A fuel return device couples to the high pressure side of a DI fuel system. The fuel return device provides for both continuous bleeding and occasional purging of fuel from the high pressure side to prevent issues related to vapor accumulation or heat-induced pressure increase. The fuel return device may be attached to a high pressure fuel rail in place of a sensor. The sensor may be attached the fuel return device. The fuel return device may include both an orifice that throttles the fuel flow through the fuel return device and a solenoid that allows the flow rate to be increased.

A system to control fuel-pressure of fuel delivered to a fuel-injector includes a fuel-pump, an absolute-pressure-sensor, a pressure-regulator, and a controller. The fuel-pump is operable to vary fuel-pressure of fuel output by the fuel-pump. The absolute-pressure-sensor indicates an absolute-pressure of the fuel. The pressure-regulator limits the fuel-pressure by releasing fuel output by the fuel-pump when the fuel-pressure exceeds a tank-pressure of the fuel-tank by a pressure-threshold. The controller is in communication with the absolute-pressure-sensor and the fuel-pump. The controller periodically operates the fuel-pump in a test-mode where the fuel-pressure is such that the pressure-regulator releases fuel output by the fuel-pump, estimates a barometric-pressure outside of the fuel-tank based on the absolute-pressure while the pressure-regulator is releasing fuel output by the fuel-pump into the fuel-tank, and operates the fuel-pump in a normal-mode where the fuel-pressure is controlled so the absolute-pressure corresponds to a desired-pressure that is determined based on the barometric-pressure.

A system to control fuel-pressure of fuel delivered to a fuel-injector includes a fuel-pump, an absolute-pressure-sensor, a pressure-regulator, and a controller. The fuel-pump is operable to vary fuel-pressure of fuel output by the fuel-pump. The absolute-pressure-sensor indicates an absolute-pressure of the fuel. The pressure-regulator limits the fuel-pressure by releasing fuel output by the fuel-pump when the fuel-pressure exceeds a tank-pressure of the fuel-tank by a pressure-threshold. The controller is in communication with the absolute-pressure-sensor and the fuel-pump. The controller periodically operates the fuel-pump in a test-mode where the fuel-pressure is such that the pressure-regulator releases fuel output by the fuel-pump, estimates a barometric-pressure outside of the fuel-tank based on the absolute-pressure while the pressure-regulator is releasing fuel output by the fuel-pump into the fuel-tank, and operates the fuel-pump in a normal-mode where the fuel-pressure is controlled so the absolute-pressure corresponds to a desired-pressure that is determined based on the barometric-pressure.

A method for testing a high-pressure pump, particularly a high-pressure pump which is provided to inject fuel into a combustion engine, the method including filling the high-pressure pump with a fluid prior to switching it on.

The present disclosure relates to a fuel cut apparatus capable of improving air ventilation while blocking moisture from being infiltrated thereinto by selectively opening and closing an air vent corresponding to engine starting and engine stopping. The fuel cut apparatus includes: a housing; a motor installed at one side of the housing; a rotor rotated by the motor of the housing; and a cam member rotating in association with rotation of the rotor to switch on/off a contact switch, wherein one side of the housing is provided with an air vent, and the air vent is opened or closed by the cam member.

Methods are provided for controlling a solenoid spill valve of a direct injection fuel pump, wherein the solenoid spill valve is energized and de-energized according to certain conditions. An example control strategy is provided for operating the direct injection fuel pump when fuel vapor is detected at an inlet of the direct injection fuel pump. To ensure pump effectiveness during the presence of fuel vapor, the solenoid spill valve may be maintained energized for a minimum angular duration past a top-dead-center position of a piston in the direct injection fuel pump.

The present disclosure relates to a fuel cut apparatus capable of improving air ventilation while blocking moisture from being infiltrated thereinto by selectively opening and closing an air vent corresponding to engine starting and engine stopping. The fuel cut apparatus includes: a housing; a motor installed at one side of the housing; a rotor rotated by the motor of the housing; and a cam member rotating in association with rotation of the rotor to switch on/off a contact switch, wherein one side of the housing is provided with an air vent, and the air vent is opened or closed by the cam member.

A cylinder-injection-engine control apparatus includes a fuel injection controller that executes air purge control for performing fuel injection in an intake stroke if fuel pressure is below a predetermined pressure when an engine starts. When executing the air purge control, the fuel injection controller makes a fuel injection time of an injector longer than when the fuel pressure is higher than or equal to the predetermined pressure. When executing the air purge control, if the amount of fuel in a fuel tank is larger than or equal to a predetermined amount and an integrated value of a fuel injection amount (integrated injection amount) since start of the fuel injection is larger than or equal to a predetermined value, the fuel injection controller stops the air purge control.

A fuel return device couples to the high pressure side of a DI fuel system. The fuel return device provides for both continuous bleeding and occasional purging of fuel from the high pressure side to prevent issues related to vapor accumulation or heat-induced pressure increase. The fuel return device may be attached to a high pressure fuel rail in place of a sensor. The sensor may be attached the fuel return device. The fuel return device may include both an orifice that throttles the fuel flow through the fuel return device and a solenoid that allows the flow rate to be increased.

A plunger fuel pump for an internal combustion engine includes a pump cylinder and a pump plunger that is axially displaceable in the pump cylinder. The plunger fuel pump has a seal with an annular basic structure arranged around the circumference of the pump plunger. The seal is produced by injection molding in an axial injection direction.