Engine
Fuel system
Marea-Marea Weekend
01
1998 range
10.
Acceleration
During this stage, the ECU increases the amount of fuel required by the engine (to achieve maximum
torque) on the basis of signals from the following sensors:
- throttle potentiometer;
- absolute pressure sensor;
- rpm and TDC sensor.
The base pulse constant is multiplied by a factor according to coolant temperature and accelerator throt-
tle opening speed.
If an abrupt change in injection time is calculated when the injector is already closed, the ECU reopens
the injector (extra pulse), in order to make the concentration up to the required level as quickly as possi-
ble. Subsequent injections are automatically increased as described previously.
A. normal injection time
B. injector re-opening
(extra pulse)
C. injection time including
enrichment
OFF. engine under steady-s-
tate conditions
ON. engine under transient
conditions
Protection against excess rpm
When engine rpm exceeds a level of 6700 rpm for longer than 10 seconds or an upper threshold of 6900
rpm imposed by the manufacturer for any length of time, engine operating conditions are said to be criti-
cal.
When the ECU recognises that this threshold rpm level has been exceeded, it reduces injector control
time.
When rpm drops to non-critical levels, control is restored.
Electric fuel pump drive
The fuel pump is governed by the ECU through a relay.
The pump stops when:
- engine speed drops below 50 rpm;
- after a certain time (5 seconds) with the ignition turned to MAR without
start-up taking place (timed enablement).
- if the inertia switch is activated.
Injector control
Injectors are controlled in sequential, phased manner. During start-up, however, all injectors are initially
all controlled in parallel (full-group).
Injector control timing varies according to engine speed and intake air pressure in order to improve
cylinder filling because this makes for better fuel economy, good handling and lower emission levels.
8
Publication no. 506.763/09
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: ......