Fiat 1998 Marea Weekend, Service Manual

Page: 244 / 846

Engine
Fuel system
Marea- Marea Weekend 0
99 range
10.
1. accelerator control lever
2. idle speed adjustment actuator and butter-
fly position sensor
3. accelerator cable adjustment bracket
4 . anti-tamper screw
BUTTERFLY CASING
The butterfly casing has the task of metering
the quantity of air drawn in by the engine (and
therefore the power developed) according to
the driver's request via the accelerator.
The butterfly casing is fixed to the inlet mani-
fold: the butterfly is opened via a lever through
a gradual opening law (small butterfly opening
angles for a large part of the accelerator pedal
stroke and large angles in the last part of the
stroke).
With the pedal completely released (engine
decelerating or idling) the position of the but-
terfly is regulated by the engine idle adjust-
ment actuator in order to be able to supply the
additional air required according to the engine
conditions. The actuator also includes the
butterfly position sensor.
4F030PJ03
ENGINE IDLE SPEED ADJUSTMENT A C -
TUATOR AND 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, in
all conditions where this is necessary (idling,
deceleration, external loads applied).
The maximum angular opening which can be
achieved by the actuator is around 30°.
- the first track goes from the closed position
up to 30° and is used for the operation of the
butterfly with the accelerator pedal released;
- the second track goes from the closed posi-
tion up to the maximum butterfly opening
and is
?
used for the normal management of
the engine.
Connector wiring
30
Print n'506.763/14