A method of two-step variable valve lift (VVL) malfunction avoidance learning control may include: in a two-step VVL system which is operated with a main lift and a secondary lift, verifying, by an electronic control unit (ECU), an operation avoidance area based on locking of a lock pin of a cam follower ; performing VVL operation learning, in which a failure of occurrence of the second lift is determined on the basis of a locking failure of the cam follower due to an initially set value of the operation avoidance area; and reflecting the operation avoidance area to the two-step VVL system with a corrected set value which is obtained through the VVL operation learning.

An internal combustion engine for a motor vehicle includes a combustion chamber with a gas exchange valve which is movable between an open position and a first closed position. The gas exchange valve is movable on its path from the open position in a direction of the first closed position into an intermediate position located between the open position and the first closed position and is holdable in the intermediate position at least during a part of a compression cycle of the combustion chamber following the open position of the gas exchange valve and is movable into a second closed position following the intermediate position. The part comprises more than a half of the compression cycle and less than a whole of the compression cycle. The gas exchange valve is an inlet valve via which the combustion chamber is supplyable at least with air.

In various aspects, internal combustion engines, engine controllers and methods of controlling engines are described. The engine includes a camshaft and a two cylinder sets. Cylinders in the first are deactivatable and cylinders in the second set may be fired at high or low output levels. The air charge for each fired working cycle is set based on whether a high or low torque output is selected. In some implementations, the camshaft is axially shiftable between first and second positions. First cam lobes are configured to cause their associated cylinders to intake a large air charge during intake strokes that occur when the camshaft is in the first position. Second cam lobes for cylinders in the second set cause their associated cylinders to intake a smaller air charge when the camshaft is in the second position. Second cam lobes for cylinders in the first set deactivate their associated cylinders.

A system for actuating one or more engine valves for positive power operation and engine braking operation is disclosed. In a preferred embodiment, an exhaust valve bridge and intake valve bridge each receive valve actuations from two sets of rocker arms. Each valve bridge includes a sliding pin for actuating a single engine valve and an outer plunger disposed in the center of the valve bridge to actuate two engine valves through the bridge. The outer plunger of each valve bridge may be selectively locked to its valve bridge to provide positive power valve actuation. During engine braking, application of hydraulic pressure to the outer plungers may cause the respective valve bridges and outer plungers to unlock so that all engine braking valve actuations are provided from a rocker arm acting on one engine valve through the sliding pin.

In various aspects, internal combustion engines, engine controllers and methods of controlling engines are described. The engine includes a camshaft and a two cylinder sets. Cylinders in the first are deactivatable and cylinders in the second set may be fired at high or low output levels. The air charge for each fired working cycle is set based on whether a high or low torque output is selected. In some implementations, the camshaft is axially shiftable between first and second positions. First cam lobes are configured to cause their associated cylinders to intake a large air charge during intake strokes that occur when the camshaft is in the first position. Second cam lobes for cylinders in the second set cause their associated cylinders to intake a smaller air charge when the camshaft is in the second position. Second cam lobes for cylinders in the first set deactivate their associated cylinders.

Methods, devices, controllers, and algorithms are described for operating an internal combustion engine wherein at least some firing opportunities utilize low temperature gasoline combustion (LTGC). Other firing opportunities may be skipped or utilize some other type of combustion, such as spark ignition. The nature of any particular firing opportunity is dynamically determined during engine operation, often on a firing opportunity by firing opportunity basis. Firings that utilize LTGC produce little, if any, nitrous oxides in the exhaust stream and thus, in some implementations, may require no aftertreatment system to remove them from the exhaust stream.

An internal combustion engine includes combustion chambers, each having a controllable intake valve controlling an intake port, a controllable exhaust valve controlling an exhaust port, a piston, and a fuel injector. An intake manifold is connected to the intake port of each chamber. In catalytic converter warm-up mode, each chamber is driven in four-stroke operation including a 720 crank angle degrees cycle, and opens the intake port, starting to open in 90-180 CAD, and fully closes the intake port in 180-270 CAD, opens the exhaust port during the power stroke, starting in 405-495 CAD, opens the intake port during the exhaust stroke, starting in 610-690 CAD, and fully closes the exhaust port during the exhaust stroke in 630-710 CAD. Exhaust gas is forced into the intake manifold by the piston, mixing fuel and exhaust in the intake manifold, and fully closes the intake port in 700 to 720+20 CAD.

A fuel injection control system may include a variable exhaust valve mechanism configured to primarily open an exhaust valve directly before an intake stroke in which an intake valve is opened and to secondarily open the exhaust valve during the intake stroke such that valve overlap occurs; an exhaust injector provided at an exhaust side to inject fuel; and a controller for controlling the exhaust injector such that fuel is injected through the exhaust injector before the exhaust valve is opened secondarily before or during the intake stroke.

In various aspects, internal combustion engines, engine controllers and methods of controlling engines are described. The engine includes a camshaft and a two cylinder sets. Cylinders in the first are deactivatable and cylinders in the second set may be fired at high or low output levels. The air charge for each fired working cycle is set based on whether a high or low torque output is selected. In some implementations, the camshaft is axially shiftable between first and second positions. First cam lobes are configured to cause their associated cylinders to intake a large air charge during intake strokes that occur when the camshaft is in the first position. Second cam lobes for cylinders in the second set cause their associated cylinders to intake a smaller air charge when the camshaft is in the second position. Second cam lobes for cylinders in the first set deactivate their associated cylinders.

An internal combustion engine system includes a cylinder block with a plurality of cylinders, a gas intake manifold for providing at least air to the cylinder block and an exhaust gas manifold for exiting the exhaust gas from the cylinder block, wherein the exhaust gas manifold includes at least a main exhaust gas outlet and a waste gate exhaust gas outlet, wherein the main exhaust gas outlet is connected to a main exhaust gas pipe for guiding the exhaust gas to a main exhaust gas after treatment system and the waste gate exhaust gas outlet is connected to a waste gate exhaust gas pipe, and wherein the waste gate exhaust gas pipe is reconnected to the main exhaust gas pipe upstream of the main exhaust gas after treatment system and includes at least one waste gate exhaust gas after treatment unit, such as an oxidation catalyst such as a diesel oxidation catalyst, for catalytically treating the exhaust gas streaming through the waste gate exhaust gas pipe, and to a method for increasing the temperature in an internal combustion engine system.