Fiat Bravo Service Manual page 132

Engine Bravo-Brava iffii*,
Fuel system
10.
Injector
The injector performs the function of nebulizing the fuel necessary for forming the fuel mixture. It is
made out of stainless steel for more effective resistance to any impurities present in the fuel. It is con­
nected in a central position on the injector turret above the butterfly valve.
It consists of an outer case (1) containing coil (2) with a ferromagnetic core (3) and spring (4), which
performs the task of holding plunger (5) closed against the seat on bcase (6). The assembly is complet­
ed by other parts: electrical contacts (7), fuel intake channel (8) with filter (9), fuel outlet channel (10)
and filter (11).
Control pulses from the ECU reach the injector through electrical contacts (7) to set up a magnetic field
about core (3) through winding (2). Plunger (5) then lifts from its seat to overcome the load of counter-
spring (4) and bring about injector opening.
Plunger height is 0.06 mm (height x); If physical fuel properties are constant, the amount injected de­
pends solely on injector opening time (injection time), which is established by the ECU according to en­
gine service conditions.
The fuel jet leaves the injector at a pressure of about 1 bar, is immediately nebulized to form a cone of 30°
- 90° and injected upstream of the accelerator throttle. Injector control is synchronous, i.e. one injection
per ignition command.
A hole (12) on the accelerator throttle is designed to optimise mixture distribution within the intake
manifold while the engine is warming up.
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P4A30AJ01 P4A30AJ02
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Publication no. 506.670