1989 FORD FIESTA fuel pressure

7 Fuel pump/fuel pressure-
checking
3
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. On Zetec engines, a pressure
gauge equipped with an adapter to suit the
Schrader-type valve on the fuel rail pressure
test/release fitting (identifiable by its blue
plastic cap, and located on the union of the
fuel feed line and the fuel rail) will be required.
If the Ford special tool 29-033 is available, the
tool can be attached to the valve, and a
conventional-type pressure gauge attached to
the tool.
5 If using the service tool, ensure that its tap
is turned fully anti-clockwise, then attach it to
the valve. Connect the pressure gauge to the
service tool. If using a fuel pressure gauge
with its own adapter, connect it in accordance
with its maker’s instructions.
6 Start the engine and allow it to idle. Note
the gauge reading as soon as the pressure
stabilises, and compare it with the regulated
fuel pressure figures listed in the
Specifications .
a) If the pressure is high, check for a
restricted fuel return line. If the line is
clear, renew the fuel pressure regulator.
b) If the pressure is low, pinch the fuel return
line. If the pressure now goes up, renew the fuel pressure regulator. If the pressure
does not increase, check the fuel feed
line, the fuel pump and the fuel filter.
7 Detach the vacuum hose from the fuel
pressure regulator; the pressure shown on the
gauge should increase. Note the increase in
pressure, and compare it with that listed in the
Specifications . If the pressure increase is not
as specified, check the vacuum hose and
pressure regulator.
8 Reconnect the regulator vacuum hose, and
switch off the engine. Verify that the hold
pressure stays at the specified level for five
minutes after the engine is turned off.
9 Carefully disconnect the fuel pressure
gauge, depressurising the system first as
described in Section 2. Be sure to cover the
fitting with a rag before slackening it. Mop up
any spilt petrol.
10 Run the engine, and check that there are
no fuel leaks.
8 Fuel tank - removal,
inspection and refitting
3
Proceed as described in Part A, Section 8,
but before disconnecting the battery, relieve
the residual pressure in the fuel system (see
Section 2), and equalise tank pressure by
removing the fuel filler cap.
9 Fuel pump/fuel gauge sender unit - removal and
refitting
3
Refer to Part B, Section 9.
10 Fuel tank ventilation tube -
removal and refitting
3
Refer to Part A, Section 10, but note that
the ventilation tube connects to the combined
roll-over/anti-trickle-fill valve assembly but,
instead of venting to atmosphere, a further
tube runs the length of the vehicle to the
evaporative emission control system carbon canister in the front right-hand corner of the
engine compartment.
Further information on the evaporative
emission control system is contained in Part E
of this Chapter.
11 Fuel tank filler pipe -
removal and refitting
3
Refer to Part A, Section 11.
12 Fuel cut-off switch -
removal and refitting
1
Refer to Part B, Section 12.
13 Fuel injection system -
checking
3
Refer to Part B, Section 13
14 Fuel injection system components - removal and
refitting
3
Note: Refer to the warning note in Section 1
before proceeding.
Throttle housing
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 Disconnect the accelerator cable from the
throttle linkage (see Section 5).
4 Disconnect the throttle position sensor
multi-plug.
5 Unscrew the retaining bolts, and detach the
accelerator cable support bracket at the
throttle housing (see illustration) .
6 Unscrew the throttle housing-to-manifold
retaining bolts (see illustration) , and unbolt
the throttle housing support bracket bolts
(where fitted). Remove the throttle housing
4D•4 Fuel system - sequential electronic fuel injection engines
14.6 Throttle housing retaining bolts
(arrowed)14.5 Unscrew the retaining bolts (arrowed),and detach the accelerator cable support
bracket
1595Ford Fiesta Remakeprocarmanuals.com
http://vnx.su

and gasket. Discard the gasket - this must be
renewed whenever it is disturbed.
7Refit in the reverse order of removal. Check
that the mating faces are clean, and fit a new
gasket. Adjust the accelerator cable as
described in Section 5 on completion.
Fuel rail and injectors
Note: The following procedure is applicable
mainly to Zetec engines; specific information
for the PTE engine was not available at the
time of writing. However, apart from minor
differences in component attachments, both
engine types are very similar in this area.
8 Relieve the residual pressure in the fuel
system (see Section 2), and equalise tank
pressure by removing the fuel filler cap. Warning: This procedure will
merely relieve the increased
pressure necessary for the
engine to run - remember that
fuel will still be present in the system
components, and take precautions
accordingly before disconnecting any of
them.
