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.

The invention relates to a method for operating a fuel injection system (1) for supplying a combustion engine of a vehicle with fuel, in which method the fuel is conveyed at high pressure with the aid of a high-pressure pump (2), fed to a high-pressure accumulator (3), and injected into a cylinder of the combustion engine with the aid of at least one injector connected to the high-pressure accumulator (3). In order to detect any damage to the drive of the high-pressure pump (3), according to the invention a) the pressure (P) in the high-pressure accumulator (3) is measured and, on the basis of the measured values, a pressure drop (?P) in the high-pressure accumulator (3) caused by an injection into a cylinder is determined, b) a maximum pressure gradient is determined during a pressure build-up phase following the injection, c) the determined pressure drop (?P) and the determined maximum pressure gradient are put into proportion.

The invention further relates to an electronic control unit for carrying out the method.

A system and method for monitoring the negative impact of a filtration system on the fuel economy of an internal combustion engine. A filter monitoring controller receives engine operating parameters of the internal combustion engine. The filter monitoring controller determines an amount of power generated by the internal combustion engine based at least in part on the engine operating parameters. The filter monitoring controller determines a filter hydraulic power consumption of a filtration system providing a fluid to the internal combustion engine. The filter monitoring controller determines a fuel economy impact of the filtration system on the internal combustion engine based at least in part on the filter hydraulic power consumption of the filtration system. The filter monitoring controller compares the fuel economy impact of the filtration system to a threshold fuel economy impact to determine whether a filter element of the filtration system requires servicing.

A method for fault diagnosis in an electronic control unit (ECU) of an engine fuel injection system. The method includes keeping the ECU and the engine fuel injection system at a set of pre-defined conditions, measuring an electrical current consumption of the ECU, and detecting a status of the ECU based on the measured electrical current consumption. Keeping the ECU and the engine fuel injection system at the set of pre-defined conditions includes switching the ECU on by switching the engine fuel injection system on, and keeping the engine fuel injection system at a not-running state. Detecting the status of the ECU based on the measured electrical current consumption includes detecting a normal status responsive to the measured electrical current consumption being in a normal electrical current range, detecting a first hardware defect in the ECU responsive to the measured electrical current consumption being in a first electrical current range, and detecting a second hardware defect in the ECU responsive to the measured electrical current consumption being in a second electrical current range.

An internal combustion engine is provided. The internal combustion engine includes a control device, and at least one injector for liquid fuel. The injector(s) can be controlled by the control device via an actuator control signal. The injector(s) include an injector outlet opening for the liquid fuel which can be closed by a needle. A sensor is also provided for measuring a measurement variable of the injector(s). The sensor is or can be in a signal connection with the control device. An algorithm is stored in the control device, which algorithm calculates a state of the injector(s) based on input variables and an injector model, compares the state calculated via the injector model with a target state, and produces a state signal in accordance therewith. The state signal is characteristic of a change in the state of the injector(s) that occurs during intended use of the injector(s) and/or an unforeseen change in the state of the injector(s). The input variables include at least the actuator control signal and the measurement values of the sensor. A method for operating such an internal combustion engine and an injector is also provided.

Various embodiments may include a method for controlling an injection process in which a fluid is conveyed to an injection element through a line system comprising: determining a time of a maximum pressure gradient caused by the injection process, based on output signals of a first pressure sensor; calculating a difference between the maximum pressure gradient and a start time; determining a propagation speed of the fluid in the line system based on the difference; determining a rigidity of the line system based on the propagation speed; determining an injected volume of the fluid based on the determined rigidity of the line system; and controlling the injection process based on the injected volume determined.

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.

Methods and systems for evaluating whether or not a fuel amount that is greater than a threshold has been release to an engine via fuel injectors when the fuel injectors are commanded off are presented. In one example, an oxygen sensor is activated and engine cranking is prevented until a pumping current of the oxygen sensor is proportionate to a concentration of oxygen sensed via the oxygen sensor so that released fuel may be observed during engine starting.

A fuel vapor purge system includes: a fuel tank; a canister; a passage component that defines an intake passage of an internal-combustion engine; a purge pump pumping vapor fuel; and a valve device having a valve object, a main part having an internal passage, an inflow port through which the vapor fuel pumped from the canister flows into the main part, an outflow port connected with the inflow port through the internal passage and being opened to the intake passage, and a leak port connected with the inflow port through the internal passage and being opened to outside of the main part. The leak port has a leak preventive structure which prevents the vapor fuel from leaking to outside when the valve device is attached to the passage component such that the vapor fuel is able to flow into the intake passage.

Various methods and systems are provided for diagnosing a condition of a fuel injector of an engine. In one example, a method for an engine includes injecting a first pulse of fuel as a first pilot injection into a first subset of cylinders of a plurality of engine cylinders, where the first pilot injection precedes a primary injection of fuel into the first subset of cylinders by a duration; correlating a first response in an engine operating parameter to the first pilot injection; and adjusting the primary injection of fuel into the first subset of cylinders based on the first response. In one example, the first pilot injection precedes the primary injection by a predefined short duration and the primary injection of fuel is adjusted within a predefined or preset upper limit and lower limit.