Bravo-
Brava
©
**
1999 update
Engine
Fuel system
10.
The pump is the volumetric type and is designed to run on unleaded
fuel.
The rotor is driven by a d.c.
electric motor receiving the battery voltage dirctly from the twin relay on the command of the control unit
in order to ensure that:
- the pump cuts out if the engine speed goes below a minimum level (about 450 rpm);
- the timed operation (around 15 seconds) each time the ignition key is turned to the ON position
with-
out the engine being started up;
- operation when the engine is strated up.
1.
Negative
2.
Fuel system
3. Supply
4.
Pre-filter
The pump is equipped with an excess pressure valve which short circuits the supply with the inlet if the
pressure in the supply circuit exceeds 5 bar to prevent the electric motor from overheating.
In addition, a one-way valve, fitted in the supply, prevents the entire fuel circuit from draining when the
pump is not working.
The pump nominal flow rate varies according to the speed of the rotor and therefore the supply voltage.
Fuel filter
The fuel filter is housed in the casing which surrounds the pump and does not require periodic replace-
ment.
Fuel pressure regulator
This is a differential diaphram device, regulated
at the factory to a pressure of 3.50±0.05 bar
and located in the top part of the drip tray.
The pressurized fuel (1), coming from the
pump,
exerts a force on the valve (3) opposed
by a calibrated spring (2). When the calibra-
tion pressure is exceeded, the valve opens and
the excess fuel (4) returns to the tank, thereby
stabilizing the pressure in the circuit.
Copyright Fiat Auto
37
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