9 Disconnect the battery negative (earth) lead
- see Chapter 5A, Section 1.
10 Remove the air inlet components as
described in Section 4.
11 Disconnect the accelerator cable from the
throttle linkage (see Section 5).
12 Disconnect the throttle position sensor
multi-plug.
13 Remove the throttle housing mounting
screws, then detach the throttle housing and gasket from the inlet manifold. Discard the
gasket - this must be renewed whenever it is
disturbed.
14
Detach the crankcase breather hose from
the cylinder head cover, and the fuel pressure
regulator vacuum hose from the inlet
manifold.
15 Releasing the wire clips, unplug the four
fuel injector multi-plugs and the inlet air
temperature sensor multi-plug.
16 Refer to Section 3 and disconnect the fuel
feed and return lines at the quick-release
couplings, then unclip the fuel hoses from the
inlet manifold; use rag to soak up any spilt
fuel. Note: Do not disturb the threaded
couplings at the fuel rail unions unless
absolutely necessary; these are sealed at the
factory. The quick-release couplings will
suffice for all normal service operations.
17 Unscrew the three bolts securing the fuel
rail (see illustration) . Withdraw the rail,
carefully prising it out of the inlet manifold,
and draining any remaining fuel into a suitable
clean container. Note the seals between the
rail noses and the manifold; these must be
renewed whenever the rail is removed (see
illustration) .
18 Clamping the rail carefully in a vice fitted
with soft jaws, unscrew the two bolts securing
each injector, and withdraw the injectors (see
illustration) . Place each in a clean, clearly-
labelled storage container.
19 If the injector(s) are being renewed,
discard the old injector, the nose seal and the
O- rings. If only the injector O-rings are being renewed, and it is intended that the same
injectors will be re-used, remove the old nose
seal and O-rings, and discard them.
20
Refitting is the reverse of the removal
procedure, noting the following points:
a) Lubricate each nose seal and O-ring with clean engine oil on installation.
b) Locate each injector carefully in the fuel
rail recess, ensuring that the locating tab
on the injector head fits into the slot
provided in the rail. Tighten the bolts
securely.
c) Fit a new seal to each fuel rail nose, and
ensure that the seals are not displaced as
the rail is refitted (see illustration).
Ensure that the fuel rail is settled fully in
the manifold before tightening the bolts.
d) Ensure that the hoses and wiring are
routed correctly, and secured on
reconnection by any clips or ties
provided.
e) Adjust the accelerator cable as described
in Section 5.
f) On completion, switch the ignition on and off five times, to activate the fuel pump
and pressurise the system, without
cranking the engine. Check for signs of
fuel leaks around all disturbed unions and
joints before attempting to start the
engine.
Fuel pressure regulator
21 Relieve the residual pressure in the fuel
system (see Section 2), and equalise tank
pressure by removing the fuel filler cap.
Warning: This procedure will
merely relieve the increased
pressure necessary for the
engine to run - remember that
fuel will still be present in the system
components, and take precautions
accordingly before disconnecting any of
them.
22 Disconnect the battery negative (earth)
lead - see Chapter 5A, Section 1.
23 Disconnect the vacuum hose from the
regulator.
24 Unscrew the two regulator retaining bolts
(see illustration) then use a wad of clean rag
to soak up any spilt fuel, and withdraw the
regulator.
Fuel system - sequential electronic fuel injection engines 4D•5
14.18 Removing an injector from the fuel rail. Note the O-ring seals (arrowed)14.17b Note nose seals (arrowed) between rail and intermediate flange14.17a Unscrewing fuel rail mounting bolts (arrowed)
14.24 Fuel pressure regulator vacuumhose (A) and retaining bolts (B)14.20 Fit new nose seals (arrowed) before refitting the fuel rail
4D
1595Ford Fiesta Remakeprocarmanuals.com
http://vnx.su

b)Tighten the screws evenly and securely
(but do not overtighten them, or the
potentiometer body will be cracked).
Vehicle speed sensor
48 The sensor is mounted at the base of the
speedometer drive cable, and is removed with
the speedometer drive pinion. Refer to the
relevant Section of Chapter 7A or B, as
applicable.
Power steering pressure switch
49 Releasing its clip, unplug the switch’s
electrical connector, then unscrew the switch
from the power steering high pressure pipe.
Place a wad of rag underneath, to catch any
spilt fluid. If a sealing washer is fitted, renew it
if it is worn or damaged.
