An ECU is applied to an engine system including an engine and an MG. The ECU determines whether or not a piston is located at a position, at which compression reactive force is received, at a time point at which engine speed reaches zero after combustion of the engine is stopped. Further, in a case where the ECU determines that the piston is located at the position at which compression reactive force is received, the ECU stops the piston by applying positive torque on a positive rotation side to a crank shaft by the MG.

An engine-generator starting apparatus a three-phase winding equipped with a generating unit that rotates relative to rotation of a crankshaft of an engine, and an electronic control unit that controls supply of electric current the three-phase winding to rotate the crankshaft and start the engine. In the apparatus, the electronic control unit controls to supply first current to the three-phase winding to make the engine crankshaft of rotate reverse, the first current is of a level for stopping the piston connected to the crankshaft at a position in a compression stroke. Then it controls to supply second current (that is greater than the first current) to the three-phase winding to make the crankshaft of the engine rotate forward when a predetermined time period has elapsed, and control to ignite fuel supplied to the engine after the second current is supplied to the three-phase winding.

Methods and systems are provided for improving starting of an engine that has been stopped during humid ambient conditions. The methods and systems may reduce the possibility of starting an engine having liquid water in engine cylinders to improve engine starting. In one example, a laser is applied to a metal surface within the engine to vaporize water that may be in the engine due to condensation.

A method for controlling a mild hybrid vehicle is disclosed. The method includes determining, by a controller, whether a state of charge (SOC) of a first battery that supplies electric power to a starter-generator exceeds a reference value. The method further includes operating, by the controller, the starter-generator and a starter that is separate from the starter-generator and receives electric power from a second battery at a voltage lower than that of the first battery. A combustion engine of the mild hybrid vehicle is started using the starter-generator and the starter when it is determined that the state of charge of the first battery exceeds the reference value and it is determined that an ambient air temperature of the engine exceeds a temperature reference value.

An engine control apparatus determines that a piston is at a compression top dead center immediately before engine speed of an engine becomes zero if of the engine speed at the compression top dead center of the engine in a rotation drop period while the engine speed drops to zero after combustion of the engine is stopped. In the case where it is determined that the piston is at the compression top dead center immediately before the engine speed of the engine becomes zero, the engine control apparatus applies counter torque by the rotating electrical machine from the compression top dead center to stop the piston at a rotation angle position in a first half period of expansion process by application of the counter torque.

A vehicle has a frame, a front suspension assembly, a pair of skis, an endless drive track, and an internal combustion engine. The engine has: a motor-generator having a rotor and a stator, the motor-generator being operable in motor mode and in generator mode; a recoil starter operable to rotate a crankshaft of the engine via the rotor in a same direction as does the motor-generator in generator mode; at least one sensor adapted for sensing at least one engine parameter; and an engine control unit (ECU) receiving a signal from the at least one sensor, the ECU controlling a rotation of the crankshaft by one of the motor-generator and the recoil starter based on the signal. The vehicle also has a display for displaying a message when the crankshaft is to be rotated by the recoil starter.

A system for starting an engine of a vehicle has a fuel injector injecting fuel into a closed intake port to form an air fuel mixture. The system also includes an actuator rotating a crankshaft in a first direction to open the intake port by moving a piston within a cylinder coupled to the crankshaft. A combustion chamber defines between the cylinder and the port receiving the air fuel mixture through the intake port. The actuator rotates the crankshaft in a second direction to close the intake port. A spark plug ignites the air fuel mixture to start the engine. The engine also includes many other disclosed features.

Methods and systems are provided for improving combustion events during cold-starts of a vehicle engine, where the cold-start events include start/stop events. In one example, a method comprises spinning the engine in a reverse direction in response to an engine pull-down event where a temperature of an intake manifold of the engine is below a threshold, to heat the intake manifold by drawing exhaust system heat to the intake manifold. In this way, combustion may be improved in response to requests to start the engine, which may reduce undesired emissions and which may improve fuel economy.

A process for managing the re-start of an internal combustion engine in a Start and Stop system using an electric motor managed by an electric motor control unit (EMU), a first step of direct evaluation of the rotation regime of the crankshaft being provided by an internal combustion engine control unit (ECU) through a sensor put on the crankshaft: if the rotation regime is above a threshold corresponding to the sensor accuracy loss, in case of re-opening of the throttle valve said control unit of the combustion engine (ECU) continues to provide fuel and ignition; otherwise a crankshaft positioning step is provided by the electric motor control unit (EMU) comprising: a forward crankshaft rotation by a predetermined forward rotation angle; a detection of a possible piston stall state followed, in negative case, by an additional forward crankshaft rotation until reaching a maximum predetermined forward rotation angle; an inverse crankshaft rotation by a predetermined angle; and a detection of a possible piston stall state followed, in negative case, by an additional inverse crankshaft rotation until reaching a maximum predetermined inverse rotation angle.

An internal combustion engine includes cylinders that are divided into a first cylinder group and a second cylinder group, a cylinder reduction mechanism that holds intake valves and exhaust valves of the first cylinder group in closed states so as to establish a reduced-cylinder state. When the engine is stopped in the reduced-cylinder state, the electronic control unit provided in the engine starts the engine by ignition, by executing fuel injection and ignition in an expansion-stroke cylinder. When the first cylinder group includes an exhaust-stroke cylinder, the engine is started by ignition through fuel injection and ignition in the expansion-stroke cylinder, after a piston is moved in a reverse direction through fuel injection and ignition in the exhaust-stroke cylinder. When the first cylinder group does not include the exhaust-stroke cylinder, the engine is started by ignition, through fuel injection and ignition in the expansion-stroke cylinder and an intake-stroke cylinder.