In order to separately evaluate an influence degree of fuel and an influence degree of lubricating oil with respect to particulate matters contained in exhaust gas, an exhaust gas analysis method includes: analyzing particulate matters contained in the exhaust gas exhausted from an engine, thereby making it possible to analyze the particulate matters derived from the lubricating oil by using isooctane as a fuel.

A method and system of diagnosing a lubrication system of an engine includes determining a lubrication system fault and controlling an engine in response to the fault. The method is operative to first determine a poor state of health for a lubrication system, then determine an oil degradation or lube system fault. In response to a lube system fault, engine operation is altered in order to reduce the negative effects of the lube system fault such as increasing minimum idle speed in response to reduced oil pressure.

A system for controlling a variable turbocharger includes: a first controller outputting a duty value for adjusting an opening degree of a vane of a turbocharger, and a second controller checking opening or closing operations of the vane when the first controller adjusts the opening degree of the vane. In particular, the second controller outputs a corrected duty value by correcting the output duty value, based on a correction map, in consideration of a back pressure according to whether the vane is opened or closed.

Present embodiments provide a throttle body which may be used with a variety of engines of different manufacturers. The throttle body includes an inlet which expands to two or more bores, which extend downwardly through the throttle body. The throttle body may provide improved fuel pathways and fuel injector placement.

At least some implementations of a method of distinguishing between two loads being driven by an engine, includes the steps of determining engine speed at defined intervals, comparing a second engine speed against a previously determined first engine speed, determining if the second engine speed fits an expected pattern of engine speeds, and counting either the number of incidents where the second engine speed does not fit the expected pattern, or the number of incidents where the second engine speed does fit the expected pattern, or some combination of these two. A method of determining if an engine is operating at least near a lean limit of its air to fuel ratio is also disclosed.

A method and a device for controlling a combustion of an internal combustion engine are provided, including an arrangement, which generates a signal for the intensity of the combustion in a combustion chamber of the internal combustion engine from a sensor signal of the internal combustion engine. The intensity is compared to a reference level, which was formed from intensities of preceding combustions in the combustion chamber by moving average calculation. An irregular combustion is detected if the intensity exceeds the reference level in a predetermined manner, and then at least one operating parameter of the internal combustion engine is shifted in the direction of an avoidance of the irregular combustion. Following an irregular combustion, the averaging for forming the reference level is accelerated for a specified duration.

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.

At least some implementations of a method of distinguishing between two loads being driven by an engine, includes the steps of determining engine speed at defined intervals, comparing a second engine speed against a previously determined first engine speed, determining if the second engine speed fits an expected pattern of engine speeds, and counting either the number of incidents where the second engine speed does not fit the expected pattern, or the number of incidents where the second engine speed does fit the expected pattern, or some combination of these two. A method of determining if an engine is operating at least near a lean limit of its air to fuel ratio is also disclosed.

A method and system of diagnosing a lubrication system of an engine includes determining a lubrication system fault and controlling an engine in response to the fault. The method is operative to first determine a poor state of health for a lubrication system, then determine an oil degradation or lube system fault. In response to a lube system fault, engine operation is altered in order to reduce the negative effects of the lube system fault such as increasing minimum idle speed in response to reduced oil pressure.

An engine-driven working machine includes a controller, which varies a control value of a solenoid valve so as to decrease or increase an opening degree of the solenoid valve when a rotating speed of an engine is within a predetermined high rotating speed range and the rotating speed of the engine is lower or higher than a predetermined rotating speed, respectively. When the control value of the solenoid valve is varied so as to decrease the opening degree of the solenoid valve and corresponds to a predetermined opening degree larger than a fully-closed state, the control value is set to a limitation value.