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.

Methods and systems are provided for restarting an engine when a high pressure fuel pump is degraded. In response to an indication of high pressure fuel pump degradation, fuel may be injected during an intake stroke, rather than a compression stroke, for a selected number of combustion events since the engine restart. By shifting to an intake stroke injection, the engine may be started even when sufficient fuel rail pressures are not available.

The invention relates to a control method for controlling a fuel injection system (10) of an internal combustion engine, wherein, wherein, in a fault situation of the fuel injection system (10), a camshaft angle of a camshaft (34) which drives a pump piston (32) of a high-pressure fuel pump (14) of the fuel injection system (10) is adjusted such that an injection time (tI) of injector valve (42) which injects the fuel from the fuel injection system (10) into a combustion chamber of the internal combustion engine lies in a pressure trough (50) of a pressure oscillation in a high-pressure region (16).

A method for recognizing a state change of a fuel injector of an internal combustion engine, in which fuel from a high-pressure accumulator is injected into a combustion chamber with the aid of the fuel injector. A value that is representative of a static flow rate of fuel through the fuel injector is ascertained. A state change of the fuel injector is deduced when the representative value differs from a comparative value by more than a first threshold value.

A fuel system is disclosed for use with an engine. The fuel system may have a plurality of fuel injectors, a common rail fluidly, a pump, and an outlet valve associated with the pump. The fuel system may also have a sensor configured to generate a signal indicative of a pressure of fuel in the common rail, and an electronic control module. The electronic control module may be configured to detect a zero-fueling condition, to determine a first pressure decay rate of the common rail during the zero-fueling condition while the pump is rotating, and to determine a second pressure decay rate of the common rail during the zero-fueling condition after the pump has stopped rotating. The electronic control module may also be configured to selectively generate a diagnostic flag associated with wear of the outlet valve based on the first and second pressure decay rates.

A powertrain arrangement for use with additized Dimethyl Ether (DME) fuel, the additized DME comprising DME and a lubricity additive, is provided. The powertrain arrangement includes a powertrain comprising an engine adapted for use with the additized DME fuel, a fuel tank, a conductivity sensor in the fuel tank; the conductivity sensor being arranged to transmit a signal, corresponding to a conductivity of fuel in the fuel tank, a temperature sensor in the fuel tank, the temperature sensor being arranged to transmit a signal corresponding to a temperature of the fuel in the fuel tank, and a controller configured to receive and process the conductivity signal and the temperature signal and to send a control signal to control functioning of the powertrain in response to the conductivity signal and the temperature signal. A measuring apparatus and method are also provided.

Various methods and systems are provided for health assessments of a fuel system. In one example, a fuel system includes a high-pressure fuel pump operable to increase fuel pressure from a first pressure to a second pressure, a common fuel rail fluidly coupling the high-pressure fuel pump to a plurality of fuel injectors each of which is operable to inject fuel to individual cylinders of an engine, a pressure sensor operable to detect a pressure of fuel at the common fuel rail, and a controller operable to diagnose a condition of the high-pressure fuel pump based on output from the pressure sensor.

An electronic control unit is used for an internal combustion engine that executes a specific-cylinder fuel cutoff process in which combustion in part of cylinders is stopped and combustion is continued in the remaining cylinders. The electronic control unit diagnoses whether there is a misfire anomaly in the internal combustion engine based on a misfire frequency of the internal combustion engine. The electronic control unit executes a normality restoration diagnosing process of diagnosing, in a state in which it is diagnosed that there is a misfire anomaly, that the misfire anomaly has been resolved when a measured value of the misfire frequency becomes less than or equal to a specified normality restoration determination value. The normality restoration diagnosing process is configured to not diagnose, during the execution of the specific-cylinder fuel cutoff process, that the misfire anomaly has been eliminated.

A device for a fuel system that makes a fuel available for an operation of an internal-combustion engine where the fuel system includes a fuel pump which conveys the fuel into a fuel accumulator and includes one or more injection nozzles which convey the fuel from the fuel accumulator to a working mixture of one or more cylinders of the internal-combustion engine includes an evaluation unit. The evaluation unit is configured to ascertain pressure data with respect to a physical pressure in the fuel accumulator during an operation of the fuel system at a sampling-time, ascertain a change in a reference pressure at the sampling-time with aid of a reference model of the fuel system, and detect a defect of the fuel system on a basis of the pressure data and on a basis of the change in the reference pressure.

Disclosed is a method for estimating a level of corrosion of an injector of an engine, the engine including a reference injector and at least one other injector, each injector including a tip in fluidic communication with a combustion chamber specific to each of the injectors, the respective combustion chamber of each injector also being in fluidic communication with an exhaust system of the engine. The method includes: while the engine is stopped, inhibiting a propagation of the gases from the exhaust system toward the tip of the reference injector; determining a static flow rate of an injector and a static flow rate of the reference injector; and estimating a level of corrosion of the injector by comparing the static flow rate of the injector with the static flow rate of the reference injector.