An internal combustion engine with at least one combustion chamber, at least one fuel delivery line for the delivery of fuel to at least one combustion chamber, and at least one differential pressure control valve for controlling the pressure in the at least one fuel delivery line. The at least one differential pressure control valve is configured to perform a valve opening or valve closing movement based on a pressure difference between the at least one fuel delivery line and a reference volume having a reference pressure. The internal combustion engine further includes at least one pressure relief valve, separate from the at least one differential pressure control valve, and configured to open to cause a pressure relief in the reference volume and a decrease in the reference pressure if a drop occurs in the power to be performed by the internal combustion engine.

The disclosure relates to a method for operating an internal combustion engine comprising at least two cylinders and a system for fuel injection, in which the fuel is withdrawn from a primary tank and supplied to at least one rail in a form significantly compressed compared with atmospheric pressure, and a plurality of cylinders draw the gaseous fuel from a rail used collectively, wherein, during operation of the internal combustion engine, the pressure target value of the gaseous fuel stored in the rail is controlled to or otherwise held at a constant value or a variable target value, which changes only in a small range B, irrespective of the engine operating point.

A fuel pump includes a camshaft that rotates in accordance with operation of an engine and a tappet provided in contact the camshaft. An ECU includes an angle determination unit configured to determine whether a rotation angle from a start of rotation of the camshaft when starting the engine is under a predetermined angle required for forming an oil film on a sliding portion of the tappet, and a control unit configured to, when the rotation angle from the start of rotation of the camshaft is determined to be under the predetermined angle, execute a limit process including at least one of limiting a fuel discharge pressure of the fuel pump or limiting a rotation of the camshaft.

A fuel type estimation system configured to estimate a type variable related to a type of fuel in an engine system including an engine and a fuel supply apparatus includes a storage device and an execution device. The storage device is configured to store a mapping that uses, as inputs, input variables including an engine variable related to a condition of the engine and outputs the type variable. The execution device is configured to acquire the input variables, and estimate the type variable by applying the acquired input variables to the mapping.

A method for managing the mass of fuel injected into the cylinder of an internal combustion engine fed by direct injection. The pressure and the pressure drop per unit of time are monitored (13) during the starting phase. If the pressure becomes too low (7), or if it drops too quickly (9), the mass of fuel injected on each cycle is adjusted (15) in order to maintain a high fuel pressure in the injector (37). The method can be applied, for example, in the event of low-temperature starting using any type of fuel, for example pure or mixed ethanol.

Systems and methods are provided herein for tracking degradation of a high-pressure fuel pump. In one example, a fuel system controller is configured to receive an output pressure signal from a pressure sensor, transform the output pressure signal to the frequency domain to generate frequency content of the output pressure signal, and diagnose a condition of a fuel pump based at least in part on the frequency content of the output pressure signal, the fuel pump fluidly coupled to a fuel injector via a common fuel rail, and the fuel injector is operable to inject fuel to a cylinder of an engine.

A method is disclosed of controlling operation of a fuel injector in response to measuring a quantity of fuel injected by the fuel injector from a fuel accumulator to an engine cylinder during operation of a fuel pump that delivers fuel to the accumulator, comprising: determining an average pressure of the fuel accumulator during a first time period before a fuel injection event; predicting a mass of fuel delivered to the fuel accumulator during a pumping event (Q.sub.pump); determining an average pressure of the fuel accumulator during a second time period after the fuel injection event; estimating a leakage of fuel; computing the injected fuel quantity by adding the average pressure during the first time period to Q.sub.pump, and subtracting the average pressure during the second time period and the leakage; and using the computed injected fuel quantity to control operation of the fuel injector.

A fuel pump module for a fuel tank prevents electrification of a filter within the fuel pump module. A port injection filter is housed in a filter case that is separate from a pump case that houses a port injection fuel pump. A ground bracket housed in the filter case includes a cylinder part, a first connection part, and a second connection part, which are formed as a single body and made of conductive resin. The cylinder part is disposed inside of the port injection filter. The second connection part is disposed on an opposite side of the bracket relative to the first connection part, where the first connection part is connected with the cylinder part, for the connection to the ground through a ground line. As a result, a static electricity caused by friction of fuel flowing through the filter is discharged to the ground.

A fuel supply device (1) has a valve (13) in a fuel passage between a fuel pump (3) and an engine (5). In a storage portion of an ECU (18-21) is stored a relationship between a fuel pressure and a flow rate, which are required by the engine, and voltage which is supplied to a motor (7). The ECU senses voltages V26, V27, V28 supplied to the motor from a controller (22) when the valve is opened from change points C1′, C2′, C3′ at which a characteristic between the voltage and the current which are supplied to the motor (7) is changed. Then, the ECU corrects the voltage stored in the storage portion on the basis of differences between voltages V1, V2, V5 stored in the storage portion at the change points C1, C2, C3 and the voltages V26, V27, V28 when the valve is opened. In this way, the fuel supply device can correctly control the motor in correspondence to the fuel pressure and the flow rate which are required by the engine.

A fuel injection control device of an engine is disclosed, that is provided with a fuel injection valve configured to inject a fuel according to a target pulse width into an intake passage, an intake flow rate detection unit arranged to detect a flow rate of an intake air supplied to the engine, an intake pressure detection unit arranged to detect an intake pressure in the intake passage, a fuel pressure detection unit arranged to detect a pressure of a fuel supplied to the fuel injection valve, and a pressure control unit configured to control the fuel pressure according to an engine operation state. The device is further provided with a request pulse width calculation unit configured to calculate a request pulse width on the basis of an intake flow rate detected by the intake flow rate detection unit, a fuel pressure detected by the fuel pressure detection unit, and a differential pressure between the fuel pressure and an intake pressure detected by the intake pressure detection unit, a post-correction request pulse width calculation unit configured to calculate a post-correction request pulse width through correcting the request pulse width according to the differential pressure, when injecting a fuel of which flow rate is lower than a predetermined flow rate; and a target pulse width setting unit configured to set the target pulse width on the basis of the post-correction request pulse width.