Fiat 1996 Brava Service Manual page 384

Bravo-Brava ty
TD100
Engine
Fuel system
10.
INJECTION PUMP
The Lucas FT09 injection pump has been specifically designed for indirect injection diesel engines with
special innovative features which ensure optimum engine running in all operating conditions; in partic­
ular, it allows a decrease in consumption, harmful emissions and noise levels.
The function of the injection pump is to accurately meter the quantity of fuel and to inject it at high pres­
sure into the combustion chamber for each cylinder at a precise moment in the engine cycle; the quantity
of fuel metered is therefore atomized at high pressure by the injector.
It is vital for the injection pump to be working accurately and reliably because the cycle is repeated thou­
sands of times per minute; therefore variations in the injection point (advance) or the quantity of fuel in­
jected (metering) are not permissible for the entire life of the engine.
The injection pump is characterized by being rather small in size; it is the rotary distributor type, compact
in structure and does not require any external lubrication because it is lubricated by the filtered diesel fu­
el with which it is always filled during operation.
The internal pressure prevents penetration of dust, water or other foreign bodies which would be harm­
ful to its operation; in addition the special design of the hydraulic circuits prevent the accumulation of
air.
To facilitate both starting and the supply of full power, irrespective of the climate conditions, the pump is
equipped with an automatic flow rate supplement system which increases the amount of fuel injected.
The pump comprises a single pumping element, made up of two opposing pistons, which is an integral
part of the distribution rotor. The rotor, in turn, rotates inside a unit known as the hydraulic head.
Each piston comes into contact with the internal lobes of a cam seal by means of an assembly made up
of a roller and a roller carrier plate.
The adoption of a single pumping element ensures a uniform supply of fuel for each cylinder and dis­
penses with balancing the supplies, an operation which is otherwise strictly necessary in all pumps fitted
with separate pumping elements.
The fuel, carefully metered during the intake stage into the pumping element, is distributed to each in­
jector at the exact moment thanks to a system of ports in the hydraulic head and the rotor.
When it receives the command from the electronic control unit, the pump can alter the injection advance
and is therefore capable of adjusting the start of the injection in the engine cycle so that it takes place at
the optimum time in all operating conditions.
The pump is also equipped with
a mechanical centrifugal regula­
tor to accurately check the en­
gine speed.
1.
2.
4.
5.
6.
7.
8.
9.
10.
Idle speed adjustment screw
Connector for diesel return
pipe to the tank
Accelerator control lever
position sensor
Accelerator control lever
Electro-stop valve anti--
tamper cover
Fast idle device
Connector for diesel supply
pipe from the filter
Connector for diesel supply
pipe to the injectors
Advance actuator
Fast idle control cable
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IX-96 - Cancels and replaces
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