HEXA

ENGINE 80 f) High Pressure Pump (H.P. Pump) : HP pumps draws fuel from the fuel tank through the water Sedimentor and the fuel filter. It supplies high pressure fuel (up to 1600 bar) to the injectors. It has got inlet metering valve and in- built feed pump, integrated pressure limiter and integrated fuel temperature sensor. This pump is driven by the engine timing belt and controlled by EMS ECU based on the various operating parameters. Fuel Temperature Sensor ( FTS ) : This sensor monitors the temperature of fuel entering into the HP pump. It measures the fuel temperature on the pump hydraulic head in the low pressure circuit, between the transfer pump outlet and the inlet to the HP pumping stage. This sensor information is used to modify rail pressure control, injection etc. This sensor is in-built with HP Pump. Inlet Metering Valve ( IMV) : This controls fuel flow into pumping element in order to control rail pressure. This sensor is in- built with HP Pump. Venturi : It is an integral part of High pressure pump. It has inlet and outlet connections. One connection comes from injector back leak circuit & the other connection goes to the fuel tank ( return Line ), in between there is a "T" connector which goes to the fuel filter. g) Fuel Filler Cap : The fuel filler cap used EAGLE is a dual vented fuel filler cap. In addition to its function of providing an opening to fill fuel to the fuel tank it also helps in maintaining pressure in the fuel tank. It has a dual pressure valve that functions as follows: i. When the pressure in the fuel tank increases be- yond the specified limit of 10.5 KPa ~ 13.3 KPa it opens to release the vapour to the outside to relieve the pressure. ii. If a vacuum pressure of -6.0kPa is created in the tank, it opens up such that outside air is allowed in to bring back the pressure to safe limits. In addition a ratchet tightening device ensures that the filler cap is tightened to the correct torque. It also fitted with a O-ring that has to inspected regularly and replaced if it has hardened, broken or cracked.