50 Refitting is the reverse of the removal
procedure; tighten the switch securely, then
top-up the fluid reservoir (see “Weekly
Checks”) to replace any fluid lost from the
system, and bleed out any trapped air (see
Chapter 10).
Oxygen sensor
Note: The sensor is delicate, and will not work
if it is dropped or knocked, if its power supply
is disrupted, or if any cleaning materials are
used on it.
51 Raise and support the front of the vehicle
if required to remove the sensor from
underneath (“see Jacking and vehicle
support” ).
52 Release the sensor’s wiring multi-plug
from its support bracket, and unplug it to
disconnect the sensor (see illustration).
53 Unscrew the sensor from the exhaust
system front downpipe; collect the sealing
washer (where fitted).
54 On refitting, clean the sealing washer
(where fitted) and renew it if it is damaged or
worn. Apply a smear of anti-seize compound
to the sensor’s threads, to prevent them from
welding themselves to the downpipe in
service. Refit the sensor, tightening it to its
specified torque wrench setting; a slotted
socket will be required to do this. Reconnect
the wiring, and refit the connector plug.
15 Inlet manifold -
removal and refitting
4
Note: Refer to the warning note in Section 1
before proceeding.
Removal
PTE engines
1 The inlet manifold is a two-piece assembly
comprising an upper and lower section bolted
together.
2 Drain the cooling system with reference to
Chapter 1.
3 Relieve the residual pressure in the fuel
system (see Section 2), and equalise tank
pressure by removing the fuel filler cap. Warning: This procedure will
merely relieve the increased
pressure necessary for the engine
to run - remember that fuel will
still be present in the system components,
and take precautions accordingly before
disconnecting any of them.
4 Disconnect the battery negative (earth) lead
(refer to Chapter 5A, Section 1).
5 Remove the air inlet components (Sec-
tion 4) and disconnect the accelerator cable
from the throttle linkage (Section 5).
6 Remove the fuel injectors and fuel rail as
described in Section 14.
7 Noting their locations, disconnect the
coolant, vacuum and breather hoses from the
manifold. 8
Disconnect the wiring multi-plugs from the
engine sensors at the inlet manifold.
9 Undo the retaining bolts, and withdraw the
manifold from the cylinder head. Note the
location of the engine lifting bracket and earth
lead, where fitted. Remove the gasket.
10 With the manifold removed, clean all
traces of the old gasket from the mating
surfaces of the manifold and the cylinder
head.Zetec engines
11 Relieve the residual pressure in the fuel
system (see Section 2), and equalise tank
pressure by removing the fuel filler cap. Warning: This procedure will
merely relieve the increased
pressure necessary for the
engine to run - remember that
fuel will still be present in the system
components, and take precautions
accordingly before disconnecting any of
them.
12 Disconnect the battery negative (earth)
lead (refer to Chapter 5A, Section 1).
13 Remove the air inlet components (Sec-
tion 4) and disconnect the accelerator cable
from the throttle linkage (Section 5).
14 Disconnect the crankcase breather hose
from the cylinder head cover union.
15 Unbolt the upper part of the exhaust
manifold heat shield.
16 Remove the two screws securing the
wiring “rail” to the top of the manifold - this is
simply so that it can be moved as required to
reach the manifold bolts (see illustration).
Fuel system - sequential electronic fuel injection engines 4D•7
14.52 Oxygen sensor (A) and wiring multi-
plug (B) (Zetec engine shown)15.16 Exploded view of the Zetec engine inlet manifold components
4D
1595Ford Fiesta Remake
1 Cylinder head
cover
2 Heat-insulating plate/gasket
3 Intermediate flange/fuel rail
assembly
4 Gasket
5 Inlet manifold
6 Intake air temperature
sensor
7 Engine wiring
loom
8 Boltsprocarmanuals.com
http://vnx.su

Unplug the electrical connectors at the
camshaft position sensor and the coolant
temperature sensor, then unclip the wiring
from the ignition coil bracket, and secure it to
the manifold.
17Remove the three screws securing the
wiring “rail” to the rear of the manifold.
Releasing its wire clip, unplug the large
electrical connector (next to the fuel pressure
regulator) to disconnect the wiring of the
manifold components from the engine wiring
loom.
18 Marking or labelling them as they are
unplugged, disconnect the vacuum hoses at
the manifold and throttle housing.
19 Undo the fuel feed and return lines
connecting the engine to the chassis. Plug or
cap all open fittings. 20
Unbolt the earth lead from the cylinder
head rear support plate/engine lifting eye,
then unscrew the bolt securing the support
plate/lifting eye.
