A method includes determining a value of an operational motor current limit and setting a value of a startup current limit equal to a predetermined value in excess of the value of the operational motor current limit if a set of predetermined conditions is satisfied. The method includes determining that operation of the engine has been interrupted, operating the electric motor of the variable valve timing mechanism with a current having a magnitude that is less than or equal to the startup current limit after determining that operation of the engine has been interrupted, determining that operation of the engine has resumed, and operating the electric motor of the variable valve timing mechanism with a current having a magnitude that is less than or equal to the operational motor current limit after determining that operation of the engine has resumed.

Additional approaches for the reduction of particulate emissions in gasoline engines using optimized port+direct injection are described. These embodiments include control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting and reduction of cold start emissions by use of air preheating using variable valve timing.

At a time of a startup in a non-lock state (at the time of a next startup in a case where an internal combustion engine is stopped in a non-lock state in which a VCT phase is not locked in an intermediate lock phase), it is determined whether or not the engine can be started up by most delayed startup processing. In a case where it is determined that the engine can be started up by the most delayed startup processing, the most delayed startup processing is performed. In this most delayed startup processing, the engine is cranked in a high rotation range not less than a specified rotation speed and a fuel injection and an ignition are started in a state in which the VCT phase is controlled to a vicinity of the most delayed phase (most delayed phase or within a specified range from the most delayed phase) to thereby start up the engine. In this way, at the time of the startup in the non-lock state, the engine can be quickly started up without locking the VCT phase.

A diesel engine, in particular a high-power diesel engine, which has a variable valve train including an adjusting unit for adjusting a valve opening time, a valve lift, a camshaft phase position and/or a valve steering, and a control or regulating unit for controlling the adjusting unit. The control and/or regulating unit includes at least one operational mode provided for starting the engine when the engine is at a low temperature, in which the control and/or regulating unit is provided to adjust the valve opening time, at least during a preliminary phase for at least one inlet valve, which overlaps at least with one compression stroke of an associated cylinder, and to interrupt an injection of fuel at least into the cylinder associated with the inlet valve. The invention also relates to a method for starting such a diesel engine.

A diesel engine, in particular a high-power diesel engine, having a variable valve train including an adjusting unit at least for adjusting a cam angle of at least one inlet valve, and a control or regulating unit having at least one operating mode which is for cold starting. The control and/or regulating unit is designed in an operational mode, to adjust the cam angle of the at least one inlet valve to ‘late’ by controlling the adjusting unit.

An internal combustion engine includes an intake variable lift amount mechanism that changes a maximum lift amount and valve-open period of an intake valve, and an exhaust variable lift amount mechanism that changes a maximum lift amount and valve-open period of an exhaust valve. A control unit executes a process to increase the valve-open period of the intake valve and reduce the valve-open period of the exhaust valve, when idling with a temperature of the internal combustion engine that is equal to or higher than a reference value.

Start-up of an internal combustion engine comprises maintaining one or more engine valves in an engine cylinder in a continuously open state for more than one engine cycle during engine cranking. When it is determined that an engine parameter or transmission oil pressure has reached a predetermined value, maintenance of the one or more engine valves in the continuously open state is discontinued and fuel is subsequently provided to the engine cylinder for engine start-up. In various embodiments, the engine parameter may comprise an engine temperature parameter, an engine pressure parameter or an engine electrical parameter.

The disclosure relates to a method for controlling an internal combustion engine. The internal combustion engine includes a cylinder and a piston, which runs in the cylinder, together delimiting a working chamber. The working chamber is supplied with fresh air from an intake section via an inlet valve and is connected to an exhaust manifold via exhaust valves. The internal combustion engine includes a variable valve actuation system for the actuation of the inlet valves, controlling the opening time and/or the closing time and/or the lift. A strategy for shutting down the internal combustion engine includes controlling the inlet valves of individual or all working chambers in such a way that the transfer of fresh air from the intake section to the exhaust manifold is reduced or avoided and that the drag torque of the intake combustion engine is reduced.

An internal combustion engine for a motor vehicle includes a crankshaft, a camshaft, a cylinder, a piston movably disposed in the cylinder and coupled to the crankshaft for driving the crankshaft, a first gas exchange valve which is assigned to the cylinder, a first valve clearance compensation device, where via the first valve clearance compensation device the first gas exchange valve is displaceable between a first open position and a first closed position by a first cam of the camshaft, and a control unit. The control unit is configured to align the camshaft such that the first valve clearance compensation device is pressure-loaded in the idle state of the crankshaft by a plateau area assigned to the first cam to hold the first gas exchange valve in the first open position.

An exhaust-gas purification system and method controls an internal combustion engine having at least one cylinder-piston unit operating in a overrun (drag) mode in which piston motion is induced by motion of an output shaft of a drive output unit associated with the internal combustion engine. A control device controls, for each of cylinder-piston unit, an intake fluid, an exhaust valve and fuel injection to heat an exhaust emission control device by deactivating fuel injection, passing the substantially fuel-free intake fluid into the cylinder, compressing and thereby heating the fluid in the cylinder, and passing the heated outlet fluid to the exhaust emission control device. The control device may control the amount of heating based on measurement and/or use of a temperature model of the exhaust emission control device.