A misfire detection device for an internal combustion engine is provided. A mapping takes time series data of instantaneous speed parameters as inputs. Each instantaneous speed parameter corresponds to one of a plurality of successive second intervals in a first interval. The instantaneous speed parameters correspond to the rotational speed of the crankshaft. The first interval is a rotational angular interval of the crankshaft in which compression top dead center occurs. The second interval is smaller than an interval between compression top dead center positions. The mapping outputs a probability that a misfire has occurred in at least one cylinder that reaches compression top dead center in the first interval. The mapping data defining the mapping has been learned by machine learning.

A system includes one or more processors that are configured to obtain a measured fuel consumption rate for an internal combustion engine while the engine is operating at a predetermined operating condition to perform a mission. The one or more processors are also configured to compare the measured fuel consumption rate with an expected fuel consumption rate for the predetermined operating condition. Further, the one or more processors are configured to determine whether an injector flow limiter is in a latched condition based on the measured fuel consumption rate compared with the expected fuel consumption rate. Also, the one or more processors are configured to perform a responsive action responsive to determining that the injector flow limiter is in the latched condition.

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.

An engine start control device is provided with: a starter relay that is provided between a battery and a starter motor; a start abnormality determining means that determines the occurrence of start abnormality of an engine; and a start control means, which turns on the starter relay, and starts supplying power from the battery to the starter motor in the cases where a start instruction signal is inputted from a start switch, and which turns off the starter relay in the cases where the start abnormality determining means determined the occurrence of start abnormality of the engine.

A diagnosis apparatus of a fuel supply system includes an operation state detector, an air-fuel ratio sensor, a fuel injection amount calculator, a threshold value table, an abnormality information acquiring device, and an abnormality determining device. In the threshold value table, operation ranges of an internal combustion engine are provided based on an engine speed and a throttle opening. In the threshold value table, a lean side threshold value and a rich side threshold value of an air-fuel ratio correction factor to determine abnormality of the fuel supply system are set beforehand for each of the operation ranges. The abnormality information acquiring device is configured to determine whether the air-fuel ratio correction factor has exceeded the lean side threshold value or the rich side threshold value extracted from the threshold value table according to an operation state so as to acquire abnormality information.

A system includes an electronic fuel injection system of an engine, the electronic fuel injection system including an electronic governor control unit for controlling various functions of the engine.

An abnormality diagnosis system is applied to a fuel supply system including a fuel pump that pumps fuel from a fuel tank and a fuel pipe in which fuel discharged from the fuel pump flows. The abnormality diagnosis system stores a minimum fuel pressure in the fuel pipe in one trip after a main switch of the fuel supply system is turned on and until the main switch is turned off and data indicating a state when the minimum fuel pressure was recorded as diagnosis data in a storage device. In the abnormality diagnosis system, an execution device determines a failure spot associated with a decrease in fuel pressure in the fuel pipe using the diagnosis data stored in the storage device and diagnoses an abnormality of the fuel supply system.

The occurrence of the misfire having a level at which exhaust purifying function of a catalyst is impaired (OT-level misfire) is detected. Upon the detection of the OT-level misfire, basic OT risk from the misfire is multiplied by a correction coefficient corresponding to the accumulated PM amount on the catalyst. The basic OT risk from the misfire is a basic value of OT risk from the misfire which is set based on the operating condition of the engine. The correction coefficient is set to a smaller value as the accumulated PM amount increases. Therefore, the OT risk from the misfire after the multiplication decreases as the accumulated PM amount increases. When a predetermined judgement condition with the OT risk from the misfire is established, it is judged that the misfire having the level occurs.

A method for automatically starting and stopping engine(s) of a vessel based on the position of a handle. Automatic starting occurs by activating an ignition circuit, receiving a signal indicating handle position, and providing a signal to start the engine when the handle is out of neutral position. A signal to shift the transmission into gear is sent when the handle is in an idle position. Automatic stopping of the engine includes receiving a signal the handle is in neutral, receiving status information of the engine, and providing a signal to stop the engine when the handle is in neutral and either the engine is not running or at least one of a number of conditions are met. A shutoff timer may delay auto stop of the engine, which may reset whenever any of the conditions ceases to be true.

A method and an apparatus including a processing circuit structured to: receive a first signal indicative of an upstream air-fuel equivalence ratio from a first sensor positioned upstream of an intake of a catalyst, the first signal defining a duty cycle, receive a second signal indicative of a downstream air-fuel equivalence ratio from a second sensor positioned downstream of the intake of the catalyst, adjust the duty cycle based at least in part on the second signal, and provide a fault signal in response to the duty cycle not meeting a duty cycle range for a predetermined period of time. A notification circuit is structured to provide a notification indicating that the second sensor is faulty in response to receiving the fault signal.