Fiat 1996 Brava Service Manual page 257

Bravo-Brava ig| 16v
98 range
Engine
Fuel system
10.
In particular/the signal is composed as follows.
There are sixty teeth on the flywheel, two of which have been removed to create discontinuity: the angle
between the two consecutive teeth is therefore 6°:
The synchronism point is recognized at the end of the first tooth following the two missing teeth: the fly­
wheel is fitted so that as the engine passes this tooth cylinders 1 and 4 are 17 teeth before TDC.
1. Engine rpm and TDC sensor
2. Gap
3. Flywheel 60-2 teeth
4. Signal corresponding to two missing teeth
5. Flywheel signal (engine speed sensor)
MANAGEMENT OF THE INJECTION
The injection management strategies are designed to provide the engine with the. correct quantity of fuel
at the desired moment according to the engine operating conditions.
The management of the injection basically consists of calculating the injection time, determining the in­
jection phase and then the implementation by operating the injector.
The "basic" injection time is calculated by means of mathematical interpolation of the speed-load map:
the figures contained in the map, which have been obtained experimentally, also depend on the charac­
teristics of the injector.
The "final" injection time "is determined by means of a calculation algorhythm in which the "basic" in­
jection time is corrected by a series of coefficients which take into account the different engine operat­
ing conditions which are highlighted by the various system sensors.
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