Content .. 38 39 40 41 ..

Ford Fiesta (1989-1995). Instruction - part 40

1595Ford Fiesta Remake

General

System type:

1.0, 1.1 and 1.3 litre HCS engines with carburettor . . . . . . . . . . . . . .

Distributorless ignition system (DIS) controlled by ignition module

1.1 and 1.3 litre HCS engines with CFi fuel injection . . . . . . . . . . . . .

Electronic distributorless ignition system (E-DIS) with ignition module
controlled by EEC IV engine management module

1.4 litre CVH engines with carburettor:

Early models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Distributor, with integral ignition amplifier module

Later models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Distributorless ignition system (DIS) controlled by ignition module

1.6 litre CVH engines with carburettor . . . . . . . . . . . . . . . . . . . . . . . .

Distributor, with integral ignition amplifier module

1.4 litre CVH engines with CFi fuel injection:

Pre-September 1990 models . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Distributor, with ignition module, controlled by EEC IV engine
management module

September 1990 models onward . . . . . . . . . . . . . . . . . . . . . . . . . .

Electronic distributorless ignition system (E-DIS) with ignition module
controlled by EEC IV engine management module

1.6 litre CVH engines with EFi fuel injection, and all PTE and Zetec
engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electronic distributorless ignition system (E-DIS) with ignition module
controlled by EEC IV engine management module

Firing order:

HCS engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-2-4-3

All other engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-3-4-2

Location of No 1 cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Crankshaft pulley end

Ignition coil

All engines with distributor ignition systems:

Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30.0 kilovolts (minimum)

Primary resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.72 to 0.88 ohms

Secondary resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4500 to 7000 ohms

All engines with distributorless ignition systems:

Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

37.0 kilovolts (minimum)

Primary resistance (measured at coil tower) . . . . . . . . . . . . . . . . . . . .

0.5 to 1.0 ohm

Distributor

Make:

1.4 and 1.6 litre carburettor models . . . . . . . . . . . . . . . . . . . . . . . . . .

Lucas

1.4 litre CFi fuel injection models (pre-September 1990) . . . . . . . . . .

Bosch

Direction of rotor arm rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Anti-clockwise (viewed from cap)

Automatic advance method:

1.4 and 1.6 litre carburettor models . . . . . . . . . . . . . . . . . . . . . . . . . .

Mechanical and vacuum

1.4 litre CFi fuel injection models (pre-September 1990) . . . . . . . . . .

Totally controlled by EEC IV engine management module

Heat sink compound for ignition amplifier module (Lucas distributor) . .

Ford part number 81 SF-12103-AA

Chapter 5 Part B:
Ignition system

Crankshaft position sensor - removal and refitting . . . . . . . . . . . . . .

Distributor cap and rotor arm - removal and refitting . . . . . . . . . . . .

Distributor vacuum diaphragm unit - renewal . . . . . . . . . . . . . . . . . .

Distributor - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . .

General information and precautions . . . . . . . . . . . . . . . . . . . . . . . .

Ignition coil - checking, removal and refitting . . . . . . . . . . . . . . . . . .

Ignition module - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .

Ignition system - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Ignition timing - checking and adjustment . . . . . . . . . . . . . . . . . . . . 10
Ignition amplifier module (distributor ignition systems) -

removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Spark plug renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1

5B•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

Ignition timing

1.4 and 1.6 litre carburettor models with distributor:

For use with 4-star leaded petrol (97 RON) . . . . . . . . . . . . . . . . . . . .

12° BTDC at idle speed (vacuum pipe disconnected and plugged)

For use with unleaded petrol (95 or 98 RON) . . . . . . . . . . . . . . . . . . .

8° BTDC at idle speed (vacuum pipe disconnected and plugged)

1.4 litre CFi fuel injection models with distributor (pre-Sept 1990) . . . .

10° BTDC at idle speed (set using STAR test equipment - refer to text)

All other models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Totally controlled by ignition module or EEC IV engine management
module

Spark plugs

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

See Chapter 1 Specifications

Torque wrench settings

lbf ft

Crankshaft position sensor (all engines except Zetec) . . . . . . . . . . . . . .

