Various embodiments include a method for diagnosing a crankcase ventilation line of a crankcase ventilation device for an internal combustion engine having a crankcase, an intake tract, and a compressor arranged in the intake tract for compressing the intake air comprising: diverting fresh air from the intake tract via a fresh air supply line; either enabling or inhibiting a flow of fresh air into a free volume of the crankcase depending on a switch position of a shut-off valve in the fresh air supply line; detecting a nitrogen oxide concentration in the crankcase during the process of crankcase ventilation, close to the point of introduction into the intake tract upstream of the compressor using a nitrogen oxide sensor; and evaluating the tightness of the crankcase ventilation line based at least in part on the detected nitrogen oxide concentration.

Methods and systems are provided for identifying when an exhaust valve of an engine cylinder is not functioning as desired while the engine is being operated to raise a temperature of an exhaust system emissions control device, and in turn taking mitigating action. Thus, in one example a method comprises adjusting an amount of fuel that is provided to each of a plurality of cylinders of an engine during an exhaust stroke of the engine in response to an indication of degraded combustion stemming from a cylinder of the engine. In this way, the engine may continue to be operated to raise the temperature of the exhaust system emissions control device, while mitigating the issue of the degraded combustion.

Methods and systems are provided for identifying when an exhaust valve of an engine cylinder is not functioning as desired while the engine is being operated to raise a temperature of an exhaust system emissions control device, and in turn taking mitigating action. Thus, in one example a method comprises adjusting an amount of fuel that is provided to each of a plurality of cylinders of an engine during an exhaust stroke of the engine in response to an indication of degraded combustion stemming from a cylinder of the engine. In this way, the engine may continue to be operated to raise the temperature of the exhaust system emissions control device, while mitigating the issue of the degraded combustion.

The vehicle control device executes: a stop process for stopping fuel supply to two cylinders to be stopped; and a selection process of selecting one cylinder to be a stop instruction for stopping fuel supply from among the cylinders to be stopped. The selection process is a process of selecting a cylinder whose compression top dead center appears earliest among the stop target cylinders. The crank angle interval from when the cylinder to be the stop instruction target is selected until the stop instruction target cylinder is switched to the next cylinder among the stop target cylinders is the stoppable angle interval. The stop instruction for the selected cylinder is received before the fuel injection start time and at the stoppable angle interval. The control device executes a retard process of retarding the fuel injection start timing so that the stoppable angle interval includes the fuel injection start timing.

A method for implementation with the operation of an internal combustion engine, having an ignition plug, which is arranged on a combustion chamber of a cylinder of the internal combustion engine, wherein: in a first step, a cylinder pressure at the ignition time at the combustion chamber is detected, as well as a breakdown voltage at the ignition plug; and in a second step, a current electrode distance of the ignition electrodes, representing a current ignition electrode wear state, is determined based on the detected cylinder pressure, the detected breakdown voltage and a constant of proportionality.

An ignition performance increasing method of an automobile may include inputting a crank position sensor signal to detect a rotational position of a crankshaft of an engine, generating an engine angle tick, acquiring an engine synchronization by determining a position of the crankshaft and a position of a cam, setting a sync task at a specified position, and performing fuel injection and ignition.

In a sliding structure for an internal combustion, a cylinder has recesses in a stroke center region. Piston rings have inclined surfaces on an outer circumferential surface, and a lubricating oil flows between the inner wall surface and the outer circumferential surface that relatively move via the inclined surfaces. At any RPM equal to or greater than at idle, a center friction coefficient at the stroke center region through which the piston rings pass at the highest speed is less than a center friction coefficient when no recesses are formed in the stroke center region. Contrarily, at the RPM, an outside friction coefficient when the piston rings pass through a region outside the stroke center region is less than an outside friction coefficient when the recesses are formed in the outside region. As a result, further improved low fuel efficiency is achieved for the dimple liner technique.

Various embodiments include a method for diagnosing a crankcase ventilation line of a crankcase ventilation device for an internal combustion engine having a crankcase, an intake tract, and a compressor arranged in the intake tract for compressing the intake air comprising: diverting fresh air from the intake tract via a fresh air supply line; either enabling or inhibiting a flow of fresh air into a free volume of the crankcase depending on a switch position of a shut-off valve in the fresh air supply line; detecting a nitrogen oxide concentration in the crankcase during the process of crankcase ventilation, close to the point of introduction into the intake tract upstream of the compressor using a nitrogen oxide sensor; and evaluating the tightness of the crankcase ventilation line based at least in part on the detected nitrogen oxide concentration.

Methods and systems are provided for depressurizing a fuel tank of a vehicle by routing fuel tank vapors to an engine for combustion. In one example, a method may include reducing a pressure in the fuel tank by routing vapors from the fuel tank through a portion of a fuel vapor storage canister and, in response to an indication of a condition of degraded engine stability, re-routing the vapors from the fuel tank through an entirety of the fuel vapor storage canister. In this way, under conditions of degraded engine stability, a rate at which fuel tank vapors are directed to the engine may be reduced, which may thus mitigate the condition of degraded engine stability without aborting the operation to reduce the fuel tank pressure.

Methods and systems are provided for depressurizing a fuel tank of a vehicle by routing fuel tank vapors to an engine for combustion. In one example, a method may include reducing a pressure in the fuel tank by routing vapors from the fuel tank through a portion of a fuel vapor storage canister and, in response to an indication of a condition of degraded engine stability, re-routing the vapors from the fuel tank through an entirety of the fuel vapor storage canister. In this way, under conditions of degraded engine stability, a rate at which fuel tank vapors are directed to the engine may be reduced, which may thus mitigate the condition of degraded engine stability without aborting the operation to reduce the fuel tank pressure.