Systems and methods are provided for diagnosing cylinders. In one example, a system includes an engine having a plurality of cylinders coupled to a crankshaft, a crankshaft speed sensor, and a controller. The controller is configured to receive a first output from the crankshaft speed sensor during nominal engine operation, receive a second output from the crankshaft speed sensor during engine operation where a fueling disturbance is introduced to a cylinder of the plurality of cylinders, indicate that the cylinder is unhealthy responsive to a difference between the first output and the second output being less than a threshold difference, and adjust one or more operating parameters of the engine in response to the indication.

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 method for operating a combustion engine performing an injection quantity correction is described. A total injection quantity per pulse of an injector is divided into a plurality of smaller equal quantity pulses. The smaller quantity pulses are implemented in ballistic injector mode. On the basis of this step, a corresponding offset correction is carried out. After the offset correction has been applied, a further correction is carried out in linear injector mode. An additional alternative for performing an injection quantity correction without additional sensor hardware is thereby provided.

A method, for a direct injection engine, for dividing a fuel injection corresponding to an engine cycle into minimum sub-injections, including: determination of a desired maximum number of sub-injections by dividing a mass of fuel to be injected during the engine cycle by a minimum injectable mass and rounding down to the nearest integer; lower bounding of the desired maximum number by an authorized maximum number of sub-injections; verification that an injection duration, for such a desired maximum number of sub-injections, is less than a duration of a possible injection window and decrementation of the desired maximum number, otherwise iteration until a positive verification.

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 method of controlling a skip-fire cylinder deactivation system of an engine system is provided. The method includes a controller deactivating a cylinder of the engine system to operate the engine system in a skip-fire mode. The method further includes determining a temperature of an injector tip nozzle associated with the cylinder and comparing the temperature of the injector tip nozzle to a threshold a temperature. In response to determining that the temperature of the injector tip nozzle is greater than the threshold temperature, the cylinder is activated by the controller.

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.

The invention relates to a method for operating a fuel supply pump of a vehicle, the vehicle comprising a combustion engine system and a gearbox, the method comprising the steps of: determining one or more operational values of at least one operational parameter of the combustion engine system; determining a reduction of a fuel provision rate to the combustion engine system; determining whether a gear step change of the gearbox is at hand, on the basis of the determined one or more operational values of the at least one operational parameter; and in case a gear step change of the gearbox is at hand, controlling operation of the fuel supply pump so as to maintain fuel supply pump speed.

Provided is a control device configured to be able to execute, in an engine which includes a DOC, a DPF, and a temperature increase unit including an exhaust throttle valve, for increasing a temperature of each of the DOC and the DPF, a forced regeneration process of removing PM deposited on the DPF by increasing the temperature of the DPF. The control device includes a flow rate estimation part configured to estimate an intake flow rate of a combustion gas sent into a cylinder of the engine. The flow rate estimation part is configured to estimate a first intake flow rate, which is the intake flow rate in the forced regeneration process, from an opening degree of the exhaust throttle valve and a first state amount which indicates an operation state of the engine including a rotation speed of the engine, based on a first relationship representing a relationship between the first intake flow rate, and the opening degree of the exhaust throttle valve and the first state amount, in the forced regeneration process.

A fuel injection control device is applied to an internal combustion engine including a fuel injection valve and causes a valve body to be in a valve open state accompanying an energization of the fuel injection valve to inject fuel. The fuel injection control device acquires a dynamic parameter. The fuel injection control device acquires an injection amount parameter. The fuel injection control device calculates, based on the dynamic parameter, a dynamic correction value. The fuel injection control device calculates, based on the injection amount parameter, an injection amount correction value. The fuel injection control device corrects a fuel injection using the dynamic correction value and the injection amount correction value.