Methods and systems for supply of fuel for a turbine-driven fracturing pump system used in hydraulic fracturing may be configured to identify when the supply pressure of primary fuel to a plurality of gas turbine engines of a plurality of hydraulic fracturing units falls below a set point, identify a gas turbine engine of the fleet of hydraulic fracturing units operating on primary fuel with highest amount of secondary fuel available, and to selectively transfer the gas turbine engine operating on primary fuel with the highest amount of secondary fuel from primary fuel operation to secondary fuel operation. Some methods and systems may be configured to transfer all gas turbine engines to secondary fuel operation and individually and/or sequentially restore operation to primary fuel operation and/or to manage primary fuel operation and/or secondary fuel operation for portions of the plurality of gas turbine engines.

A method for operating an injector on an internal combustion engine includes the steps of: introducing a fuel into a combustion chamber of the internal combustion engine by way of the injector; capturing, for a plurality of injection events, a wear value for the injector; assigning each respective one of the wear value that is captured to a respective one of a plurality of wear value classes; determining, for each of the plurality of wear value classes, a class frequency of a plurality of the wear value that are captured and assigned to a corresponding one of the plurality of wear value classes; calculating, based on a plurality of class frequencies of the plurality of wear value classes, a total wear value for the injector; and evaluating a condition of the injector based on the total wear value.

A fuel delivery system for a vehicle having an engine configured to selectively operate between a port fuel injection (PFI) mode, a gasoline direct injection (GDI) mode, and a port and direct fuel injection (PDI) mode. The fuel delivery system includes a PFI system including plurality of PFI injectors configured to supply fuel to the engine during the PFI mode, and a GDI system including a plurality of GDI injectors configured to supply fuel to the engine during the GDI mode. A fuel system monitor is configured to monitor the fuel delivery system when operating in the PFI mode, and attribute any fuel delivery system malfunctions occurring during the PFI mode to the PFI system alone, and monitor the fuel delivery system when operating in the GDI mode, and attribute any fuel delivery system malfunctions occurring during the GDI mode to the GDI system alone.

Various embodiments of the present disclosure relate to methods and systems for measuring an injected fuel quantity during multipulse injection events in a common rail of a fuel system including a fuel pump to supply fuel to the common rail. The method, using a control unit, determines if each of the multipulse injection events in a normal operating condition includes a pilot pulse; in response to determining that the pilot pulse is included, obtaining an enforced separation value between the pilot pulse and the main pulse to emulate a single-pulse injection; while the fuel pump is temporarily shut off, performing a temporary enforced separation on a fraction of the multipulse injection events; measuring a pressure change in the common rail during the temporary enforced separation; and resuming the normal operating condition of the multipulse injection events after the pressure change is measured.

A fuel system for an internal combustion engine includes a fuel control system having a fueling control unit structured to determine a test point on a tip wear-sensitive region of a fuel injector delivery curve, and store measurements of pressure drops in a pressurized fuel reservoir caused by injections of fuel at the test point. The fueling control unit is further structured to produce an injector health signal based on the stored measurements of pressure drop. Related methodology and control logic for calculation of wear parameters for injection signal duration electronic trimming and prognostic health determinations are also disclosed.

Provided are methods and fuel injection systems implemented with a plurality of injectors coupled with a common rail, the common rail coupled with a pressure sensor, and the pressure sensor coupled with a processor. The method includes: identifying, by the processor, one of the injectors to calculate a pressure change rate of the common rail associated therewith; receiving, by the processor, pressure measurements of the common rail from the pressure sensor before and during an injection event within a measurement window; using, by the processor, a pre-injection mean pressure of the common rail to determine a rail pressure drop range that is specific to the identified injector; and calculating, by the processor, the pressure change rate associated with the identified injector based on the pressure measurements of the common rail taken during the rail pressure drop range.

A failure determination device: acquires a second digital value indicating a difference between an analog electrical output generated by inputting a first digital value incremented at a first time interval to a DA conversion circuit and a target output indicated by the first digital value at a second time interval; and determines whether the DA conversion circuit has a failure based on a signal strength in a predetermined frequency of the second digital value that is a discrete signal.

A fuel delivery system for a vehicle having an engine configured to selectively operate between a port fuel injection (PFI) mode, a gasoline direct injection (GDI) mode, and a port and direct fuel injection (PDI) mode. The fuel delivery system includes a PFI system including plurality of PFI injectors configured to supply fuel to the engine during the PFI mode, and a GDI system including a plurality of GDI injectors configured to supply fuel to the engine during the GDI mode. A fuel system monitor is configured to monitor the fuel delivery system when operating in the PFI mode, and attribute any fuel delivery system malfunctions occurring during the PFI mode to the PFI system alone, and monitor the fuel delivery system when operating in the GDI mode, and attribute any fuel delivery system malfunctions occurring during the GDI mode to the GDI system alone.

A fuel injection system includes a first fuel injector having a first electronically-controlled valve and a first injection valve configured to inject fuel when the first electronically-controlled valve is actuated. A second fuel injector has a second electronically-controlled valve and a second injection valve configured to inject fuel when the second electronically-controlled valve is actuated. The fuel injection system also includes a single fuel injector driver configured to actuate the first electronically-controlled valve and the second electronically-controlled valve.

A motor control device includes: a rotation control determination unit configured to determine whether a motor rotation control to rotate the motor fails; a parameter calculation unit configured to calculate a control failure frequency parameter having a correlation with a frequency of failure in the motor rotation control based on a determination result by the rotation control determination unit; an abnormality determination unit configured to determine whether an abnormality has occurred in the motor based on the control failure frequency parameter; and a stop suppression unit configured to suppress stop of rotation of the motor by changing a motor control parameter to perform the motor rotation control when the abnormality determination unit determines that an abnormality has occurred in the motor.