Disclosed is a method for limiting fuel leakage from at least one injector in an engine of a motor vehicle, the engine being stopped and the motor vehicle ignition circuit being switched off, the injector being supplied with fuel via a fuel rail which is pressurized during operation, the pressurization persisting for a certain period when the engine has been stopped and the ignition circuit switched off, leading to leakage of fuel through the injector. The injection rail is subjected to forced cooling following the stoppage of the engine with the motor vehicle ignition circuit switched off, which is sufficient to reduce the pressure, the forced cooling continuing until the pressure in the rail is close to atmospheric pressure.

Disclosed is a method for limiting fuel leakage from at least one injector in an engine of a motor vehicle, the engine being stopped and the motor vehicle ignition circuit being switched off, the injector being supplied with fuel via a fuel rail which is pressurized during operation, the pressurization persisting for a certain period when the engine has been stopped and the ignition circuit switched off, leading to leakage of fuel through the injector. The injection rail is subjected to forced cooling following the stoppage of the engine with the motor vehicle ignition circuit switched off, which is sufficient to reduce the pressure, the forced cooling continuing until the pressure in the rail is close to atmospheric pressure.

An internal combustion engine including an intake passage fuel injection valve for injecting fuel into an intake passage and a cylinder inside fuel injection valve for injecting fuel into a combustion chamber, includes: a fuel pump pressurizing and feeding fuel, which is fed from a fuel tank, to the cylinder inside fuel injection valve; a securing part provided on a cylinder head member of the internal combustion engine to secure the fuel pump; an introducing member having heat conductivity, the introducing member connected to the fuel pump and formed with: a first introducing path for introducing fuel from the fuel tank to the fuel pump; and a second introducing path for introducing fuel from the fuel tank to the intake passage fuel injection valve; and a heat transmitting member transmitting heat between the introducing member and the securing part.

Provided is a configuration which prevents an engine from being unable to start in the state in which dew condensation occurred in a fuel injection pump and froze. The present invention relates to a fuel injection pump which is provided with a pump body and a hydraulic head and driven by an engine, and is characterized in that while the engine is in operation, the temperature of the hydraulic head is increased to a dew-point temperature or higher. Consequently, it is possible to increase the temperature of the hydraulic head and remove water in the fuel injection pump while the engine is in operation. Accordingly, the engine can be prevented from being unable to start in the state that dew condensation occurred in the fuel injection pump and froze.

Provided is a configuration which prevents an engine from being unable to start in the state in which dew condensation occurred in a fuel injection pump and froze. The present invention relates to a fuel injection pump which is provided with a pump body and a hydraulic head and driven by an engine, and is characterized in that while the engine is in operation, the temperature of the hydraulic head is increased to a dew-point temperature or higher. Consequently, it is possible to increase the temperature of the hydraulic head and remove water in the fuel injection pump while the engine is in operation. Accordingly, the engine can be prevented from being unable to start in the state that dew condensation occurred in the fuel injection pump and froze.

A fuel pump for a liquid fuel water injection system of a motor vehicle is provided. The fuel pump includes a low-pressure pump that mixes water from a water tank of the motor vehicle with liquid fuel from a fuel tank of the motor vehicle to a liquid fuel water emulsion and provides the liquid fuel water emulsion at a low pressure. A high-pressure pump is in fluid communication with the low-pressure pump and compresses the liquid fuel water emulsion from the low pressure to a high pressure for injecting the liquid fuel water emulsion into an internal combustion engine of the motor vehicle via an injection rail of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A fuel pump for a liquid fuel water injection system of a motor vehicle is provided. The fuel pump includes a low-pressure pump that mixes water from a water tank of the motor vehicle with liquid fuel from a fuel tank of the motor vehicle to a liquid fuel water emulsion and provides the liquid fuel water emulsion at a low pressure. A high-pressure pump is in fluid communication with the low-pressure pump and compresses the liquid fuel water emulsion from the low pressure to a high pressure for injecting the liquid fuel water emulsion into an internal combustion engine of the motor vehicle via an injection rail of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

Methods and systems for operating an engine that includes two fuel pumps are described. In one example, a first fuel pump may be activated or remain activated in response to an engine shutdown request so that a second fuel pump may be cooled before the first fuel pump is deactivated in response to the engine shutdown request.