Fiat 1996 Brava Service Manual page 281

Engine
Fuel system
10.
1. accelerator control lever
2. idle speed adjustment actuator and but­
terfly position sensor
3. accelerator cable adjustment bracket
4. anti-tamper screw
Bravo-Brava igi lev
9 8 range
BUTTERFLY CASING
The butterfly casing has the task of metering
the quantity of air drawn in by the engine
(and consequently the power developed) ac­
cording to the driver's request via the acceler­
ator.
The butterfly casing is fixed to the inlet mani­
fold: the butterfly is opened by means of a
lever which has a gradual opeing law (small
butterfly opening angles for a good part of
the accelerator pedal travel and greater an­
gles in the last part of the travel.
With the pedal completely released (engine
decelerating or idling) the position of the
butterfly is regulated by the engine idle ad­
justment actuator in order to be able to sup­
ply the additional air required according to
the engine conditions. The actuator also in­
cludes the butterfly position sensor.
ENGINE IDLE SPEED ACTUATOR AAAND
BUTTERFLY POSITION SENSOR
The actuator, fitted on the butterfly casing,
consists of a direct current motor operated by
a circuit inside the engine control unit which
regulates the position of the butterfly: it has
the task of ensuring the additional air for the
engine with the accelerator pedal released,
under all circumstances when necessary
(idling, deceleration, external loads applied).
The maximum actuator opening angle is
around 30°.
The actuator contains a twin track poten­
tiometer:
- the first track goes from the closed position
to 30° and is used to control the butterfly
with the accelerator pedal released;
- the second track goes from the closed po­
sition to the maximum butterfly opening
position and is used for the normal engine
management.
Wiring connector
30
Print no. 506.670/16