A high-pressure pump is configured to pressurize fuel. The high-pressure pump includes a relief valve device that is placed in a relief passage, which has one end part connected to a discharge passage in a housing while another end part of the relief passage is configured to be communicated with a suction passage in the housing. The discharge passage is configured to conduct the fuel, which is pressurized in and discharged from a pressurizing chamber. The relief valve device is configured to enable or limit a flow of the fuel between one side of the relief passage, at which the discharge passage is located, and another side of the relief passage, which is opposite to the discharge passage, at a valve opening time or a valve closing time of the relief valve device.

Methods and systems are provided for a gear driven diesel fuel injection pump of an engine. In one example, a front end of an engine includes an idler gear in meshing engagement with a first end of a crankshaft and a fuel pump drive gear in meshing engagement with the idler gear. The front end of the engine may further include a fuel pump, where an input shaft of the fuel pump is directly coupled to the fuel pump drive gear.

Methods and systems are provided for a gear driven diesel fuel injection pump of an engine. In one example, a front end of an engine includes an idler gear in meshing engagement with a first end of a crankshaft and a fuel pump drive gear in meshing engagement with the idler gear. The front end of the engine may further include a fuel pump, where an input shaft of the fuel pump is directly coupled to the fuel pump drive gear.

Methods and systems are described for a fuel system in an engine comprising two lift pumps. One example method comprises deactivating one of a first lift pump and a second lift pump if fuel fill level in a common reservoir decreases below a threshold fill level, wherein the first lift pump and the second lift pump are positioned in the common reservoir. By deactivating one of the two lift pumps, the two lift pumps may be protected from degradation due to fuel starvation.

Methods and systems are described for a fuel system in an engine comprising two lift pumps. One example method comprises deactivating one of a first lift pump and a second lift pump if fuel fill level in a common reservoir decreases below a threshold fill level, wherein the first lift pump and the second lift pump are positioned in the common reservoir. By deactivating one of the two lift pumps, the two lift pumps may be protected from degradation due to fuel starvation.

A fuel pump includes a body portion housing a fuel pump assembly configured to receive a rotational input and generate fuel flows, a drive shaft extending into the body portion with a pump gear coupled to the drive shaft, and a pilot portion annularly disposed about the drive shaft adjacent to the body portion. A fuel pump adapter is removably and annularly disposed about the pilot portion and configured to engage a gear housing within a fuel pump aperture.

A fuel pump includes a body portion housing a fuel pump assembly configured to receive a rotational input and generate fuel flows, a drive shaft extending into the body portion with a pump gear coupled to the drive shaft, and a pilot portion annularly disposed about the drive shaft adjacent to the body portion. A fuel pump adapter is removably and annularly disposed about the pilot portion and configured to engage a gear housing within a fuel pump aperture.

A method for operating a fluid delivery system of a vehicle powerplant is provided. The method includes sampling a fluid pressure in a port injection section of the fluid delivery system, determining if an isolation valve positioned upstream of a direct injection pump is degraded based on the fluid pressure, where the isolation valve separates the port injection section from a direct injection section, and when it is determined that the isolation valve is degraded, indicating said degradation of the isolation valve.

A method for operating a fluid delivery system of a vehicle powerplant is provided. The method includes sampling a fluid pressure in a port injection section of the fluid delivery system, determining if an isolation valve positioned upstream of a direct injection pump is degraded based on the fluid pressure, where the isolation valve separates the port injection section from a direct injection section, and when it is determined that the isolation valve is degraded, indicating said degradation of the isolation valve.

A fuel supply device supplying a fuel stored in a fuel tank to an engine includes a low-pressure pump configured to feed the fuel, a high-pressure pump configured to compress the fuel discharged from the low-pressure pump and to feed to the engine, a first low-pressure passage member configured to define a first fuel passage from the low-pressure pump to the high-pressure pump, and a second low-pressure passage member configured to define a second fuel passage branched from the first fuel passage at a low-pressure junction portion and joining the first fuel passage at a low-pressure confluence portion, wherein the first fuel passage and the second fuel passage are different in at least one of (i) temperatures of the fuels that flow through the fuel passages and (ii) passage lengths of the fuel passages from the low-pressure junction portion to the low-pressure confluence portion.