Journal of KONES Powertrain and Transport, Vol. 22, No. 3 2015 INFLUENCE OF FUEL POLLUTANTS ON OPERATING PARAMETERS OF CONTEMPORARY FUEL INJECTOR Tomasz Osipowicz, Tomasz Stoeck, Wawrzyniec Gołębiewski West Pomeranian University of Technology Department of Automotive Engineering Piastów Avenue 19, 70-310 Szczecin, Poland tel.: +48 91 4494947 e-mail: tosipowicz@zut.edu.pl, tstoeck@zut.edu.pl, wgolebiewski@zut.edu.pl Abstract Article describes the operation issues of contemporary injection systems of Diesel engines. Common-rail system has been used since 1997, and since then there has been a significant evolution in its construction. In this aspect, there are changes in generations of high-pressure injection pumps and fuel injectors as well as methods of steering them, but exploitation problems are the same. The most prone to malfunction elements of the system are the fuel injectors. Their task is to distribute and to spray of the fuel in the combustion chamber of engine. Common Rail fuel injectors generate few injection dosages in the one work cycle. The rate of injection is depended on the design of the steering valve. One very important parameter of fuel injector is fuel injection delay time. If the time from control start of fuel injector to begin injection is shorter then it causes generation of greater number of injection dosages. Pollutants in fuel in the form of various amorphous solids of the size an even few microns cause the decrease of operating parameters of injector, which adversely affects the operation of the engine. Article shows contemporary fuel injectors, the methods of their examination, the types of fuel pollutants and their impact on fuel injector work. Keywords: fuel injector, Diesel engine, Common Rail injection systems 1. Introduction Diesel engine fuel injectors are responsible for distribution and spray the fuel to combustion chamber. In recent years, compression-ignition (CI) engines have attracted particular attention owing to their dynamic development [1, 3, 10]. In 1997, a Common Rail (CR) fuel injection system, which evolving all the time, was introduced due to the standards referring to exhaust gas toxicity. The main advantages of CR system are division of injected fuel dose by electronic control of fuel injector operation and possibility to reach high fuel injection pressure at present up to 250 MPa [2, 4, 9, 12]. The intention is that the rate of modern engine fuel supply system development meets the rigorous standards through such an organisation of the process of air-fuel mixture combustion so that as little toxic substances as possible are emitted to the air by the engine at the lowest possible fuel consumption, preserving its basic operating parameters, such as power and torque. The most dangerous for correct work of Diesel injectors is polluted fuel [5, 6, 7]. Following factors such as Diesel oil composition and content of refined substances and pollution penetrate during production, the percentage content of Biodiesel and transportation process has influence on fuel pollution. Deposits and contaminates are affected on dosages and discharges of Diesel fuel injectors [8, 11]. 2. Study objective The purpose of research was an analysis of influence of fuel pollutants on operating parameters of Common Rail fuel injectors. Experiments have been made according to following methodology: ISSN: 1231-4005 e-ISSN: 2354-0133 DOI: 10.5604/12314005.1166005