This failure determining device is provided with a first determining unit which refers to correction amount data indicating a correction amount relating to operation of a part related to an internal combustion engine, to determine whether there is a possibility that the internal combustion engine has failed, a data acquiring unit which, if it has been determined that there is a possibility that the internal combustion engine has failed, acquires influencing factor data indicating a factor influencing the correction amount, and a second determining unit which refers to the correction amount data together with the acquired influencing factor data to determine whether the internal combustion engine has failed.

An engine torque estimating apparatus having a processor and a memory accessed by the processor. The processor performs a torque estimating that calculates time series data of an estimated indicated torque, based on a crank angle having been extracted from an output of a crank angle sensor of an engine including a plurality of cylinders; an estimated indicated torque-related value extracting that extracts an estimated indicated torque-related value, for each of the cylinders, from the time series data of the estimated indicated torque, for each of the cylinders; and average indicated torque correct value acquiring that converts, for each of the cylinders, the estimated indicated torque-related value into an average indicated torque correct value having been calculated based on a cylinder internal state of the engine in correspondence to the estimated indicated torque-related value.

Methods and systems are provided for controlling imbalance with an exhaust tuning valve. In one example, a method may include adjusting a first exhaust tuning valve in response to combustion torque imbalance in a first and second group of cylinders. Additionally or alternatively, the position of the second exhaust tuning valve may be adjusted in response to an imbalance generated by the same group of cylinders.

A method for operating an internal combustion engine, including aligning an injection behavior of the number of injectors. Aligning the injection behavior includes switching off one injector of the number of injectors, detecting a signal of the internal combustion engine that is to be assigned to the switched off injector, determining an alignment characteristic from the signal and assigning the alignment characteristic to the switched off injector as an alignment characteristic assigned to the injector, and switching on the previously switched off injector. Aligning the injection behavior further includes performing the aforementioned steps sequentially for the other injectors of the number of injectors and correcting a control of an injector that is to be corrected using the measured value assigned to the injector that is to be corrected.

Methods and systems are provided for balancing a plurality of fuel injectors via a diagnostic. In one example, a method may include adjusting a fuel injection pattern to increase an occurrence of a fuel injection being preceded by a same-cylinder bank fuel injection. The method may further include skipping fuel injections resulting in the fuel injection being preceded by an opposite-cylinder bank fuel injection.

Methods and systems are provided for increasing a temperature of a catalyst of an engine by operating the engine in a split lambda catalyst heating mode. In one example, a method may include, while operating an engine in a split lambda catalyst heating mode, adjusting a magnitude of a lambda split between a rich set of combustion events and a lean set of combustion events based on soot formation in the rich set of combustion events. In this way, catalyst temperature may be increased while maintaining engine efficiency and preventing soot formation in the cylinders.

A misfire detection device for an internal combustion engine is configured to execute: a deactivating process that deactivates combustion control for air-fuel mixture in one or some of cylinders; a provisional determination process that uses a detection value of a sensor to output a logical value indicating whether a misfire has occurred; a provisional determination counting process that counts a number of times a specific one of the logical value output by the provisional determination counting process has been output; and an official determination process that makes an official determination of whether the misfire has occurred using, as an input, the number of times counted by the provisional determination counting process during a specific period.

A controller for an internal combustion engine, a control method for an internal combustion engine, and a memory medium are provided. The controller determines whether an execution request of a temperature-increasing process for an aftertreatment device for exhaust gas has been issued. When the execution request is determined as having been issued, supply of fuel by a fuel injection valve corresponding to a specified cylinder is deactivated. The specified cylinder is one of cylinders. An air-fuel ratio of air-fuel mixture in a cylinder of the cylinders that differs from the specified cylinder is set to be richer than a stoichiometric air-fuel ratio. When the temperature-increasing process is executed, an adjustment device is operated so as to reduce the fuel concentration in an intake port connected to the specified cylinder.

A system and method for operating an ICE by (a) generating a running history of one or more-cylinder events per cylinder, and (b) using the running history to select a least-used non-rotating firing pattern, among a plurality of non-rotating firing patterns, provided for each firing fraction less than one (1). By making the least used selection based on the running history, unequal usage among cylinders of the ICE can be mitigated.

A method of adjusting operation of an internal combustion engine includes injecting fuel into cylinders of the internal combustion engine (first fuel operation); obtaining a first fuel exhaust temperature profile during the first fuel operation; injecting two fuels into the cylinders in a duel fuel operation; obtaining a duel fuel exhaust temperature profile; and adjusting the injection quantity and/or an injection timing of one fuel in a cylinder(s), based on a difference between the first fuel exhaust temperature profile and the duel fuel exhaust temperature profile. Other methods of operating with single fuel and using sensors other than exhaust temperature sensors are disclosed.