A method of operating an engine with dual fuel injection capabilities to enable fuel rail over-pressure control is shown. The method comprises operating an engine cylinder with only port injection, while selectively activating and deactivating a direct injector in response to an estimated minimum fuel injection mass from the direct injector. Direct fuel injection is actuated until the minimum fuel mass injected by the direct injector has reached a lower threshold that is above an NVH limit of the engine.

Methods are provided for controlling a lift fuel pump configured to provide pressurized fuel to a direct injection fuel pump that further pressurizes the fuel to be sent to a plurality of direct injectors. Control strategies are needed that provide reliable and robust operation of the lift fuel pump by selectively providing current to the pump while optimizing energy consumption. To maintain a desired range of lift fuel pump operation, methods are proposed that involve sending current pulses to the lift fuel pump and switching to continuous current when fuel vapor is detected at an inlet of the direct injection fuel pump.

The present invention relates to a control device and a control method for an internal combustion engine including a fuel injection valve and an electric fuel pump. In stopping the internal combustion engine, the control device stops driving of the fuel pump and then fuel injection by the fuel injection valve, and increases the total amount of fuel injection by the fuel injection valve after stopping of driving of the fuel pump as the temperature of fuel in stopping the internal combustion engine decreases, thereby reducing a fuel pressure in a stop period. In this manner, fuel leakage from the fuel injection valve in the stop period can be reduced with a simple configuration.

The subject matter described here relates to a method, a controller and computer program product for controlling a fuel pump of a fuel supply system for an internal combustion engine, and a fuel supply system for an internal combustion engine. The problem to be solved is not being provided with an efficient fuel supply system capable of supplying various types of fuels without bubble formation under different environmental conditions. The method comprises the steps of measuring a pressure of a fuel in the fuel supply system by a first measuring means; measuring a temperature of the fuel by a second measuring means; measuring a physical parameter of the fuel by a third measuring means; determining, by a control unit, a fuel type based on the measured physical parameter of the fuel, a vapor pressure of the fuel based on the determined fuel type and the measured temperature, and a pressure amplitude of the measured pressure; calculating, by the control unit, a first target pressure value as a sum of the determined vapor pressure, the determined pressure amplitude and a predetermined pressure margin, and a pressure difference between the first target pressure value and a predetermined second target pressure value; and if the calculated pressure difference is greater than zero, adjusting, by the control unit, a control value for controlling an operating point of the fuel pump based on the calculated pressure difference.

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 according to the principles of the present disclosure includes a pump control module and a fuel vaporization module. The pump control module controls a first pump to deliver fuel from a fuel tank to a second pump through a fuel line. The pump control module controls the second pump to pressurize fuel from the fuel line and to deliver the pressurized fuel to a fuel rail. The fuel vaporization module determines whether fuel at an inlet of the second pump is vaporizing based on an engine operating condition. The pump control module increases an output of the first pump when fuel at the inlet of the second pump is vaporizing.

A method of operating an engine with dual fuel injection capabilities to enable fuel rail over-pressure control is shown. The method comprises operating an engine cylinder with only port injection, while selectively activating and deactivating a direct injector in response to an estimated minimum fuel injection mass from the direct injector. Direct fuel injection is actuated until the minimum fuel mass injected by the direct injector has reached a lower threshold that is above an NVH limit of the engine.

Various methods are thus provided for identifying degradation in a fuel system. In one embodiment, a method of operating a fuel system comprises applying a pulse to a fuel pump responsive to detecting that lift pump pressure corresponds to a fuel vapor pressure, ceasing application of the pulse responsive to detecting that the lift pump pressure corresponds to a relief setpoint pressure, and indicating degradation in the fuel system if the detected lift pump pressure deviates from an expected fuel rail pressure, including distinguishing among degradation in the fuel pump, a lower pressure fuel pressure sensor, a fuel rail pressure sensor, and a pressure relief valve.