3 to 4

2 to 3

Crankshaft position sensor to bracket (Zetec engines) . . . . . . . . . . . . .

7 to 9

5 to 7

Crankshaft position sensor bracket to engine (Zetec engines) . . . . . . .

18 to 23

13 to 17

DIS/E-DIS ignition coil to bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 to 7

4 to 5

DIS/E-DIS ignition coil bracket to engine (all engines except Zetec) . . .

9 to 12

7 to 9

DIS/E-DIS ignition coil bracket to engine (Zetec engines) . . . . . . . . . . .

18 to 23

13 to 17

5B•2 Ignition system

1595Ford Fiesta Remake

General information and
precautions

General information

The ignition system is responsible for

igniting the air/fuel mixture in each cylinder, at
the correct moment in relation to engine
speed and load, as the electrical spark
generated jumps the spark plug gap.

The ignition system is based on feeding low

tension (LT) voltage from the battery to the
ignition coil where it is converted to high
tension (HT) voltage. The high tension voltage
is powerful enough to jump the spark plug
gap in the cylinders many times a second
under high compression pressures, providing
that the system is in good condition.

A number of different ignition systems have

been fitted to Fiesta models depending on the
year of manufacture, type of fuel system fitted
and the emission level that the vehicle has
been designed to meet. Broadly speaking the
systems can be sub-divided into two
categories - distributor ignition systems and
distributorless ignition systems.

One version of the distributor ignition

system is fitted to all CVH engines with
carburettors. A second (more sophisticated)
version is fitted to pre-September 1990 CVH
engines with CFi fuel injection.

Distributorless ignition systems are fitted to

all HCS, PTE and Zetec engines, and to all
CVH engines with fuel injection except pre-
September 1990 CFi versions.

Distributor ignition systems (CVH
engines with carburettor)

The ignition system is divided into two

circuits; low tension (primary) and high
tension (secondary). The low tension circuit
consists of the battery, ignition switch, coil
primary windings, ignition amplifier module
and the signal generating system inside the

distributor. The signal generating system
comprises the trigger coil, trigger wheel,
stator, permanent magnet and trigger coil to
ignition amplifier module connector. The high
tension circuit consists of the coil secondary
windings, the HT lead from the coil to the
distributor cap, the distributor cap, the rotor
arm, the HT leads from the distributor cap to
the spark plugs and the spark plugs
themselves.

When the system is in operation, low

tension voltage is changed in the coil into high
tension voltage by the action of the electronic
amplifier module in conjunction with the signal
generating system. Any change in the
magnetic field force (flux), created by the
movement of the trigger wheel relative to the
magnet, induces a voltage in the trigger coil.
This voltage is passed to the ignition amplifier
module which switches off the ignition coil
primary circuit. This results in the collapse of
the magnetic field in the coil which
generates the high tension voltage. The high
tension voltage is then fed, via the coil HT
lead and the carbon brush in the centre of the
distributor cap, to the rotor arm. The voltage
passes across to the appropriate metal
segment in the cap and via the spark plug HT
lead to the spark plug where it finally jumps
the spark plug gap to earth.

The distributor is driven by an offset drive

dog locating to a correspondingly offset slot
in the end of the camshaft.

The ignition advance is a function of the

distributor and is controlled both mechanically
and by a vacuum operated system. The
mechanical governor mechanism consists of
two weights which move out from the
distributor shaft as the engine speed rises due
to centrifugal force. As they move outwards,
they rotate the trigger wheel relative to the
distributor shaft and so advance the spark.
The weights are held in position by two light
springs and it is the tension of the springs
which is largely responsible for correct spark
advancement.

The vacuum control consists of a

diaphragm, one side of which is connected
via a small bore hose to the carburettor or
throttle housing, and the other side to the
distributor. Depression in the inlet manifold
and/or carburettor, which varies with engine
speed and throttle position, causes the
diaphragm to move, so moving the stator and
advancing or retarding the spark. A fine
degree of control is achieved by a spring in
the diaphragm assembly.

Additionally, one or more vacuum valve

may be incorporated in the vacuum line
between the inlet manifold or carburettor and
the distributor. The function of these is to
control the vacuum felt at the distributor and
to prevent fuel entering along the vacuum line
(as applicable).

