A spark plug electrode wearing rate estimating method for a spark plug in which spark discharge occurs between two electrodes by application of voltage generated by an ignition coil, includes the step of estimating a wearing rate of a first electrode in one spark discharge based on a temperature of the first electrode, and a spark discharge voltage and supply energy from the ignition coil. The first electrode contains any one of Ir, Ru, W, and Ni as a main component.

A position sensor malfunction determination apparatus includes a determination unit and a controller. The determination unit is configured to perform a determination relating to electricity supply failure in a position sensor. The controller is configured to perform a fail-safe control. The determination unit is configured to determine whether each of conditions (A) and (B) is established, in a preliminarily determination before occurrence of the electricity supply failure in the position sensor is finally determined. The determination unit is configured to determine that the position sensor has a probability of the electricity supply failure when both the conditions (A) and (B) are determined to be established in the preliminarily determination. The controller is configured to execute, when the determination unit determines that the position sensor has the probability of the electricity supply failure, the fail-safe control before the occurrence of the electricity supply failure in the position sensor is finally determined.

A system is provided that includes one or more sensors configured to monitor operating parameters of engine components and a controller. The controller is programmed to perform operations that include displaying test details on a display screen that are specific to a selected test to be performed on the engine components. The test details include pre-conditional parameters of the engine components that are necessary prior to starting the selected test. The operations also include receiving the monitored operating parameters of the engine components from the one or more sensors and determining whether the monitored operating parameters satisfy the pre-conditional parameters. The operations further include, responsive to receiving an indication to start the selected test and determining that the measured operating parameters satisfy the pre-conditional parameters, performing the selected test on the engine components.

A diagnostic device incorporates a processor and a memory and diagnoses a failure related to a fuel injection system for an engine whose air-fuel ratio of is feedback-controlled. The diagnostic device includes a calculation unit which calculates a corrected value of a fuel injection amount according to a difference between a target value and a measured value of the air-fuel ratio. The diagnostic device includes a setting unit which sets a mask period in which a failure diagnosis is suspended, according to the corrected value upon switchover of a fuel injection mode. The diagnostic device includes a diagnostic unit which does not carry out the diagnosis in the mask period and carries out the diagnosis outside the mask period.

A method of determining a learning area of injector opening duration according to the present exemplary embodiment divides an entire control area for controlling opening duration of an injector into a learning map area which needs learning and a reference map area which uses an already prepared reference map as is without learning, and a period from a minimum injection time to a minimum linear injection time of the injector is determined as the learning map area, and a period from the minimum linear injection time to a maximum injection time is determined as the reference map area.

A failure detection apparatus for fuel systems of an engine includes a first failure determiner executing, while the engine is in each of a first injection form and a second injection form, a failure determination process on the corresponding fuel system, a second failure determiner executing, when the first failure determiner determines occurrence of a failure in one of the injection forms, a failure determination process on the fuel system corresponding to the other injection form, a failure locator determining whether or not the failure has occurred, for each of the fuel systems responsible for the first and second injection forms, based on a result by the second failure determiner, and a purge process prohibiter prohibiting execution of a purge process for the engine. The second failure determiner causes the purge process prohibiter to prohibit execution of the purge process, when executing the failure determination process on the fuel system.

A control method for an internal combustion engine including: setting a target valve opening degree of the first throttle valve in accordance with a load, sensing a valve opening degree of the second throttle valve, judging whether or not the valve opening degree of the second throttle valve is an opening degree on a closing side relative to a predetermined set valve opening degree, and correcting the valve opening degree of the first throttle valve to the opening degree on the closing side relative to the target valve opening degree when it is judged that the valve opening degree of the second throttle valve is the opening degree on the closing side relative to the predetermined set valve opening degree.

A method of verifying a cylinder deactivation mode on an engine is provided. The method can include activating an ignition device in a deactivated cylinder during an exhaust stroke of the deactivated cylinder. The method can include measuring a voltage of the ignition device. The method can include comparing at least one of an amplitude and a timing of a measured spike of the voltage against a baseline voltage spike. The method can include indicating a status of the deactivation mode based on the comparison against the baseline voltage spike.

A method and system for determining remaining useful life of an in-use injector of a reciprocating engine is disclosed. The method includes determining nozzle wear relationship data for different duty cycles of the in-use injector, and using the nozzle wear relationship data together with operating parameters for the reciprocating engine, and emission relationship data to determine actual emission levels for the in-use injector based on the wear relationship data and the emission relationship data. The method and system further include determining remaining useful life of the in-use injector based on actual emission levels and the nozzle wear relationship data; and controlling an operation of the reciprocating engine based on the actual emission levels.

The subject matter of this specification can be embodied in, among other things, a method for characterizing a fluid injector that includes receiving a collection of waveform data, identifying a pull locus, determining a detection threshold level value, identifying a first subset of the collection of data representative of a selected first electrical waveform of the collection of electrical waveforms, identifying an opening value, identifying a representative closing value, identifying an anchor value, identifying a second subset of the collection of data based on the collection of data, the pull locus, the first subset, and the opening value, identifying a maximum electrical value, identifying an opening locus based the collection of data, the anchor value, and the maximum electrical value, identifying a hold value, and providing characteristics associated with the fluid injector comprising the pull locus, the opening locus, the hold value, the anchor value, and the representative closing value.