Systems and methods are provided for determining and correcting air/fuel imbalance between cylinders of an internal combustion engine. A deactivation strategy is determined and implemented. An evaluation is made of whether the engine is operating with an air/fuel imbalance between cylinders. When an imbalance is identified, an alternate deactivation strategy is implemented. Based on outcomes of the alternate deactivation strategy, a source cylinder of the air/fuel imbalance is identified, and fuel flow to the source cylinder is corrected.

A method for estimating damage of a component of an internal combustion engine includes receiving a fuel rate signal indicative of a fuel rate of the internal combustion engine and estimating a temperature value of the component of the internal combustion engine based on at least the received fuel rate signal. The method also includes estimating an incremental amount of damage of the component of the internal combustion engine based on the estimated temperature value of the component of the internal combustion engine, updating a cumulative amount of damage of the component of the internal combustion engine based on the estimated incremental amount of damage, and outputting a notification based on at least the cumulative amount of damage of the component of the internal combustion engine.

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 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.

A hollow first accommodating case (28) is provided on a front part of a revolving frame (5) at a position on a front side of a fuel tank (23), and a fuel supply pump (34) for supplying a fuel stored in an external fuel storage source to the fuel tank (23) is provided on the fuel tank (23) by being connected. A fuel suction port (35) for sucking the fuel toward the fuel supply pump (34) is provided in the first accommodating case (28) by being opened to an outside, and a urea water tank (25) is provided by being accommodated in the first accommodating case (28). A water supply port (25G) of a urea water is provided in the urea water tank (25) by being opened to the outside, and the fuel suction port (35) and the water supply port (25G) of the urea water are juxtaposed and arranged in the first accommodating case (28).

An outboard motor includes an engine, a fuel tank, a fuel pathway, a fuel pump, and a controller. The engine includes a fuel injector. The fuel tank includes an internal space in which fuel is stored. The fuel pathway is connected to the fuel injector and the fuel tank. The fuel pump is disposed in the fuel pathway, and supplies the fuel from the fuel tank to the fuel injector. The controller controls the fuel pump. The controller determines whether or not a start condition, indicating that air has entered the fuel pathway, is satisfied. The controller is configured or programmed to execute an air releasing control to open the fuel injector and drive the fuel pump when the start condition is satisfied.

A fuel quality rating testing system and related methodology. The system comprises a data acquisition system, comprising: (i) circuitry for receiving a time-varying signal from a pickup, the pickup for coupling to a test engine; and (ii) circuitry for determining a fuel rating in response to the time-varying signal. The fuel quality rating testing system also comprises a communications path coupled to the fuel quality rating testing system and a calibrator.

A method (50) for isolating a fault within an engine system (10) including an engine control module (40) and a diagnostics module (36) includes determining, by the engine control module (40), a plurality of parameters of the engine system (10), calculating a likelihood of the fault using a log-likelihood ratio analysis of data within the engine control module (40), and providing a plurality of fault determinations and the likelihood of each of the plurality of fault determinations using plurality of parameters and the diagnostics module (36) of the engine system (10).

Methods and systems are provided for controlling a fuel system of a vehicle to diagnose whether a fuel filter is functioning as desired. In one example, a method may include, in response to a fuel rail pressure decreasing below a threshold pressure while an engine of the vehicle is running, diagnosing whether degradation of fuel injectors or a fuel pressure regulator of the vehicle has occurred while the engine is not running. Then, only if degradation of the fuel injectors and fuel pressure regulator has not occurred, a fuel filter cleaning routine is performed.

A controller for controlling a fuel injection valve and a fuel pressure adjustment mechanism integrates a deposition amount of deposits per unit time, and estimates a deposition amount of deposits on an injection hole of the fuel injection valve. The controller causes the fuel pressure adjustment mechanism to increase a fuel pressure, when the estimated deposition amount exceeds a predetermined value, and corrects the unit deposition amount acquired by the deposition amount estimation according to the set fuel injection timing of the fuel injection valve. The controller corrects such that as compared with the unit deposition amount when the fuel injection timing is set to a first timing away from a top dead center of the piston by a first period, the unit deposition amount decreases when the fuel injection timing is set to a second timing away by a second period longer than the first period.