A method performed by a control unit (11) for controlling exhaust valves (1A-6A, 1B-6B) of cylinders (1-6) in an internal combustion engine (10) is provided. The method comprise controlling (410) a number of first exhaust valves (1A-3A) for a first set of cylinders (1-3) to transfer exhaust gas to a turbine (8)) during part of an exhaust phase (Δt.sub.1) of the first set of cylinders (1-3) via a first exhaust manifold (12). Also, the method comprises controlling (420) a number of second exhaust valves (1B-3B) for the first set of cylinders (1-3) to transfer exhaust gas to an exhaust gas recirculation, EGR, conduit (9)) during part of the exhaust phase (Δt.sub.1) of the first set of cylinders (1-3) via a second exhaust manifold (7). The method further comprises controlling (430) a number of first exhaust valves (4A-6A) for a second set of cylinders (4-6) to transfer exhaust gas to the turbine (8) during part of an exhaust phase (Δt.sub.2) of the second set of cylinders (4-6) via the first exhaust manifold (12). Furthermore, the method comprises controlling (440) a number of second exhaust valves (4B-6B) for the second set of cylinders (4-6) to transfer exhaust gas to the EGR conduit (9) during a part of the exhaust phase (Δt.sub.2) of the second set of cylinders (4-6) via the second exhaust manifold (7). Here, the exhaust phase (Δt.sub.1) of the first set of cylinders (1-3) is separated in time from the exhaust phase (Δt.sub.2) of the second set of cylinders (4-6). A control unit (11), a computer program, a carrier, an internal combustion engine and a vehicle is also provided.

Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes determining a fuel injector error shape and applying a fueling correction to all injectors based on the fuel injector error shape.

An applied-ignition internal combustion engine includes first and second combustion chambers, an exhaust-gas system with an exhaust-gas purification system is disposed at the first and second combustion chambers, and an exhaust-gas manifold. An exhaust gas from a combustion of a fuel/air mixture firstly flows through the exhaust-gas manifold and subsequently flows through the exhaust-gas purification system. A first section of the exhaust-gas system from the first combustion chamber to the exhaust-gas purification system is cooled more than a second section of the exhaust-gas system from the second combustion chamber to the exhaust-gas purification system. The first combustion chamber is operated with a lean fuel/air mixture, the second combustion chamber is operated with a rich fuel/air mixture, and an overall exhaust-gas lambda value at an inlet into the exhaust-gas purification system is stoichiometric.

A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.

An internal combustion engine (1) operating in cycles, having: a plurality of piston-cylinder units (2), wherein each piston-cylinder unit (2) of the plurality of piston-cylinder units (2) is assigned an ignition device (3) which can be controlled regarding activation and selection of an ignition timing by an engine control (4), wherein a piston-cylinder unit (2), when the ignition device (3) is activated, produces a power by combustion of a gas-air mixture, which can be transmitted as a torque to a crankshaft (5) of the internal combustion engine (1) an intake stroke (6) and an exhaust stroke (7), each coupled to the plurality of piston-cylinder units (2) a supply device (8) for supplying a gas-air mixture under a boost pressure to the intake stroke (6) a signal detection device (9) for acquiring at least one signal which represents a power demand on the internal combustion engine (1) or from which a power demand on the internal combustion engine (1) can be calculated an engine control (4) for actuating actuators of the internal combustion engine (1), wherein the at least one signal can be fed to the engine control (4), and the engine control (4) is configured in a first operating mode to leave as many ignition devices (8) deactivated per cycle of the internal combustion engine in dependence on the currently present power demand, that the power of those piston-cylinder units (2), the ignition devices (8) of which are activated, results in a torque of the crankshaft (5) of the internal combustion engine (1) adapted to the currently present power demand
wherein the engine control (4) is configured to, in a second operating mode, for reducing a risk of deflagration due to unburned gas-air mixture present in the exhaust stroke (7) after a first number (N.sub.1) of cycles of the internal combustion engine (1), for a second number (N.sub.2) of cycles of the internal combustion engine (1), to have more piston-cylinder units (2) produce power per cycle by activating the assigned ignition devices (8) than would be required for the currently present power demand after the second number (N.sub.2) of cycles of the internal combustion engine (1), for a third number (N.sub.3) of cycles of the internal combustion engine (1), in dependence on a currently present power demand per cycle of the internal combustion engine (1), to have so many piston-cylinder units (2) produce power by activation of the assigned ignit

The invention relates to an internal combustion engine system (100), comprising: —an internal combustion engine (2) comprising a cylinder block (3) housing a plurality of cylinders (4), a first intake manifold (6a) connected to a first group of cylinders (4a) a second distinct intake manifold (6b) connected to a second group of cylinders (4b) and a first, respectively a second, exhaust manifold (8a, 8b) for receiving the exhaust gas emitted from the first, respectively the second, group of cylinders (4a, 4b); —an air inlet line (10); —an EGR line (20) connected to the first and second exhaust manifolds (8a, 8b); wherein the internal combustion engine system is operable in at least two operating modes, respectively a normal operating mode in which all cylinders are supplied with fuel and a regeneration operating mode, in which the cylinders of the first group of cylinders (4a) are no longer supplied with fuel, characterized in that: —the system also includes a mixing unit (30) comprising a four-way valve, said four-way valve (30) having a first inlet (31) connected to the EGR line (20), a second inlet (32) connected to the air inlet line (10), a first outlet (33) connected to the first intake manifold (6a) and a second outlet (34) connected to the second intake manifold (6b); —the four-way valve is designed so that, in said normal operating mode, the intake gases supplied to the first intake manifold (6a) and to the second intake manifold (6b) have approximately the same proportion of exhaust gas and so that, in said regeneration operating mode, the intake gas supplied to the first intake manifold (6a) only includes exhaust gas.

Methods and systems are provided for operating an engine having a plurality of cylinders that utilize oil for lubrication purposes. In one embodiment, a method for the engine may include determining if one or more conditions have been met for port heating based on one or more operating conditions of the engine, continuing current operation if the one or more conditions for port heating have not been met, and determining a souping level of the engine if the one or more conditions for port heating have been met and subsequently running port heating on a set of cylinders of the engine based on the souping level of the engine and/or the one or more conditions for port heating. The engine may be a non-EGR engine and/or a high speed diesel engine. Each cylinder of the set of cylinders may have at least one port.

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, enleaning a second set of the engine cylinders, and operating a third set of the engine cylinders at stoichiometry, exhaust gas from all of the engine cylinders 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. 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.

Systems and methods for operating an engine and controlling engine parameters over a range of ambient temperature conditions are provided. A method for an engine includes selecting one or more of an engine speed, an engine load, a base timing, and a fuel common rail pressure from a pre-calibrated engine map corresponding to a selected throttle level and modifying the one or more of the engine speed, the engine load, the base timing, and the fuel common rail pressure based on sensed environmental conditions.

A vehicle includes an exhaust passage including an exhaust cleaner, an engine coupled to the exhaust passage, fuel injection valves, and a control device. The fuel injection valves are respectively provided in cylinders of the engine and inject fuel into the cylinders. The control device performs, after main-injection, post-injection control that causes the fuel injection valves to perform post-injection. The control device determines a fuel injection amount for single-time post-injection performed by each fuel injection valve such that the fuel injection amount for the single-time post-injection is greater than a fuel injection amount when the post-injection is performed in every combustion cycle in all the cylinders. The control device performs the post-injection control such that how many times the post-injection is performed is less than how many times the post-injection is performed in a case in which the post-injection is performed in every combustion cycle in all the cylinders.