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Ford Fiesta (1989-1995). Instruction - part 32

1595Ford Fiesta Remake

General

System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electronic Fuel injection (EFi) with turbocharger on RS Turbo models

Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.6 litre CVH engines

Fuel grade

Fuel octane requirement:

Engines without catalytic converter* . . . . . . . . . . . . . . . . . . . . . . . . . .

95 RON unleaded or 97 RON leaded

Engines with catalytic converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

95 RON unleaded (leaded fuel must not be used)

*Refer to dealer for latest recommendations

Fuel system data

Idle speed and mixture settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

See Chapter 1

Fuel pump pressure - engine not running . . . . . . . . . . . . . . . . . . . . . . .

3.0 bars minimum

Regulated fuel pressure - engine running at idle speed . . . . . . . . . . . . .

2.3 to 2.5 bars

Hold pressure - engine stopped after two minutes . . . . . . . . . . . . . . . .

Not less than 0.8 bars below regulated pressure

Turbocharger

Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Garrett AiResearch T02

Boost pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.47 to 0.51 bars

Chapter 4 Part C:
Fuel system - electronic fuel injection engines

Accelerator cable - removal, refitting and adjustment . . . . . . . . . . .

Accelerator pedal - removal and refitting . . . . . . . . . . . . . . . . . . . . .

Air cleaner assembly and air inlet components - removal and

refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Air cleaner element renewal  . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Fuel cut-off switch - removal and refitting  . . . . . . . . . . . . . . . . . . . . 12
Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Fuel injection system - checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Fuel injection system components - removal and refitting  . . . . . . . . 14
Fuel lines and fittings - general information  . . . . . . . . . . . . . . . . . . .

Fuel pump/fuel gauge sender unit - removal and refitting . . . . . . . .

Fuel pump/fuel pressure - checking . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel system - depressurisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel tank - removal, inspection and refitting . . . . . . . . . . . . . . . . . . .

Fuel tank filler pipe - removal and refitting  . . . . . . . . . . . . . . . . . . . . 11
Fuel tank ventilation tube - removal and refitting  . . . . . . . . . . . . . . . 10
General fuel system checks  . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
General information and precautions  . . . . . . . . . . . . . . . . . . . . . . . .

Idle speed and mixture check and adjustment  . . . . . . . .See Chapter 1
Idle speed control valve cleaning and maintenance  . . . .See Chapter 1
Inlet manifold - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . 15
Intercooler - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Turbocharger - general information and precautions  . . . . . . . . . . . . 16
Turbocharger - removal, examination and refitting  . . . . . . . . . . . . . . 20
Turbocharger boost control valve - removal and refitting . . . . . . . . . 18
Turbocharger boost pressure - checking and adjustment  . . . . . . . . 19
Underbody fuel/brake line check . . . . . . . . . . . . . . . . . . .See Chapter 1
Underbonnet check for fluid leaks and hose condition . .See Chapter 1

4C•1

Specifications

Contents

Easy, suitable for
novice with little
experience

Fairly easy, suitable
for beginner with
some experience

Fairly difficult,
suitable for competent
DIY mechanic

Difficult, suitable for
experienced DIY
mechanic

Very difficult,
suitable for expert DIY
or professional

Degrees of difficulty

Torque wrench settings

lbf ft

Idle speed control valve bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 to 5

3 to 4

Fuel pressure regulator bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8 to 12

6 to 9

Fuel rail bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20 to 26

15 to 19

Inlet air temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20 to 25

15 to 18

Inlet manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16 to 20

12 to 15

Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

50 to 70

37 to 52

Intercooler-to-radiator bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 to 6

3 to 5

Boost control valve screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.2 to 2.7

1.5 to 2

Exhaust manifold heatshield bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21 to 26

16 to 19

Exhaust manifold-to-engine nuts (non-Turbo models) . . . . . . . . . . . . . .

14 to 17

11 to 13

Exhaust manifold-to-engine nuts (Turbo models) . . . . . . . . . . . . . . . . .

28 to 31

21 to 23

Exhaust manifold-to-turbocharger bolts . . . . . . . . . . . . . . . . . . . . . . . .

20 to 28

15 to 21

Turbocharger-to-exhaust downpipe nuts . . . . . . . . . . . . . . . . . . . . . . . .

35 to 47

26 to 35

Turbocharger cooling pipe banjo union bolts . . . . . . . . . . . . . . . . . . . . .

22 to 29

17 to 22

Turbocharger oil feed and return line couplings . . . . . . . . . . . . . . . . . . .