Distributor ignition systems (pre-
September 1990 CVH engines with
CFi fuel injection)

The ignition system is divided into two

circuits; low tension (primary) and high
tension (secondary). The low tension circuit
consists of the battery, ignition switch, ignition
module, ballast resistor, coil primary windings
and “Hall effect” distributor. The high tension
circuit consists of the coil secondary
windings, coil-to-distributor cap HT lead,
distributor cap, rotor arm, spark plug HT leads
and spark plugs. The system is under the
overall control of the EEC IV engine
management module which also controls the
fuel injection and emission control equipment.

When the system is in operation the

distributor supplies the EEC IV module with a
crankshaft position reference signal to enable
an initial ignition timing setting to be
established. This signal is generated by
means of a trigger vane attached to the
distributor shaft and which rotates in the gap
between a permanent magnet and a sensor.
The trigger vane has four cut-outs, one for
each cylinder. When one of the trigger vane
cut-outs is in line with the sensor, magnetic

flux can pass between the magnet and the
sensor. When a trigger vane segment is in line
with the sensor, the magnetic flux is diverted
through the trigger vane, away from the
sensor. The sensor detects the change in
magnetic flux and sends an impulse to the
EEC IV module. Additional data is received
from the engine coolant temperature sensor,
manifold absolute pressure sensor, inlet air
temperature sensor, throttle position sensor
and vehicle speed sensor. Using this
information the EEC IV module calculates the
optimum ignition advance setting and
switches off the low tension circuit via the
ignition module. This results in the collapse of
the magnetic field in the coil which generates
the high tension voltage. The high tension
voltage is then fed, via the coil HT lead and
the carbon brush in the centre of the
distributor cap, to the rotor arm. The voltage
passes across to the appropriate metal
segment in the cap and via the spark plug HT
lead to the spark plug where it finally jumps
the spark plug gap to earth. It can be seen
that the ignition module functions basically as
a high current switch by controlling the low
tension supply to the ignition coil primary
windings.

In the event of failure of a sensor, the

EEC IV module will substitute a preset value
for that input to allow the system to continue
to function. In the event of failure of the
EEC IV module, a “limited operation strategy”
(LOS) function allows the vehicle to be driven,
albeit at reduced power and efficiency. The
EEC IV module also has a “keep alive
memory” (KAM) function which stores idle and
drive values and codes which can be used to
indicate any system fault which may occur.

Distributorless ignition systems

The main ignition system components

include the ignition switch, the battery, the
crankshaft speed/position sensor, the ignition
module, the coil, the primary (low tension/LT)
and secondary (high tension/HT) wiring
circuits, and the spark plugs.

The system used on carburettor models is

termed DIS (Distributorless Ignition System),
and on fuel injection models E-DIS, (Electronic
Distributorless Ignition System). The primary
difference between the two is that the DIS
system is an independent ignition control
system while the E-DIS system operates in
conjunction with the EEC IV engine
management module which also controls the
fuel injection and emission control systems.

With both systems, the main functions of

the distributor are replaced by a computerised
ignition module and a coil unit. The coil unit
combines a double-ended pair of coils - each
time a coil receives an ignition signal, two
sparks are produced, at each end of the
secondary windings. One spark goes to a
cylinder on compression stroke and the other
goes to the corresponding cylinder on its
exhaust stroke. The first will give the correct

power stroke, but the second spark will have
no effect (a “wasted spark”), occurring as it
does during exhaust conditions.

The ignition signal is generated by a

crankshaft position sensor which scans a
series of 36 protrusions on the periphery of
the engine flywheel. The inductive head of the
crankshaft position sensor runs just above the
flywheel periphery and as the crankshaft
rotates, the sensor transmits a pulse to the
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.

On carburettor engines, the ignition module

receives signals provided by information
sensors which monitor various engine
functions (such as crankshaft position,
coolant temperature, inlet air temperature,
inlet manifold vacuum etc). This information
allows the ignition module to generate the
optimum ignition timing setting under all
operating conditions.

