In at least some implementations, a fuel system includes a first fuel pump and a first switch adapted to be coupled to a power supply, and a second fuel pump adapted to be coupled to the power supply. A conductor is provided between a first node between the first fuel pump and the first switch and a second node to which the second fuel pump is electrically coupled or electrically communicated so that depending upon the state of the first switch power may be supplied to the first fuel pump and second fuel pump in series or in parallel.

In at least some implementations, a fuel system includes a first fuel pump and a first switch adapted to be coupled to a power supply, and a second fuel pump adapted to be coupled to the power supply. A conductor is provided between a first node between the first fuel pump and the first switch and a second node to which the second fuel pump is electrically coupled or electrically communicated so that depending upon the state of the first switch power may be supplied to the first fuel pump and second fuel pump in series or in parallel.

An electronically controlled fuel injection device that achieves reduced component count, simplified construction, and cost reduction while promoting discharge of vapor that is generated in a pressurizing chamber. With a fuel passage from a fuel intake pipe into a pressurizing chamber and a return passage that is a discharge passage for vapor generated in the pressurizing chamber, and a plunger with a prescribed reciprocating operation having a standby position set as a position enabling fuel supply and vapor discharge, the electronically controlled fuel injection device eliminates the need for an inlet check valve and promotes the discharge of vapor that is generated when fuel is supplied from the fuel intake pipe to the pressurizing chamber.

Provided is a two-stroke internal combustion engine, including: a fuel injection valve configured to supply a fuel to a crank chamber; an intake passage configured to allow only air to be sucked thereinto under a negative pressure generated when a piston is actuated; and a scavenging passage that allows communication between the crank chamber and a combustion chamber. The intake passage is branched into a first intake passage and a second intake passage. The first intake passage communicates with the crank chamber. The second intake passage communicates with the scavenging passage. The fuel injection valve is configured to inject the fuel toward at least one of the first intake passage or the crank chamber. Further, air stagnant in the scavenging passage at end of air suction serves as leading air to contribute to scavenging.

Provided is a two-stroke internal combustion engine, including: a fuel injection valve configured to supply a fuel to a crank chamber; an intake passage configured to allow only air to be sucked thereinto under a negative pressure generated when a piston is actuated; and a scavenging passage that allows communication between the crank chamber and a combustion chamber. The intake passage is branched into a first intake passage and a second intake passage. The first intake passage communicates with the crank chamber. The second intake passage communicates with the scavenging passage. The fuel injection valve is configured to inject the fuel toward at least one of the first intake passage or the crank chamber. Further, air stagnant in the scavenging passage at end of air suction serves as leading air to contribute to scavenging.

An electric fuel pump includes a housing having an oil inlet and an oil outlet, an impeller, a stator unit mounted in the housing and including a stator and a starter terminal set connected to the stator, a packaging adhesive encapsulating the stator and the starter terminal set to create an oil guide passage in communication between the oil inlet and the oil outlet, and a rotor unit mounted in the housing and including a rotor rotatably mounted in the stator and a rotating shaft mounted in the rotor and connected with the impeller. When the stator unit is electrically conducted, the rotor unit drives the impeller to draw a fuel oil into the oil guide passage. When the fuel oil goes through the oil guide passage, the stator and the starter terminal set are well protected by the packaging adhesive and prohibited from contacting the fuel oil.

A vehicle includes a residual pressure holding valve provided downstream a feed pump of a fuel to hold a pressure in a fuel pipe leading to the port injection valve. Residual pressure holding valve is opened to return the fuel in the fuel pipe to the fuel tank when the pressure in the fuel pipe exceeds a valve opening pressure, and closed when the pressure in the fuel pipe is lower than the valve opening pressure. At the time of a request to reduce a target pressure of the fuel to be supplied to the electric feed pump, a control device refrains from causing the target pressure to decrease when a load of the engine is smaller than a prescribed value, and causes the target pressure to decrease when the load of the engine is greater than the prescribed value.

A vehicle includes a residual pressure holding valve provided downstream a feed pump of a fuel to hold a pressure in a fuel pipe leading to the port injection valve. Residual pressure holding valve is opened to return the fuel in the fuel pipe to the fuel tank when the pressure in the fuel pipe exceeds a valve opening pressure, and closed when the pressure in the fuel pipe is lower than the valve opening pressure. At the time of a request to reduce a target pressure of the fuel to be supplied to the electric feed pump, a control device refrains from causing the target pressure to decrease when a load of the engine is smaller than a prescribed value, and causes the target pressure to decrease when the load of the engine is greater than the prescribed value.

Disclosed is a method for managing a piston pump using a computer of a vehicle, the pump including a guide, a piston slidably mounted in the guide, and a solenoid, suitable for moving the piston, the method including, as long as the fuel pressure in the compression chamber of the pump is below a predetermined pressure threshold, a step of the computer controlling the solenoid in order to move the piston to its high position, and a step of the computer detecting that the predetermined pressure threshold has been exceeded when the current value, measured after a predetermined period, is greater than or equal to a predetermined reference value so that the computer ceases to control the solenoid.

Disclosed is a method for managing a piston pump using a computer of a vehicle, the pump including a guide, a piston slidably mounted in the guide, and a solenoid, suitable for moving the piston, the method including, as long as the fuel pressure in the compression chamber of the pump is below a predetermined pressure threshold, a step of the computer controlling the solenoid in order to move the piston to its high position, and a step of the computer detecting that the predetermined pressure threshold has been exceeded when the current value, measured after a predetermined period, is greater than or equal to a predetermined reference value so that the computer ceases to control the solenoid.