15 to 20

11 to 15

4C•2 Fuel system - electronic fuel injection engines

1595Ford Fiesta Remake

General information and
precautions

General information

The fuel system consists of a fuel tank

(mounted under the body, beneath the rear
seats), fuel hoses, an electric fuel pump
mounted in the fuel tank, and an electronic
fuel injection system.

Fuel is supplied under pressure from the

fuel pump to the fuel distributor rail mounted
on top of the inlet manifold (see illustration).
The fuel rail acts as a pressurised fuel
reservoir for the fuel injectors. The electro-
mechanical injectors have only “on” or “off”
positions, the volume of fuel being injected to

meet the engine operating conditions being
determined by the length of time that the
injectors are opened. The volume of fuel
required for one power stroke is determined
by the EEC IV engine management module,
and is divided by two equal amounts. The first
half of the required volume is injected into the
static air ahead of the inlet valve one complete
engine revolution before the inlet valve is due
to open. After one further revolution, the inlet
valve opens and the required fuel volume is
injected into the air flow being drawn into the
cylinder. The fuel will therefore be consistently
injected to two inlet valves simultaneously at a
particular crankshaft position.

The volume of air drawn into the engine is

governed by the air filter unit and other
variable operating factors. These variables are
assessed by the EEC IV module and the

corresponding signals are produced to
actuate the injectors accordingly.

The engine base idle speed can be

adjusted (if required), by turning the adjuster
screw (covered by a tamperproof cap) in the
throttle housing. Provision for adjusting the
fuel mixture is made by the mixture screw in
the potentiometer unit mounted on the
bulkhead.

An idle speed control valve, itself controlled

by the EEC-IV engine management module,
stabilises the engine idle speed under all
conditions by the opening of an auxiliary air
passage which bypasses the throttle. Apart
from a base-idle speed adjustment, no
adjustments to the operational idle speed can
be made.

The EEC IV module is the heart of the entire

engine management system, controlling the
fuel injection, ignition and emissions control
systems. The module receives information
from various sensors to determine engine
temperature, speed and load, and the
quantity of air entering the engine. The
sensors also inform the module of throttle
position, inlet air temperature and, on models
with catalytic converters, exhaust gas oxygen
content. All the information supplied to the
module is computed and compared with
pre-set values stored in it’s memory, to
determine the required period of injection.

Information on crankshaft position and

engine speed is generated by a crankshaft
position sensor. The inductive head of the
sensor runs just above the engine flywheel
and scans a series of 36 protrusions on the
flywheel periphery. As the crankshaft
rotates, the sensor transmits a pulse to the
system’s ignition module every time a
protrusion passes it. There is one missing
protrusion in the flywheel periphery at a point
corresponding to 90° BTDC. The ignition
module recognises the absence of a pulse
from the crankshaft position sensor at this
point to establish a reference mark for
crankshaft position. Similarly, the time interval
between absent pulses is used to determine
engine speed. This information is then fed to
the EEC IV module for further processing.

1.2 General view of the 1.6 litre EFi fuel injection system arrangement

1 Throttle housing
2 Upper inlet manifold section
3 Wiring loom connector
4 Intake air temperature

sensor

5 Wiring harness ducting
6 Fuel rail
7 Lower section of inlet

manifold

8 Cylinder head

9 Fuel injector
10 Fuel pressure regulator
11 Vacuum hose
12 Air inlet duct

Engine temperature information is supplied

by the coolant temperature sensor. This
component is an NTC (Negative Temperature
Coefficient) thermistor - that is, a semi-
conductor whose electrical resistance
decreases as its temperature increases. It
provides the EEC IV module with a constantly-
varying (analogue) voltage signal, corre-
sponding to the temperature of the engine
coolant. This is used to refine the calculations
made by the module, when determining the
correct amount of fuel required to achieve the
ideal air/fuel mixture ratio.

Inlet air temperature information is supplied

by the inlet air temperature sensor. This
component is also an NTC thermistor - see the
previous paragraph - providing the module with
a signal corresponding to the temperature of air
passing into the engine. This is used to refine
the calculations made by the module, when
determining the correct amount of fuel required
to achieve the ideal air/fuel mixture ratio.

A throttle position sensor is mounted on the

end of the throttle valve spindle, to provide
the EEC IV module with a constantly-varying
(analogue) voltage signal corresponding to the
throttle opening. This allows the module to
register the driver’s input when determining
the amount of fuel required by the engine.

