Experimental Study on the Match between Electronic Unit Pump and Diesel Engine

An injection system of Delphi Electronic Unit Pump (EUP) matched speed-down cam profile was employed to study on the effect of EUP pre-lift on the match between EUP and diesel engine. It can be found that the EUP pre-lift has direct effect on the match between EUP and diesel engine as the prelift determines the effective operation range of the constant pressure segment (CPS) of EUP. When the EUP works in the CPS, the two items of the maximum injection pressure (MIP) and the fuel delivery per cycle (FDPC) keep the same. If not, both of them decrease significantly. In addition, it is found the pre-lift of 11.5mm is more suitable of the match between the EUP and a V-type eight-cylinder turbocharged diesel engine according to its variation laws of the specific fuel consumption (SFC) and the maximum combustion pressure (MCP) with the injection advance angle (IAA).