The present disclosure relates to an engine in which compression and expansion is performed in the same cylinder. Also disclosed is a microprocessor for controlling the state of various valves in the cylinderincluding an intake valve, a transfer valve, and an exhaust valveto cause a compression or expansion to occur. A compression tank is provided for receiving, via the transfer valve, compressed air, which may be retrieved during an expansion (combustion) cycle. Compressed air for from multiple consecutive compressions may be stored in the tank and retrieved later, including for multiple consecutive expansions. Compression and expansion are not required to occur in any fixed or predetermined pattern and the microprocessor may evaluate vehicle sensors to determine a power demand, and cause compression or expansion to occur depending on the given power demand.

An outboard motor unit includes a first outboard motor including a supercharger that is located inside a first cowling and supplies compressed air to a first engine, a second outboard motor including a second cowling and a second engine housed in the second cowling, and an air passage through which the air compressed by the supercharger of the first outboard motor is supplied to the second engine of the second outboard motor.

Methods and systems are provided for a turbocharger. In one example, a method includes adjusting one or more of a wastegate position and a position of vanes with operation of a turbocharger to reach a desired turbocharger speed via a controller. The method further includes adjusting engine operating parameters to reach the desired turbocharger speed.

Methods and systems are provided for a turbocharger. In one example, a method includes adjusting one or more of a wastegate position and a position of vanes with operation of a turbocharger to reach a desired turbocharger speed via a controller. The method further includes adjusting engine operating parameters to reach the desired turbocharger speed.

An engine control system comprises: an engine 10 capable of switching between a reduced-cylinder operation mode in which combustion is stopped in a part of a plurality of cylinders 2 and an all-cylinder operation mode in which combustion is performed in all the plurality of cylinders 2; and a PCM 50 configured to stop fuel supply to the cylinders 2 when a given fuel cut-off condition is satisfied. The PCM 50 is operable, during a transition from a state in which the engine 10 is operated in the reduced-cylinder operation mode to a state in which the fuel cut-off condition is satisfied, to stop the fuel supply to the cylinders 2 at a timing earlier than that during a transition from a state in which the engine 10 is operated in the all-cylinder operation mode to the state in which the fuel cut-off condition is satisfied.

An engine control system comprises: an engine 10 capable of switching between a reduced-cylinder operation mode in which combustion is stopped in a part of a plurality of cylinders 2 and an all-cylinder operation mode in which combustion is performed in all the plurality of cylinders 2; and a PCM 50 configured to stop fuel supply to the cylinders 2 when a given fuel cut-off condition is satisfied. The PCM 50 is operable, during a transition from a state in which the engine 10 is operated in the reduced-cylinder operation mode to a state in which the fuel cut-off condition is satisfied, to stop the fuel supply to the cylinders 2 at a timing earlier than that during a transition from a state in which the engine 10 is operated in the all-cylinder operation mode to the state in which the fuel cut-off condition is satisfied.

Disclosed is a complementary analog and digital method for controlling ignition of a gasoline engine. First, analog ignition is performed by means of an analog trigger circuit. After power has been steadily supplied to a microcontroller, the microcontroller disconnects the analog trigger circuit, starts to collect a digital trigger reference signal and turn on a digital trigger circuit, and switches to a digital signal to trigger ignition. Also disclosed is a complementary analog and digital system for controlling ignition of a gasoline engine.

Disclosed is a complementary analog and digital method for controlling ignition of a gasoline engine. First, analog ignition is performed by means of an analog trigger circuit. After power has been steadily supplied to a microcontroller, the microcontroller disconnects the analog trigger circuit, starts to collect a digital trigger reference signal and turn on a digital trigger circuit, and switches to a digital signal to trigger ignition. Also disclosed is a complementary analog and digital system for controlling ignition of a gasoline engine.

Methods and systems for operating a direct fuel injector of an internal combustion engine are described. In one example, a nozzle needle is moved in two directions to maintain fuel flow through the direct fuel injector and to reduce the possibility of the nozzle needle impacting a piezoelectric actuator. The method and system may permit long fuel injection times without causing undesirable impacts between components of a fuel injector.

Methods and systems for operating a direct fuel injector of an internal combustion engine are described. In one example, a nozzle needle is moved in two directions to maintain fuel flow through the direct fuel injector and to reduce the possibility of the nozzle needle impacting a piezoelectric actuator. The method and system may permit long fuel injection times without causing undesirable impacts between components of a fuel injector.