Road speed is monitored by the vehicle

speed sensor. This component is a Hall-effect
generator, mounted on the transmission’s
speedometer drive. It supplies the module with a
series of pulses corresponding to the vehicle’s
road speed, enabling the module to control
features such as the fuel shut-off on overrun.

A manifold absolute pressure sensor

measures inlet manifold vacuum, and supplies
this information to the EEC IV module for
calculation of engine load at any given throttle
position.

Where power steering is fitted, a pressure-

operated switch is screwed into the power
steering system’s high-pressure pipe. The
switch sends a signal to the EEC IV module to
reduce engine speed should the power steering
fluid pressure become excessively high.

On models with a catalytic converter, the

oxygen sensor in the exhaust system provides
the EEC IV module with constant feedback -
“closed-loop” control - which enables it to
adjust the mixture to provide the best possible
conditions for the catalytic converter to operate.

On turbocharged engines, control of the

turbocharger boost pressure is also governed
by the EEC IV module, acting through the
boost control valve. This allows inlet manifold
depression to be applied to the turbocharger
wastegate control.

The turbocharger consists of a turbine that

is driven by the exhaust gases, to suck air
through the air filter and to compress it into the
engine. An air-cooled intercooler, mounted
next to the radiator, cools the inlet air (heated
by its passage through the turbocharger); this
increases the density of the compressed
fuel/air mixture entering the engine, thus
improving the engine’s power output.

Precautions

Warning: Petrol is extremely
flammable - great care must be
taken when working on any part
of the fuel system. Do not

smoke or allow any naked flames or
uncovered light bulbs near the work area.
Note that gas powered domestic
appliances with pilot flames, such as
heaters, boilers and tumble dryers, also
present a fire hazard - bear this in mind if
you are working in an area where such
appliances are present. Always keep a
suitable fire extinguisher close to the work
area and familiarise yourself with its
operation before starting work. Wear eye
protection when working on fuel systems
and wash off any fuel spilt on bare skin
immediately with soap and water. Note
that fuel vapour is just as dangerous as
liquid fuel; a vessel that has just been
emptied of liquid fuel will still contain
vapour and can be potentially explosive.
Petrol is a highly dangerous and volatile
liquid, and the precautions necessary
when handling it cannot be overstressed.

Many of the operations described in this

Chapter involve the disconnection of fuel
lines, which may cause an amount of fuel
spillage. Before commencing work, refer
to the above Warning and the information
in “Safety first” at the beginning of this
instruction.

When working with fuel system

components, pay particular attention to
cleanliness - dirt entering the fuel system
may cause blockages which will lead to
poor running.
Note: Residual pressure will remain in the fuel
lines long after the vehicle was last used,
when disconnecting any fuel line, it will be
necessary to depressurise the fuel system as
described in Section 2.
Note: Refer to Section 16 for specific
precautions relating to turbocharged engines.

Fuel system -
depressurisation

Refer to Part B, Section 2.

Fuel lines and fittings -
general information

Refer to Part B, Section 3.

Air cleaner assembly and air
inlet components - removal
and refitting

Note: Air cleaner element renewal and air
cleaner temperature control system checks
(where applicable) are described in Chapter 1.

Air cleaner assembly

1 Disconnect the battery negative (earth) lead
(refer to Chapter 5A, Section 1).
2 If the idle speed control valve is mounted
on the air cleaner, disconnect the multi-plug
and the air bypass hose from the valve.
3 Disconnect the flexible hose between the
air cleaner lid and the air inlet duct or
turbocharger air inlet.
4 Disconnect the crankcase breather hose
from the front of the air cleaner housing.
5 Unclip and remove the air cleaner lid, then
withdraw the element.
6 Remove the two bolts securing the forward
end of the air cleaner housing, free the
rearward end of the housing from its location
and carefully withdraw from the vehicle (see
illustration).
7 Refitting is a reversal of the removal
procedure.

Air inlet components

8 Disconnect the battery negative (earth) lead
(refer to Chapter 5A, Section 1).
9 If the idle speed control valve is mounted
on the air cleaner, disconnect the multi-plug
and the air bypass hose from the valve (see
illustration).
10 Disconnect the HT leads from the spark
plugs, labelling them if necessary to avoid
confusion on refitting.

