A fuel supply system includes an electronic control unit that outputs a target fuel pressure for controlling a low-pressure pump and an engine status, and a fuel pump controller (FPC) that generates a drive signal for driving the low-pressure pump based on the target fuel pressure. The FPC is configured to obtain an actual fuel pressure, to set a duty ratio and to perform a feedback control for the actual fuel pressure to follow the target fuel pressure, and to set a lower limit guard value based on the engine status. The lower limit guard setter sets a duty ratio of 0% as the lower limit guard value when the engine status indicates a stop of the engine.

Methods and systems are provided for calibrating engine port injectors. After pressurizing a low pressure fuel rail, a lift pump may be disabled and port injector variability may be correlated with a measured fuel rail pressure drop at each port injection event by sweeping injection pressure while maintaining injection voltage, and then sweeping injection voltage while maintaining injection pressure. A port injector variability map learned as a function of injection voltage and injection pressure is then transformed into a map learned as a function of injection current and injection pressure by accounting for injector variability caused due to changes in injector temperature.

A fuel pressure sensor diagnosis device includes an electronic control unit configured to drive a fuel supply device during electric traveling of a hybrid vehicle, to perform determination as to whether an output of a fuel pressure sensor is within a normal range after driving of the fuel supply device is started, and to perform a diagnosis to determine whether a malfunction has occurred in the fuel pressure sensor based on a result of the determination, the normal range being an assumed range of the output of the fuel pressure sensor in a case where the fuel pressure sensor normally functions and the fuel supply pressure is a prescribed upper limit pressure.

A control device is applied for an internal combustion engine which is provided with a high-pressure fuel pump driven by a driving shaft of the internal combustion engine to discharge a fuel pressurized in a pressurizing chamber, an accumulator accumulating a high-pressure fuel discharged from the high-pressure fuel pump, and a relief valve which is opened when a fuel pressure in the accumulator is higher than a specified pressure in order to return the fuel in the accumulator to a specified chamber where a fuel has lower pressure than a fuel in the pressurizing chamber. An idle speed of the internal combustion engine is increased to a specified speed when the fuel pressure in the accumulator has been higher than a determination pressure, which is lower than the specified pressure, for a first period or longer.

A fuel pump controller performs a feedback control of an actual fuel pressure of a feed pump to a command fuel pressure which is from an external element. The pump controller changes a gain for the feedback control to a value larger than a minimum value of the gain in response to an acceleration command information which is to accelerate a vehicle by using an internal combustion engine.

A feed pump supplies fuel to a port injection valve of an engine through low pressure fuel piping by applying a pressure to fuel. An engine ECU controls a fuel pressure which is a pressure applied to fuel by driving the feed pump. When the feed pump is driven to lower the fuel pressure, and it is determined that vapor is generated in the fuel piping, the engine ECU executes a fuel pressure control that increases the fuel pressure provided at the time of determination.

Upon receiving a request to stop an internal combustion engine, processing circuitry of a fuel supply device opens a relief valve by increasing a fuel pressure in a delivery pipe to a specified pressure or greater before stopping the internal combustion engine. The processing circuitry determines whether a fuel pressure sensor is normal based on a result of comparison between a fuel pressure in the delivery pipe detected by the fuel pressure sensor and a fuel pressure determination value after the fuel pressure in the delivery pipe starts to decrease as a result of opening the relief valve.

Systems and related methods for regulating fuel rail pressure for internal combustion engines utilizing an electronic fuel transfer pump (eFTP) on the low side to provide robust control of fuel pressure on the high side. The eFTP is in fluid communication with a low-pressure fuel circuit for providing a low-pressure fuel flow at a low pressure to a high-pressure pump. Upon failure of a fuel control valve, a pressure-responsive valve, and/or a pressure sensor impacting the high-side fuel pressure, the eFTP modulates the low-side fuel flow and/or low-side fuel pressure to mitigate damage to the engine. A controller in operative communication with the eFTP and/or one or more sensors is configured to provide a pump command to the eFTP in response to a failure condition impacting the high-side fuel pressure.

A high-pressure pump control device is applied to an internal combustion engine including a high-pressure pump supplied with fuel discharged from a low-pressure pump and an injector supplied with fuel discharged from the high-pressure pump. The high-pressure pump control device includes a prediction unit predicting whether a discharge quantity of the high-pressure pump exceeds a discharge quantity of the low-pressure pump and a restricting unit executing a discharge quantity restriction control to restrict a discharge quantity of the high-pressure pump not to exceed a predetermined value when the prediction unit predicts that a discharge quantity of the high-pressure pump exceeds a discharge quantity of the low-pressure pump.

A fuel delivery system for a vehicle having an engine configured to selectively operate between a port fuel injection (PFI) mode and a gasoline direct injection (GDI) mode includes a PFI fuel rail having a plurality of PFI injectors configured to supply fuel to the engine during the PFI mode, a GDI fuel rail having a plurality of GDI injectors configured to supply fuel to the engine during the GDI mode, a first GDI fuel supply line fluidly coupled to the GDI fuel rail, a first deactivating GDI fuel pump assembly disposed on the first GDI fuel supply line. The first deactivating GDI fuel pump assembly is configured to selectively transition between an activated mode and a deactivated mode.