Systems and methods are provided for operating a port fuel and direct injection fuel system of a rolling variable displacement engine (rVDE). In one example, a method may include selecting between controlling a lift pump of the fuel system to output fuel at a mechanically limited pressure and controlling the lift pump to output fuel at a pressure lower than the mechanically limited pressure based on whether port fuel injection is used. In this way, the lift pump may be controlled without feedback from a pressure sensor, reducing system costs, while electrical power consumption increases due to operating the lift pump to output fuel at the mechanically limited pressure are minimized due to the rVDE technology, which reduces port fuel injection usage.

A fuel supply system for an engine having a plurality of cylinders is provided, which includes a plurality of fuel injection valves configured to inject fuel into the cylinders in a given order, a first distribution pipe configured to distributingly supply fuel to some of the plurality of fuel injection valves of which the fuel injection orders are not successive in the given order, a second distribution pipe configured to distributingly supply fuel to a remainder of the plurality of fuel injection valves of which the fuel injection orders are not successive in the given order, a fuel pump part configured to discharge fuel, a first feed pipe connecting a first discharge part of the fuel pump part with the first distribution pipe, and a second feed pipe connecting a second discharge part of the fuel pump part and the second distribution pipe.

Systems and methods are provided for operating a port fuel and direct injection fuel system of a rolling variable displacement engine (rVDE). In one example, a method may include selecting between controlling a lift pump of the fuel system to output fuel at a mechanically limited pressure and controlling the lift pump to output fuel at a pressure lower than the mechanically limited pressure based on whether port fuel injection is used. In this way, the lift pump may be controlled without feedback from a pressure sensor, reducing system costs, while electrical power consumption increases due to operating the lift pump to output fuel at the mechanically limited pressure are minimized due to the rVDE technology, which reduces port fuel injection usage.

Various methods and systems are provided for health assessments of a fuel system. In one example, a fuel system includes a high-pressure fuel pump operable to increase fuel pressure from a first pressure to a second pressure, a common fuel rail fluidly coupling the high-pressure fuel pump to a plurality of fuel injectors each of which is operable to inject fuel to individual cylinders of an engine, a pressure sensor operable to detect a pressure of fuel at the common fuel rail, and a controller operable to diagnose a condition of the high-pressure fuel pump based on output from the pressure sensor.

A fuel supply system, having a low-pressure region, a high-pressure region, a pumping device, a low-pressure pump, and a high-pressure pump A pressure accumulator system is provided between the pumping device and injectors and has distributor units. Between the low-pressure pump and the high-pressure pump, a fuel distributor block is provided, which has a fuel leakage collection line for fuel leakage supplied to the fuel distributor block that has a choke and a bypass around the choke and a leakage sensor in the bypass. The choke is dimensioned such that all fuel leakage flows through the choke if the fuel leakage conducted via the fuel leakage collection line is less than a limit value, and fuel leakage flows through the bypass and across the leakage sensor if the fuel leakage conducted via the fuel leakage collection line is greater than the limit value.

Various methods and systems are provided for health assessments of a fuel system. In one example, a fuel system includes a high-pressure fuel pump operable to increase fuel pressure from a first pressure to a second pressure, a common fuel rail fluidly coupling the high-pressure fuel pump to a plurality of fuel injectors each of which is operable to inject fuel to individual cylinders of an engine, a pressure sensor operable to detect a pressure of fuel at the common fuel rail, and a controller operable to diagnose a condition of the high-pressure fuel pump based on output from the pressure sensor.

A connector block that directs fuel from an outer fuel line to an inner fuel line. The connector block includes an inlet that couples to the outer fuel line, an outlet that coupled to the inner fuel line, and a fuel accumulator fluidly coupled to the inlet and the outlet. The fuel accumulator directs the fuel from the inlet to the outlet.

Methods and systems are provided for an engine to infer fuel temperature from a measured rate of change in a pressure of a fuel passage between a low pressure fuel pump and a high pressure fuel pump during certain operating conditions, including when the low pressure fuel pump is switched off. The operation of the low pressure fuel pump may be adjusted responsively to a change in the inferred fuel temperature.

Systems and methods are provided for operating a port fuel and direct injection fuel system of a rolling variable displacement engine (rVDE). In one example, a method may include selecting between controlling a lift pump of the fuel system to output fuel at a mechanically limited pressure and controlling the lift pump to output fuel at a pressure lower than the mechanically limited pressure based on whether port fuel injection is used. In this way, the lift pump may be controlled without feedback from a pressure sensor, reducing system costs, while electrical power consumption increases due to operating the lift pump to output fuel at the mechanically limited pressure are minimized due to the rVDE technology, which reduces port fuel injection usage.

The invention relates to a fuel injection device (100) for a compression-ignition engine, comprising a first storage unit (20) which can be supplied with fuel by at least one high-pressure pump (16), the first storage unit (20) being arranged preferably inside the high-pressure pump (16), a first connecting line (26) from the first storage unit (20) to a second storage unit (30), and a second connecting line (40) from the second storage unit (30) to a fuel injector (50).