The invention provides a vehicle engine system comprising: a fuel pump for selectively delivering fuel under high pressure; an accumulator having a first chamber for receiving an output from the fuel pump and a second chamber for receiving an oil feed, wherein as one chamber is filled up the other chamber is compressed; wherein on vehicle acceleration the fuel pump delivers fuel to a common rail fuel injection system, and on vehicle braking the fuel pump delivers fuel to the first chamber of the accumulator to thereby put the oil in the second chamber under pressure, and wherein on subsequent acceleration the oil chamber delivers an output under pressure.

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.

An example system includes a controller configured to: receive pressure information indicative of a pressure level of the pressurized fuel between an electro-mechanical valve and an engine; based on the pressure level being below a first threshold pressure, send a first signal to open the electro-mechanical valve; determine, based on the pressure information, that the pressure level is increasing upon sending the first signal; in response to the pressure level increasing, send a second signal to activate a pump; determine that the pressure level has increased to a second threshold pressure; and provide information indicating that the engine is ready for operation.

Power plants using multiple identical engine block assemblies to form multiple engines, each contributing to a common output or outputs, and each using an intake manifold, an exhaust manifold and an air rail. Air is first compressed by some engine cylinders and delivered to the air rail, and then coupled to combustion cylinders from the air rail. Compressions and combustion may be in the same cylinders, the same engine block assembly but different cylinders or in different engine block assemblies. Multiple engines in the power plants are less costly than single large engines because of the quantity of manufacture and ease of maintenance. Various embodiments are disclosed.

A method for monitoring a pressure sensor in a direct injection system including at least one common rail, a high-pressure fuel pump, a hydraulic circuit connecting the high-pressure pump to the common rail, a passive pressure-limiting valve connected to the hydraulic circuit, configured to open once the pressure in the hydraulic circuit is greater than a threshold pressure, so as to discharge the fuel, including the steps of detecting the opening of the pressure-limiting valve, measuring the pressure P.sub.MES corresponding to the time of opening of the pressure-limiting valve and comparing the measured pressure P.sub.MES to the threshold pressure P.sub.1 in order to detect a drift in the pressure sensor.

Unclogging group for unclogging a filter of a pumping group for pumping diesel to an internal combustion engine, the unclogging group (1) comprising: —a metering unit (2) supplied by diesel leaving a low pressure pump and configured for feeding in a controlled manner the diesel to a high pressure pump; the metering unit (2) comprising an electromagnetic head (4) provided with a coil (6) and a control valve (5) for controlling the diesel flow; —a filter (30) associated with the control valve (5); —a temperature sensor (34) for measuring the ambient temperature; —a control unit (31) coupled at one side to the temperature sensor (34) and at another side to the coil (6); wherein the control unit (31) is configured so that once it has received the starting input of the pumping group it compares the temperature measured by the temperature sensor (34) with a threshold value, and if the temperature measured by the temperature sensor (34) is less than the threshold value the control unit (31) commands a delay of the starting of the pumping group of a period wherein the control unit (31) supplies electrical current to the coil (6).

To reduce collision noise caused when an electromagnetic valve of a high-pressure fuel supply pump is opened. Therefore, in a control device for controlling a high-pressure fuel supply pump including: an anchor; a fixed core configured to attract the anchor with an electromagnetic force; a suction valve configured to be opened or closed when the anchor is sucked by the fixed core; and an electromagnetic force generation unit configured to generate the electromagnetic force when applied with a driving voltage, it can be achieved by providing a control unit configured to perform control to lower a driving current from a peak current before a timing at which the anchor is sucked by the fixed core and collides in an operation state where an engine is under no load and an engine rotation speed is equal to or less than a set rotation speed.

A method and system is provided of controlling a pump having a pumping element configured to provide pressurized fuel to a common rail accumulator coupled to a plurality of fuel injectors configured to inject fuel into a corresponding plurality of cylinders of an engine, comprising: receiving rail pressure values indicating a current fuel pressure in the accumulator; and responding to the received at least one rail pressure value by controlling operation of the pumping element during each potential pumping event of the pumping element to generate actual pumping events during at least some of the potential pumping events to cause the rail pressure values to remain within a desired range and to at least one of increase an overall efficiency of the pump, decrease audible noise generated by the pump, increase reliability of the pump and reduce injection pressure variations at the plurality of fuel injectors.

A control device for an internal combustion engine includes a fuel injector configured to inject fuel, a pressure increasing device that is provided upstream of the feel injector and is configured to increase the pressure of fuel supplied to the fuel injector, and an electronic control unit. The electronic control unit is configured to calculate an actual fuel injection amount based on a difference between a fuel pressure in the fuel injector in a case where the pressure increasing device increases the fuel pressure without fuel injection by the fuel injector and a fuel pressure in the fuel injector in a case where the fuel injector performs fuel injection according to the driving of the pressure increasing device.

Systems and methods for operating an engine that includes one or more fuel injectors are described. The systems and methods may characterize fuel injector operation during a time when injecting fuel may be useful to maintain balance of a catalyst to reduce engine emissions. Further, large or small amounts of fuel may be injected without affecting engine combustion.