On fuel injection engines, the ignition

module operates in conjunction with the
EEC IV engine management module, and
together with the various additional
information sensors and emission control
components, provides total control of the fuel
and ignition systems to form a complete
engine management package.

The information contained in this Chapter

concentrates on the ignition-related
components of the engine management
system. Information covering the fuel, exhaust
and emission control components can be
found in the applicable Parts of Chapter 4.

Precautions

When working on the ignition system, take

the following precautions:

a) Do not keep the ignition switch on for

more than 10 seconds if the engine will
not start.

b) If a separate tachometer is ever required

for servicing work, consult a dealer
service department before buying a
tachometer for use with this vehicle -
some tachometers may be incompatible
with these types of ignition systems - and
always connect it in accordance with the
equipment manufacturer’s instructions.

c) Never connect the ignition coil terminals

to earth. This could result in damage to
the coil and/or the ignition module.

d) Do not disconnect the battery when the

engine is running.

e) Make sure that the ignition module is

properly earthed.

f) Refer to the warning at the beginning of

the next Section concerning HT voltage.

Ignition system - testing

Warning: Voltages produced by
an electronic ignition system are
considerably higher than those
produced by conventional

ignition systems. Extreme care must be
taken when working on the system with
the ignition switched on. Persons with
surgically-implanted cardiac pacemaker
devices should keep well clear of the
ignition circuits, components and test
equipment.

Note: Refer to the precautions given in
Section 1 of Part A of this Chapter before
starting work. Always switch off the ignition
before disconnecting or connecting any
component and when using a multi-meter to
check resistances.

1 If the engine turns over but won’t start,
disconnect the (HT) lead from any spark plug,
and attach it to a calibrated tester (available at
most automotive accessory shops). Connect
the clip on the tester to a good earth - a bolt
or metal bracket on the engine. If you’re
unable to obtain a calibrated ignition tester,
have the check carried out by a Ford dealer
service department or similar. Any other form
of testing (such as jumping a spark from the
end of an HT lead to earth) is not
recommended, because of the risk of
personal injury, or of damage to the ignition
module.
2 Crank the engine, and watch the end of the
tester to see if bright blue, well-defined sparks
occur.
3 If sparks occur, sufficient voltage is
reaching the plug to fire it. Repeat the
check at the remaining plugs, to ensure
that all leads are sound and that the
coil is serviceable. However, the plugs
themselves may be fouled or faulty, so
remove and check them as described in
Chapter 1.
4 If no sparks or intermittent sparks occur,
the spark plug lead(s) may be defective. Also,
on distributor systems, there may be
problems with the rotor arm or distributor cap
- check all these components as described in
Chapter 1.
5 If there’s still no spark, check the coil’s
electrical connector (where applicable), to
make sure it’s clean and tight. Check for full
battery voltage to the coil at the connector’s
centre terminal. Check the coil itself (see
Section 3). Make any necessary repairs, then
repeat the check again.
6 The remainder of the system checks should
be left to a dealer service department
or other qualified repair facility, as there is a
chance that the ignition module may
be damaged if tests are not performed
properly.

Ignition system 5B•3

1595Ford Fiesta Remake

Ignition coil - checking,
removal and refitting

Distributor ignition systems

Checking

1 Accurate checking of the coil output
requires the use of special test equipment and
should be left to a dealer or suitably equipped
automotive electrician. It is however possible
to check the primary and secondary winding
resistance using an ohmmeter as follows.
2 Disconnect the battery negative (earth) lead
(refer to Part A, Section 1).
3 Remove the vehicle jack from its storage
position by unscrewing its retainer. The
ignition coil is mounted below.
4 To check the primary resistance (with all
leads disconnected if the coil is fitted),
connect the ohmmeter across the coil positive
and negative terminals. The resistance should
be as given in the Specifications at the
beginning of this Chapter.
5 To check the secondary resistance (with all
leads disconnected if the coil is fitted),
connect one lead from the ohmmeter to the
coil negative terminal, and the other lead to
the centre HT terminal. Again the resistance
should be as given in the Specifications.
6 If any of the measured values vary
significantly from the figures given in the
Specifications, the coil should be renewed.
7 If a new coil is to be fitted, ensure that it is
of the correct type. The appropriate Ford
supplied ignition coil is identified by a red
label, and will be one of three different makes,
all of which are fully interchangeable. Bosch
and Femsa coils are fitted with protective
plastic covers, and Polmot coils are fitted with
an internal fusible link. Note that contact
breaker ignition coils are not interchangeable
with the required breakerless type and could
cause ignition module failure if used.

