Marea-Marea Weekend®^
Engine
1998
range
Fuel system
10.
Over-run
Two strategies are superimposed during this stage:
1. Transient negative strategy to reduce the amount of fuel required by the engine (lower emissions).
This stage is recognized by the ECU when the potentiometer signal changes from a higher voltage
level to a lower value.
2. A dash-pot strategy to lessen changes in torque delivery (lower engine brake).
This strategy is implemented when the potentiometer signal indicates that the throttle is closed and
rpm is high. The step motor gradually decreases the flow of air through the by-pass.
Barometric correction
Atmospheric pressure varies with altitude to bring about changes in volumetric efficiency of sufficient
entity to require a correction to baseline concentration (injection time).
Injection time is corrected according to changes in altitude and updated automatically by the ECU
whenever the engine is started up and under certain conditions of throttle position and rpm (dynamic
adjustment of barometric correction)
Cut-off
The fuel cut-off strategy is activated when the ECU recognises that the throttle is in closed position
(throttle potentiometer signal) and engine speed exceeds 1350 rpm (1750 rpm for automatic transmis-
sion versions). The ECU activates cut-off only when engine temperature exceeds 0° C.
The fuel supply is restored when the throttle is no longer closed or the engine speed is lower than 1270
rpm (1650 rpm for version with automatic transmission).
At very high speeds, cut-off takes place even when the throttle valve is not fully closed but pressure in
the intake manifold is particularly low (partial cut-off).
Version with manual
gearbox
1. 1350 rpm
2. 1270 rpm
Version with automatic
transmission
1. 1750 rpm
2. 1650 rpm
A. entering cut-off
B. leaving cut-off
Copyright Fiat Auto
1
Содержание 1998 Marea Weekend
Страница 10: ......
Страница 83: ......
Страница 90: ......
Страница 95: ......
Страница 133: ...f c...
Страница 290: ...Engine Fuel system 10 Hit TAG HI SYSTEM WIRING DIAGRAM Marea Marea Weekend 6 9 99 update I i 20 Wnf n 506 763 15...
Страница 298: ...Engine Fuel system Marea Marea Weekend ft 99 update 3N30GJ01 3N30GJ02 28 Print n 506 763 15...
Страница 342: ...Marea Marea Weekend 99 range Engine Fuel system Copyright by Fiat Auto 17...
Страница 391: ......
Страница 398: ...Engine Fuel system Marea Marea Weekend 99 range 6 Print n 506 763 14...
Страница 420: ......
Страница 452: ......
Страница 470: ...I...
Страница 499: ......
Страница 501: ......
Страница 508: ...Marea Marea Weekend Electrical equipment 98 range Key 55 4F36AN Copyright by Fiat Auto XII 98 Cancels and replaces 25...
Страница 580: ......
Страница 590: ...Electrical system Marea Marea Weekend Connector block 99 range 55 122 b Xfl 99 Update Publication n 506 763 19...
Страница 656: ......
Страница 723: ...Marea Marea Weekend Electrical equipment 99 range Wiring diagrams 55 Instrument panel connections Copyright Fiat Auto 57...
Страница 788: ......