An engine system and method for improving engine starting are disclosed. In one example, engine port throttles are adjusted differently during automatic and operator initiated engine starts. The system and method may improve engine torque control during an engine start.

To provide a controller for internal combustion engine which can suppress deterioration of the detection accuracy of the combustion state due to influence of the external disturbance component, when detecting a combustion state based on angle detection information by the crank angle sensor. A controller for internal combustion engine calculates a shaft torque in unburning; calculates an external load torque based on the shaft torque in unburning and the actual shaft torque in the vicinity of the top dead center; and in an integration crank angle interval which is set corresponding to a combustion period, calculates a subtraction value by subtracting the external load torque from the shaft torque in unburning, calculates a division value by dividing the subtraction value by the inertia moment, and calculates a combustion state index by integrating a value obtained by subtracting the division value from the crank angle acceleration.

To provide a controller and a control method for internal combustion engine which can suppress the increase in the calculation processing load for determining occurrence of the mechanical noise and occurrence of the knocking with good accuracy even when the mechanical noise occurs. When the maximum value of the strength of the component of the second frequency band in the comparison period exceeds the maximum value of the strength of the component of the first frequency band, a controller for internal combustion engine performs a second side stop determination processing that determine whether the knocking occurred, based on the strength of the component of the first frequency band, without using the strength of the component of the second frequency band.

In an embodiment, an internal combustion engine comprises a plurality of cylinders, each of the plurality of cylinders comprising at least one intake deactivator operatively connected to at least one intake valve and at least one exhaust deactivator operatively connected to at least one exhaust. An intake deactivator controller is operatively connected to the intake deactivators associated with at least two cylinders of the plurality of cylinders, and an exhaust deactivator controller is operatively connected to the exhaust deactivators associated with the at least two cylinders. In another embodiment, only a single deactivator controller is operatively connected to both the intake deactivators and to the exhaust deactivators associated with the at least two cylinders of the plurality of cylinders.

An internal combustion engine includes a twin entry type turbocharger with which a first exhaust passage and a second exhaust passage respectively communicate individually, a communication path that causes the first exhaust passage and the second exhaust passage to communicate with each other, a communication valve that opens and closes the communication path, an abnormality diagnosis device that diagnoses presence or absence of abnormality of the communication valve, a variable valve timing mechanism capable of changing a period of valve overlap of the engine, and a control device. When it is determined that abnormality of a valve closure failure of the communication valve is present, the control device operates the mechanism to reduce the valve overlap in an operating state in which the communication valve is closed, more than in a case where it is determined that abnormality of a valve closure failure of the communication valve is absent.

In a lean-burn engine equipped with a turbocharger, a responsiveness of a super-charging pressure in a lean region is enhanced by control of a valve timing of an exhaust valve while a combustion state is restrained from varying. A variable valve mechanism that can change an opening timing of the exhaust valve while keeping a closing timing of the exhaust valve constant, is included in the lean-burn engine. When a target operation point is located in the lean region, and when an actual supercharging pressure is lower than a target supercharging pressure, supercharging pressure increasing control that advances the opening timing while keeping the closing timing constant is executed by operating the variable valve mechanism.

A method may comprise: positioning a pressure control valve (PCV) at an outlet of a fuel rail; positioning a volume control valve (VCV) at an inlet of a high pressure pump; and in response to an exhaust particulate matter (PM) level deviating from a target PM level, adjusting a fuel ratio of a first fuel and a second fuel delivered to an engine, and opening one of the PCV and the VCV. In this way, the fuel oxygen content may be adjusted to maintain a PM at or below a target level without a DPF over a broad range of engine designs and operating conditions, while maintaining fuel economy.

A rocker arm mechanism capable of selectively adjusting a timing of opening or closing an intake or an exhaust valve of a plurality of exhaust valves by shifting according to a crankshaft angle and by gradually changing a maximum valve opening, or electively, allows for engine braking by decompression by opening the plurality of exhaust valves before a compression stroke in a plurality of internal combustion engines.

An apparatus for controlling an internal combustion engine is provided. An engine includes a compression release mechanism and a fuel injection valve. The compression release mechanism variably controls the opening degree of a valve member, and thereby connects the combustion chamber of the engine with at least one of the intake passage and the exhaust passage in order to release in-cylinder pressure during at least the compression stroke. A controller controls the fuel injection valve to execute coasting with the fuel cut off in which the fuel is cut off under a predetermined condition, and while executing coasting with the fuel cut off, controls the compression release mechanism to increase the opening degree of the valve member of the compression release mechanism as the speed of the engine is higher.

There is provided an internal combustion engine control apparatus having an exhaust gas recirculation amount estimation unit that learns the relationship between an exhaust gas recirculation valve opening area calculated by an exhaust gas recirculation valve opening area calculation unit and an opening degree of the exhaust gas recirculation valve and estimates an recirculation amount of exhaust gas utilized in controlling an internal combustion engine, based on the relationship between the exhaust gas recirculation valve opening area and the opening degree of the exhaust gas recirculation valve.