Removal

8 If not already done, remove the vehicle jack

from its storage position by unscrewing its
retainer. The ignition coil is mounted below.
9 Disconnect the battery negative (earth) lead
(refer to Part A, Section 1).
10 Disconnect the HT lead and the low
tension (LT) connections from the ignition coil.
Note that the LT connections on the ignition
coil are of different sizes. As an aid to refitting
the positive (+) terminal is larger than the
negative (-) terminal (see illustration).
11 Remove the two screws or bolts securing
the coil mounting bracket to the inner wing
panel, and withdraw the coil and mounting
bracket assembly.

Refitting

12 Refitting is a reversal of the removal
procedure, ensuring correct LT lead polarity.

Distributorless ignition systems

Checking

Note: The ignition coil is located on the rear
facing side of the cylinder block on HCS
engines; on the left-hand end of the cylinder
head on CVH, PTE and Zetec engines.
13 Having checked that full battery voltage is
available at the centre terminal of the coil’s
electrical connector (see Section 2),
disconnect the battery negative (earth) lead
(refer to Part A, Section 1).
14 Unplug the coil’s electrical connector, if
not already disconnected.
15 Using an ohmmeter, measure the
resistance of the coil’s primary windings,
connecting the meter between the coil’s
terminal pins as follows. Measure first from
one outer pin to the centre pin, then from the
other outer pin to the centre. Compare the
readings with the coil primary resistance listed
in the Specifications.
16 Disconnect the spark plug (HT) leads -
note their connections or label them carefully,
as described in Chapter 1. Use the meter to
check that there is continuity between each
pair of (HT) lead terminals; Nos 1 and 4
terminals are connected by their secondary
winding, as are Nos 2 and 3. Now switch to

the highest resistance scale, and check that
there is no continuity between either pair of
terminals and the other - ie, there should be
infinite resistance between terminals 1 and 2,
or 4 and 3 - and between any terminal and
earth.
17 If either of the above tests yield resistance
values outside the specified amount, or
results other than those described, renew the
coil. Any further testing should be left to a
dealer service department or other qualified
repair facility.

Removal

Note: The ignition coil is located on the rear
facing side of the cylinder block on HCS
engines; on the left-hand end of the cylinder
head on CVH, PTE and Zetec engines.
18 Disconnect the battery negative (earth)
lead (refer to Part A, Section 1).
19 Disconnect the coil main electrical
connector and (where fitted) the electrical
connector to the suppressor.
20 The coil can be removed with the HT
leads left attached, in which case disconnect
the leads from their respective spark plugs
and from the location clips in the rocker cover
or air inlet duct (as applicable). If preferred,
the HT leads can be disconnected from the
coil. First check that both the ignition HT
leads and their fitted positions are clearly
marked numerically to ensure correct refitting.
Spot mark them accordingly if necessary,
using quick-drying paint.
21 If disconnecting the leads from the spark
plugs, pull them free by gripping on the
connector, not the lead. To detach the leads
from the ignition coil, compress the retaining
arms of each lead connector at the coil, and
detach each lead in turn (see illustration).
22 Unscrew the Torx-type retaining screws,
and remove the coil from its mounting on the
engine (see illustration).

Refitting

23 Refitting is the reverse of the removal
procedure. Ensure that the spark plug (HT)
leads are correctly reconnected, and tighten
the coil screws securely.

5B•4 Ignition system

3.22 Distributorless ignition system ignition

coil and mounting bracket removal (HCS

engine shown)

3.21 Removing an HT lead from the

distributorless ignition system ignition coil.

Note the corresponding markings on the

ignition coil and HT lead (arrowed)

3.10 Ignition coil fitted to distributor

ignition systems

A Retaining bolts
B LT connections
C HT lead to distributor cap

1595Ford Fiesta Remake

Content .. 38 39 40 41 ..