more cylinders, corresponding pistons, and a cylinder head. A crankshaft is operatively connected to the pistons and to an electric turning machine. To start the engine, the electric turning machine rotates the crankshaft in a first direction toward a reversal point corresponding to a local maximum drag torque of the internal combustion engine, this rotation being made without rotating the crankshaft beyond the reversal point. The electric turning machine then rotates the crankshaft in a second direction opposite from the first direction, a momentum impressed on the crankshaft by compression obtained when rotating in the first direction increasing a speed of the crankshaft in the second direction. Thereafter, fuel is injected in one of the combustion chambers in which the corresponding piston first reaches a top dead center position and the fuel is ignited.

An internal combustion engine has one or more combustion chambers defined by one of more cylinders, corresponding pistons, and a cylinder head. A crankshaft is operatively connected to the pistons and to an electric turning machine. To start the engine, the electric turning machine rotates the crankshaft in a first direction toward a reversal point corresponding to a local maximum drag torque of the internal combustion engine, this rotation being made without rotating the crankshaft beyond the reversal point. The electric turning machine then rotates the crankshaft in a second direction opposite from the first direction, a momentum impressed on the crankshaft by compression obtained when rotating in the first direction increasing a speed of the crankshaft in the second direction. Thereafter, fuel is injected in one of the combustion chambers in which the corresponding piston first reaches a top dead center position and the fuel is ignited.

Methods and systems are provided for a vehicle engine having a pre-chamber ignition system. In one example, a method may include adjusting one or more of an air injection amount and a fuel injection amount to a pre-chamber of an engine based on an air injection offset and a fuel injection offset learned while discontinuing fueling to cylinders of the engine and reducing air flow through the engine. In this way, air and fuel may be more accurately provided to the pre-chamber, thereby decreasing an occurrence of pre-chamber misfire.

An electronic control unit of an internal combustion engine is configured to, when cooling fuel is supplied to a combustion chamber, calculate a target amount of supply of the cooling fuel and calculate a first upper limit injection amount that is an upper limit of an amount of fuel allowed to be injected from a second valve as the cooling fuel, when the target amount of supply is less than or equal to the first upper limit injection amount, supply the cooling fuel in the entire target amount of supply from the second valve to the combustion chamber in a first mode in which single-stage injection is performed, and, when the target amount of supply is greater than the first upper limit injection amount, supply the cooling fuel to the combustion chamber in a second mode in which the cooling fuel more easily diffuses than in the first mode.

An engine according to an embodiment includes at least one cylinder, at least one piston disposed in the at least one cylinder, a plurality of fuel injection valves disposed on the at least one cylinder, the plurality of fuel injection valves including a first fuel injection valve having a predetermined total hole area and a second fuel injection valve having a total hole area smaller than the total hole area of the first fuel injection valve, and a control device for controlling the first fuel injection valve and the second fuel injection valve according to a load of the engine.

Systems and methods for operating an engine that includes an exhaust system with a differential pressure sensor are described. In one example, output of the differential pressure sensor is compared to output of a barometric pressure sensor to determine whether or not the barometric pressure sensor is degraded. The output of the differential pressure sensor may be monitored while the engine is rotated without being fueled.

A fuel injection timing is made later and/or a fuel injection amount is made larger in a target cylinder to be subjected to explosive combustion subsequently, when a required rotation time that is a time required for rotation of an output shaft by a predetermined rotational angle is equal to or longer than a time threshold than when the required rotation time is shorter than the time threshold, at the time of predetermined startup control in which an engine and a clutch are controlled such that fuel injection and ignition in the engine are resumed from a state where the supply of fuel to the engine is cut off and the clutch is released and that the clutch is then engaged.

Provided are a method and an ICE system, including an internal combustion engine including a first and a second set of cylinders. A first and a second EGR valve control flow of exhaust gas from the cylinders to an EGR conduit. A controller controls the closing of the second EGR valve, thereby preventing flow of exhaust gas from the second set of cylinders to the EGR conduit. The second EGR valve is upstream of a turbine. The controller is configured to activate a fuel injector for late post injection of fuel into the second set of cylinders when the second EGR valve is closed, so that at least a part of the fuel that exits the second set of cylinders is uncombusted. An exhaust gas aftertreatment system receives and treats exhaust gas which is not recirculated in the EGR conduit, and includes an oxidation catalyst for combustion.

Disclosed is a four-stroke direct injection engine comprising a camshaft, and exhaust valve, and a control system. The control system is configured to change the timing of the camshaft to advance a closing of the exhaust valve, control a first fuel injection step during a compression stroke of the piston, control a second fuel injection step during a power stroke of the piston, and control a third fuel injection step, after the second fuel injection step, during the power stroke of the piston.

Some embodiments described herein relate to a method of operating a compression ignition engine. The method of operating the compression ignition engine includes opening an intake valve to draw a volume of air into a combustion chamber, closing an intake valve, and moving a piston from a bottom-dead-center (BDC) position to a top-dead-center (TDC) position in the combustion chamber at a compression ratio of at least about 15:1. The method further includes injecting a volume of fuel into the combustion chamber at an engine crank angle between about 330 degrees and about 365 degrees during a first time period. The fuel has a cetane number less than about 40. The method further includes combusting substantially all of the volume of fuel. In some embodiments, a delay between injecting the volume of fuel into the combustion chamber and initiation of combustion is less than about 2 ms.