Methods and systems are provided for engine braking in a vehicle. In one example, a method may include deactivating fueling to at least one cylinder of an engine, increasing an air mass provided to the engine via an electric boosting device, and adjusting an exhaust valve opening timing of the at least one cylinder in response to a request for engine braking. In this way, an amount of engine braking torque may be increased with reduced wear to engine system components.

A method of controlling a skip-fire cylinder deactivation system of an engine system is provided. The method includes a controller deactivating a cylinder of the engine system to operate the engine system in a skip-fire mode. The method further includes determining a temperature of an injector tip nozzle associated with the cylinder and comparing the temperature of the injector tip nozzle to a threshold a temperature. In response to determining that the temperature of the injector tip nozzle is greater than the threshold temperature, the cylinder is activated by the controller.

A method of controlling a skip-fire cylinder deactivation system of an engine system is provided. The method includes a controller deactivating a cylinder of the engine system to operate the engine system in a skip-fire mode. The method further includes determining a temperature of an injector tip nozzle associated with the cylinder and comparing the temperature of the injector tip nozzle to a threshold a temperature. In response to determining that the temperature of the injector tip nozzle is greater than the threshold temperature, the cylinder is activated by the controller.

An internal combustion engine operates so that it delivers zero or negative torque. The engine operates in either a deceleration cylinder cut off (DCCO) mode or skip cylinder compression braking mode. In the skip cylinder compression braking mode, selected working cycles of selected working chambers are operated in a compression release braking mode. Accordingly, individual working chambers are sometimes not fired and sometimes operated in the compression release braking mode while the engine is operating in the skip cylinder compression braking mode.

An internal combustion engine operates so that it delivers zero or negative torque. The engine operates in either a deceleration cylinder cut off (DCCO) mode or skip cylinder compression braking mode. In the skip cylinder compression braking mode, selected working cycles of selected working chambers are operated in a compression release braking mode. Accordingly, individual working chambers are sometimes not fired and sometimes operated in the compression release braking mode while the engine is operating in the skip cylinder compression braking mode.

Systems and methods for operating an engine and a torque converter are presented. In one example, slip of a torque converter is adjusted via at least partially closing or opening a torque converter clutch in response to vehicle vibration. The vehicle vibration may be based on road surface conditions and an actual total number of operating cylinders of the engine.

An internal combustion engine system includes an internal combustion engine, a controller, and an increased brake load event communicator. The internal combustion engine includes a first cylinder and a first cylinder deactivation prevention mechanism. The first cylinder is configured to be selectively activated and deactivated. The first cylinder deactivation prevention mechanism is configured to selectively prevent the first cylinder from being deactivated. The controller is communicable with the first cylinder deactivation prevention mechanism. The controller includes an increased brake load event detection module that is configured to selectively control the first cylinder deactivation prevention mechanism to prevent the first cylinder from being deactivated. The increased brake load event communicator is communicable with the controller. The increased brake load event detection module is configured to control the first cylinder deactivation prevention mechanism to prevent the first cylinder from being deactivated based on a communication from the increased brake load event communicator.

An internal combustion engine system includes an internal combustion engine, a controller, and an increased brake load event communicator. The internal combustion engine includes a first cylinder and a first cylinder deactivation prevention mechanism. The first cylinder is configured to be selectively activated and deactivated. The first cylinder deactivation prevention mechanism is configured to selectively prevent the first cylinder from being deactivated. The controller is communicable with the first cylinder deactivation prevention mechanism. The controller includes an increased brake load event detection module that is configured to selectively control the first cylinder deactivation prevention mechanism to prevent the first cylinder from being deactivated. The increased brake load event communicator is communicable with the controller. The increased brake load event detection module is configured to control the first cylinder deactivation prevention mechanism to prevent the first cylinder from being deactivated based on a communication from the increased brake load event communicator.

A first intake manifold is connected to a first group of cylinders, a second distinct intake manifold is connected to a second group of cylinders and a first, respectively a second, exhaust manifold for receiving the exhaust gas emitted from the first, respectively the second, group of cylinders. An EGR line is connected to the first and second exhaust manifolds. A mixing unit includes a four-way valve having a first inlet connected to an air line, a second inlet connected to the EGR line, a first outlet connected to the first intake manifold and a second outlet connected to the second intake manifold. The first inlet is connected to the air line, the second inlet is connected to the EGR line. The first outlet and said second outlet form a substantially X-shape. The first inlet and said second inlet are coaxial. The first outlet and second outlet are coaxial such that the first inlet is diagonally facing the second inlet and the first outlet is diagonally facing the second outlet.

The invention relates to an internal combustion engine system. The system includes a mixing unit comprising a four-way valve. The four-way valve having a first inlet connected to the EGR line, a second inlet connected to the air inlet line, a first outlet connected to the first intake manifold and a second outlet connected to the second intake manifold. The four-way valve is designed so that, in said normal operating mode, the intake gases supplied to the first intake manifold and to the second intake manifold have approximately the same proportion of exhaust gas and fresh air and so that, in said cylinder deactivation mode, the intake gas supplied to the first intake manifold only includes exhaust gas and the fresh air is directed exclusively to the second intake manifold.