HEXA

ENGINE

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.