In this study, the effects of fuel injection pressure changed from 45 to 65 MPa on combustion and emission characteristics were investigated in a common rail direct injection (CRDI) diesel engine fueled with diesel and palm oil biodiesel blends. The engine speed and engine load were controlled at constant 1700rpm and 100Nm, respectively. The tested fuel were PBD20 (20 vol.% palm oil biodiesel blended with 80 vol.% diesel fuel). The main and pilot injection timing was fixed at 3.5°CA BTDC and 27°CA BTDC (before top dead center), respectively. The experimental results show that the combustion pressure and heat release rate increased. In addition, the indicated mean effective pressure (IMEP) and maximum combustion pressure increased with an increase of the fuel injection pressure. Hydrocarbon (HC), smoke opacity and carbon monoxide (CO) decreased, but oxides of nitrogen (NOx) emissions increased as fuel injection pressure increased.

In this paper, we break away from the method of removing and inspecting the GDI injector, measure the pressure change of the fuel rail pressure sensor when driving the GDI injector of a vehicle equipped with the GDI fuel system, and compare the results. analyzed.There was a pressure change in the fuel rail pressure sensor from the general drive GDI injector. There was no pressure change in the fuel rail pressure sensor when driving the GDI injector without injecting fuel. You can check the fuel injection status in the pressure change data of the fuel rail pressure sensor without removal the GDI injector.