Irregularity of rotational speed of diesel engine with modified fuel injection system

The operation of diesel engine is closely connected with controlling the process of injecting the fuel into the cylinder. It influences proper combustion process, which translates directly into irregular engine operation resulting in dumping and noise. It is related to improper control of fuel injection which is connected with improper completion of expected control strategy that can be a result of defective injection system. Irregular engine operation can also be caused by total lack of initiated combustion process in specific cylinder of the engine or in several cylinders, described as misfire, or ca be a result of differences in combustion process in individual operation cycles / engine cylinders. The effect is an engine working irregularly (there is instability of rotational speed) and emitting increased amount of pollutants. As a consequence the secondary fuel purification systems located in the exhaust system can be damaged. Therefore, it is required to choose the fuel injection control parameters in a way that enables detecting and correcting the process of fuel injection in order to minimize effects resulting from improper process of fuel combustion in individual cylinders or even lack thereof. It is useful to suggest diagnostic parameter that can be used to detect engine faultiness or elements of the accessories such as e.g. injection system. Ability to apply such control and correction of injection dose is provided by modified mechatronic in-line injection pump. The study shows results of researches on modified injection system with mechatronic in-line injection pump that enables identification of misfire and preventing irregular operation of diesel engine.