Methods and systems are provided for diagnosing degradation and/or alteration in an evaporative emission control system of a vehicle. In one example, a method may include, during a refueling, monitoring a fuel tank pressure and a fuel fill level, and detecting a presence or an absence of a fuel vapor canister of the EVAP system based on a change in fuel tank pressure with an increase in fuel level.

Methods and systems are provided for diagnosing degradation and/or alteration in an evaporative emission control system of a vehicle. In one example, a method may include, during a refueling, monitoring a fuel tank pressure and a fuel fill level, and detecting a presence or an absence of a fuel vapor canister of the EVAP system based on a change in fuel tank pressure with an increase in fuel level.

The present invention determines whether multi-stage injection control is operating normally or abnormally, and carries out a failsafe of multi-stage injection control as necessary. The present invention, which solves the problem described above, has means such as the following. The invention is provided with fuel injection valves provided respectively to each cylinder, an opened/closed valve detection means for detecting either one or both of an open valve state and a closed valve state of the fuel injection valves on the basis of the drive currents or drive voltages of the fuel injection valves, and a detection execution determination means for determining a detection execution time period including the detection start timing and the detection end timing of the open valve state or closed valve state; detection interference such as overlapping detection with another cylinder and overlapping of open valve detection and closed valve detection being preventable, and risks such as erroneous detection being reducible.

A fuel management system to improve accuracy of calibration data to convert an output value of a fuel gauge into a remaining amount of fuel in a fuel tank includes a fuel tank mounted on a hull of a marine vessel, a fuel gauge to measure a liquid level position of fuel in the fuel tank, and a controller configured or programmed so that in a range where an output value of the fuel gauge changes, measurement reference points are set based on the output value of the fuel gauge. When supplying fuel to the fuel tank, the controller is configured or programmed to obtain calibration data showing a relationship between the output value of the fuel gauge and a remaining amount of the fuel in the fuel tank by comparing an amount of fuel supplied to the fuel tank at each of the measurement reference points and the output value of the fuel gauge at each of the measurement reference points.

A fuel filter monitoring method includes receiving pressure signals that are indicative of a pressure drop across at least one fuel filter of a fuel supply system configured to supply fuel to at least one fuel injector of an internal combustion engine and receiving a condition signal indicative of a condition of a fuel supply system, the condition signal being generated by one or more of a geographic location sensor, an altitude sensor, and/or a fuel temperature sensor. The method includes estimating a remaining life of at least one fuel filter of the fuel supply system based on the pressure signal and the condition signal and outputting a notification indicative of the estimated remaining life.

A fuel management system to improve accuracy of calibration data to convert an output value of a fuel gauge into a remaining amount of fuel in a fuel tank includes a fuel tank mounted on a hull of a marine vessel, a fuel gauge to measure a liquid level position of fuel in the fuel tank, and a controller configured or programmed so that in a range where an output value of the fuel gauge changes, measurement reference points are set based on the output value of the fuel gauge. When supplying fuel to the fuel tank, the controller is configured or programmed to obtain calibration data showing a relationship between the output value of the fuel gauge and a remaining amount of the fuel in the fuel tank by comparing an amount of fuel supplied to the fuel tank at each of the measurement reference points and the output value of the fuel gauge at each of the measurement reference points.

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.

Methods and systems are provided for a fuel injector diagnostic. In one example, a method may include modifying an injection pattern to determine a relative fuel mass error of an injector. A fuel injector correction may be determined based the relative fuel mass error.

Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes adjusting port-fuel injecting parameters in response to a learned direct injector fueling error.

A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.