A method of controlling an internal combustion engine in a vehicle that includes a cylinder, a fuel system for supplying fuel to the cylinder, an air guide arranged to guide an air flow to the cylinder, and an exhaust guide arranged to guide a gas flow from the cylinder, the method including controlling the engine to provide a braking torque, the control including terminating the supply of fuel to the cylinder, restricting the flow through the exhaust guide, and restricting the flow through the air guide. The control of the engine to provide a braking torque also includes determining a value of a rotational speed of a turbocharger of the engine, and adjusting, in dependence on the determined turbocharger rotational speed value, the restriction of the flow through the air guide, and/or the restriction of the flow through the exhaust guide.

Increasing engine idle speed, combined with modulating the timing of the exhaust valve during idling, increases heat transfer from the engine to aftertreatment systems to reduce the time required for the aftertreatment system to reach a minimum temperature for efficient operation. The resultant increases in heat transfer include an increase of at least 30% in the flow rate of exhaust gases and an increase of exhaust temperature by at least 25° C.

An engine braking system includes engine braking actuators for adjusting exhaust valve timings to engine braking timings in a cylinder-number braking mode. The system further includes an engine braking controller coupled to a control switch that produces a request indicating a requested cylinder-number braking mode. The engine braking controller is structured to transition exhaust valves to the engine braking timings, determine a control term to adjust intake air pressure for varying a braking power of the engine, and to adjust geometry of an exhaust turbine based on the control term. An adjusted speed of a compressor rotated by the exhaust turbine provides a change to intake air pressure that adjusts the braking power of the engine. Different levels of braking power are provided within different cylinder-number braking modes.

Methods and systems are provided for transferring hot, compressed gases from one cylinder to another cylinder while fuel injection in both cylinders is deactivated. In one example, a method may include during a fuel shut-off event, opening a first pre-chamber injector of the first cylinder undergoing late compression or early expansion and opening a second pre-chamber injector of the second cylinder undergoing a late expansion and/or exhaust stroke or undergoing an intake stroke to allow a hot, compressed gas from the first cylinder to transfer to the second cylinder through the first and second pre-chamber injectors.

Systems and methods for heating an exhaust after treatment device and producing smooth engine torque output are described. In one example, exhaust valve opening time is adjusted to compensate for additional torque that may be generated via combusting rich air-fuel mixtures in cylinders. In addition, intake valve lift may be adjusted to compensate for additional torque that may be generated via combusting rich air-fuel mixtures in cylinders.

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.

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 for unsticking a stuck gaspath actuator are disclosed. In one embodiment, an engine operating method includes adjusting exhaust valve timing of one or more cylinders of an engine in response to an indication that a gaspath actuator is stuck in position. In this way, pressure waves in an exhaust manifold and/or an intake manifold may be generated, which may act to unstick the gaspath actuator.

A stop control device for an internal combustion engine is structured that stops the engine in a state suitable for starting and that does not cause a crank angle to change after the engine is stopped. A four-cycle internal combustion engine includes an electric valve opening and closing timing control device that sets an opening and closing timing of either or both of an intake valve and an exhaust valve. Stop control of stopping the internal combustion engine is performed when a stop signal for stopping the internal combustion engine is acquired, and post-stop phase control of displacing the opening and closing timing of the valve opening and closing timing control device in either an advancing direction or a retarding direction is performed after the internal combustion engine is stopped by the stop control.

A method to control a road vehicle provided with an internal combustion engine having a plurality of cylinders and with a servo-assisted transmission. The control method comprises the steps of: establishing a minimum spark advance which should not be exceeded in order to avoid the risk of knocking or spontaneous ignitions of the mixture; temporarily reducing, during a gear shift in the servo-assisted transmission, a torque generated by the internal combustion engine by setting an actual spark advance, which is smaller than the minimum spark advance, for one single thermodynamic cycle of each cylinder; and cancelling the injection of fuel into each cylinder in the thermodynamic cycle immediately following the thermodynamic cycle carried out with an actual spark advance smaller than the minimum spark advance.