HEXA

ENGINE 79 Fuel System Priming Procedure : If the performance of the engine is affected due to the presence of the air in fuel system (commonly known as air lock), then detect can be removed by bleeding the fuel system. This can be done by pumping the priming pump by hand. Start engine and check for fuel leakage. Rectify if necessary. Check for smooth running of engine. Whenever replacing fuel sedimentor or filter, use priming pump to complete the fuel flow circuit. NOTE  Do not loosen the HP lines for bleeding the air from fuel system. Bleeding of the fuel system should be done only using priming pump. d) Common Rail : It is a fuel reservoir where the fuel is maintained at a pressure of about 1600 bar. The fuel is pumped into it from the HP pump and gets delivered to the injectors through the HP lines. It is also fitted with a rail pressure (RP) sensor and the signal is used by EMS ECU to maintain the fuel pressure. NOTE  Whenever fuel rail is removed from the engine, always cover the inlet and outlet openings of the rail with the protective caps. e) Injector : The injector used in VARICOR engine is a solenoid operated injector. This is controlled by the EMS ECU. The timing of injection and quantity is controlled by the EMS ECU. It operates at a pressure of 1600 bar. It makes multiple injections ( 2 pilot injections and 1 main injection) with short intervals between each injection. The injector has a unique 20 digit hexadecimal I3C code by which the EMS ECU recognizes it. Whenever an injector is replaced, it should be re- calibrated using the Diagnostic tool by entering the I3C code. For procedure refer EMS ECU Diagnostic software users’ manual in this group. NOTE  Injectors should not to be interchanged in during service since individual injector characterization is different and I3C no. of each injector is written in the ECU during engine assembly.