Fuel system - electronic fuel injection engines 4C•3

4.9 General view of the air inlet

components on non-Turbo models

A Air inlet duct
B Air inlet duct securing bolts
C Spark plug HT lead connectors
D Air cleaner lid
E Idle speed control valve multi-plug
F Air bypass hose

4.6 Air cleaner housing attachments

A Bolts B Grommet

1595Ford Fiesta Remake

11 On non-Turbo models, disconnect the
flexible hose between the air cleaner lid and
the air inlet duct.
12 On Turbo models, disconnect the idle
speed control valve air bypass hose from the
air inlet duct and the flexible hose between
the air inlet duct and intercooler (see
illustration).
13 Undo the two retaining bolts, and remove
the air inlet duct from the rocker cover.
14 Refitting is the reverse of the removal
procedure.

Accelerator cable - removal,
refitting and adjustment

Removal

1 Disconnect the battery negative (earth) lead
(refer to Chapter 5A, Section 1).
2 Remove the air inlet components as
described in Section 4.
3 Fold back the carpet and insulation in the
driver’s footwell to gain access to the
accelerator pedal.
4 Detach the accelerator cable from the
pedal.
5 Working at the throttle housing end of the
cable, pivot the throttle quadrant by hand to
release the tension from the cable, then
detach the inner cable nipple from the throttle
lever (see illustration).
6 Detach the outer cable from the
adjuster/support bracket, then remove the
cable.

Refitting and adjustment

7 Refit in the reverse order of removal. When
the cable is reconnected at each end, have an

assistant depress the accelerator, and check
that the throttle fully opens and shuts without
binding. Ensure that there is a small amount of
slack in the inner cable when the throttle is
fully released. If adjustment is required,
release the outer cable retaining clip from the
cable at the adjustment/support bracket, slide
the cable through the adjuster grommet to the
point required, then refit the retaining clip to
secure it in the set position.

Accelerator pedal -
removal and refitting

Refer to Part A, Section 5.

Fuel pump/fuel pressure -
checking

Note: Refer to the warning note in Section 1
before proceeding.

Fuel pump operation check

1 Switch on the ignition, and listen for the fuel
pump (the sound of an electric motor running,
audible from beneath the rear seats). Assuming
there is sufficient fuel in the tank, the pump
should start and run for approximately one or
two seconds, then stop, each time the ignition
is switched on. Note: If the pump runs
continuously all the time the ignition is switched
on, the electronic control system is running in
the backup (or “limp-home”) mode referred to
by Ford as “Limited Operation Strategy” (LOS).
This almost certainly indicates a fault in the
EEC IV module itself, and the vehicle should
therefore be taken to a Ford dealer for a full test

of the complete system, using the correct
diagnostic equipment; do not waste time or risk
damaging the components by trying to test the
system without such facilities.
2 Listen for fuel return noises from the fuel
pressure regulator. It should be possible to
feel the fuel pulsing in the regulator and in the
feed hose from the fuel filter.
3 If the pump does not run at all, check the
fuse, relay and wiring (see Chapter 12). Check
also that the fuel cut-off switch has not been
activated and if so, reset it.

Fuel pressure check

4 A fuel pressure gauge will be required for
this check and should be connected in the
fuel line between the fuel filter and the fuel rail,
in accordance with the gauge maker’s
instructions.
5 Disconnect the wiring from the E-DIS
ignition coil and the fuel injectors.
6 Switch the ignition on and off twice, and
check that the pump pressure is as listed in
the Specifications.
7 If the pressure is not as specified, check the
fuel system for leaks or damage. If the system
appears okay, renew the fuel pump.
8 Reconnect the wiring to the ignition coil and
fuel injectors.
9 If the pump pressure was satisfactory, start
the engine and allow it to idle. Disconnect the
vacuum hose at the fuel pressure regulator,
and plug the hose. Note the gauge reading as
soon as the pressure stabilises, and compare
it with the figures given for regulated fuel
pressure in the Specifications.
10 If the regulated fuel pressure is not as
specified, remove the plug from the top of the
fuel pressure regulator, and using a suitable
Allen key, adjust the pressure regulator as
necessary.
11 Switch off the engine, and check that the
fuel pressure stays at the specified hold
pressure for two minutes after the engine is
turned off.
12 Carefully disconnect the fuel pressure
gauge, depressurising the system first as
described in Section 2. Reconnect the ignition
coil and fuel injector wiring.
13 Run the engine, and check that there are
no fuel leaks.

4C•4 Fuel system - electronic fuel injection engines

5.45 Accelerator cable retention

arrangement at the throttle linkage

4.12 Air intake, turbocharger and intercooler details on Turbo models

1595Ford Fiesta Remake

1 Fresh air intake
2 Air cleaner lid
3 Turbocharger
4 Intercooler
5 Air inlet duct
6 Throttle housing
7 Inlet manifold
8 (Hitachi-built) idle

speed control valve

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