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Problems of reducing emissions of harmful substances and fuel consumption of the engine are interrelated, since they are mainly determined by the work process. Measures aimed to reducing fuel consumption cause changes, often upwards, toxic compound formation. The fuel and environmental criterion is proposed taking into account the engine operating conditions for a reasonable choice of technical solutions for the comprehensive improvement of fuel economy and toxic level indicators of the exhaust gases. This criterion allows assessing the effectiveness of solutions to improve combustion efficiency, the use of alternative fuels, exhaust gas aftertreatment systems, and other measures.

In connection with the tightening of environmental standards, the leading manufacturers of marine low-speed engines are carrying out intensive work on their conversion to gas fuels. Due to the design features in this class of engines, only internal mixture formation is possible. For the organization of which two different approaches are possible. To date, only two are currently implemented. MAN started production of engines with gas fuel supply to the working cylinder under high pressure at the end of the compression stroke, and WinGD under low pressure at the beginning of the compression stroke. The analysis, performed by the authors, showed, that increasing the pressure before the gas supplying mechanisms to 3.5...6.0 MPa can reduce the residence time of the gas-air mixture in the working cylinder and reduce the likelihood of detonation combustion.

The article discusses the use of the combined heating system with phase-transitional thermal accumulator. The peculiarity of the presented system is that it uses thermal energy of exhaust gas, coolant and motor oil, and emissions of the internal combustion engine during its operation to accumulate the thermal energy. The results of experimental studies of the combined heating system are shown. A system and methods for pre-start and after-start heating of the vehicular engine in the investigated system are developed. The structure of the "combined heating” system to study the impact of its structural and adjustment parameters on the performance of thermal development of the vehicular engine is described. The use of the combined heating system within phase-transitional thermal accumulators is compared with the use of standard systems for a truck engine 8FS 9.2 / 8. It reduces the time of coolant and motor oil thermal development by 22.9-57.5% and 25-57% accordingly.

The article deals with experimental and theoretical researches of hydraulic processes in a system of accumulator fuel supplying (Common Rail) during the diagnosing while the vehicle idling and during the acceleration. The aim of the work is to assess the efficiency of the offered diagnosing technique as the point of view of cutting-down time for troubleshooting and as the point of view of increasing reliability of failure localization. Feature of the presented approach is that it uses the analysis of fuel pressure fluctuations in the high pressure hydroaccumulator, synchronously with the analysis of rotary speed of an engine crankshaft and the steering signals on electromagnetic magnets (or piezoelements) of injectors. The technique uniting preliminary diagnosing of Electronic Engine Control (EEC) and components of the vehicle fuel units during the constant remote monitoring process, and deep, detailed diagnosing at a service station is described.