21 Unscrew the nuts and bolts securing the
manifold to the cylinder head, and withdraw it.
Take care not to damage vulnerable
components as the manifold assembly is
manoeuvred out of the engine compartment.
22 With the manifold removed, clean all
traces of the old gasket from the mating
surfaces of the manifold and the cylinder head.
Refitting
All engines
23 Refitting is the reverse of the removal
procedure, noting the following points: a) Fit a new gasket, then locate the manifold on the head and install the nuts and bolts.
b) Tighten the nuts/bolts in three or four
equal steps to the specified torque,
working from the centre outwards, to
avoid warping the manifold.
c) Refit the remaining parts in the reverse order of removal - tighten all fasteners to
the torque wrench settings specified
(where given).
d) Where drained, refill the cooling system
as described in Chapter 1.
e) Before starting the engine, check the accelerator cable for correct adjustment
and the throttle linkage for smooth
operation (Section 5).
f) When the engine is fully warmed-up,
check for signs of fuel, inlet and/or
vacuum leaks.
4D•8 Fuel system - sequential electronic fuel injection engines
1595Ford Fiesta Remakeprocarmanuals.com
http://vnx.su

into the engine induction system and thence
into the combustion chambers. This
arrangement eliminates any fuel mixture
control problems. The operating principles for
the system used on the Endura-E engine are
basically the same as just described with
revisions to the component locations and
hose arrangement.On CVH and PTE engines, a closed-circuit
type crankcase ventilation system is used, the
function of which is basically the same as that
described for the HCS engine type, but the
breather hose connects directly to the rocker
cover. The oil filler cap incorporates a
separate filter in certain applications. On Zetec engines, the crankcase ventilation
system main components are the oil
separator mounted on the front (radiator) side
of the cylinder block/crankcase, and the
Positive Crankcase Ventilation (PCV) valve set
in a rubber grommet in the separator’s left-
hand upper end. The associated pipework
consists of a crankcase breather pipe and two
flexible hoses connecting the PCV valve to a
union on the left-hand end of the inlet
manifold, and a crankcase breather hose
connecting the cylinder head cover to the air
cleaner assembly. A small foam filter in the air
cleaner prevents dirt from being drawn
directly into the engine.
Evaporative emissions control system
This system is fitted to minimise the escape
of unburned hydrocarbons into the
atmosphere. Fuel evaporative emissions
control systems are limited on vehicles
meeting earlier emissions regulations;
carburettor float chambers are vented
internally, whilst fuel tanks vent to atmosphere
through a combined roll-over/anti-trickle-fill
valve. On vehicles meeting the more stringent
emissions regulations, the fuel tank filler cap
is sealed, and a charcoal canister is used to
collect and store petrol vapours generated in
the tank when the vehicle is parked. When the
engine is running, the vapours are cleared
from the canister (under the control of the
EEC IV engine management module via the
canister-purge solenoid valve) into the inlet
tract, to be burned by the engine during
normal combustion. To ensure that the engine runs correctly
when it is cold and/or idling, and to protect
the catalytic converter from the effects of an
over-rich mixture, the canister-purge solenoid
valve is not opened by the EEC IV module
until the engine is fully warmed-up and
running under part-load; the solenoid valve is
then switched on and off, to allow the stored
vapour to pass into the inlet tract.
Pulse-air system
This system consists of the pulse-air
solenoid valve, the pulse-air valve itself, the
delivery tubing, a pulse-air filter, and on some
models, a check valve. The system injects
filtered air directly into the exhaust ports,
using the pressure variations in the exhaust
gases to draw air through from the filter housing; air will flow into the exhaust only
when its pressure is below atmospheric. The
pulse-air valve can allow gases to flow only
one way, so there is no risk of hot exhaust
gases flowing back into the filter.
The system’s primary function is raise
exhaust gas temperatures on start-up, thus
reducing the amount of time taken for the
catalytic converter to reach operating
temperature. Until this happens, the system
reduces emissions of unburned hydrocarbon
particles (HC) and carbon monoxide (CO) by
ensuring that a considerable proportion of
these substances remaining in the exhaust
gases after combustion are burned up, either
in the manifold itself or in the catalytic
converter.
To ensure that the system does not upset
the smooth running of the engine under
normal driving conditions, it is linked by the
pulse-air solenoid valve to the EEC IV module,
so that it only functions during engine warm-
up, when the oxygen sensor is not influencing
the fuel/air mixture ratio.
Catalytic converter
Catalytic converters have been introduced
progressively on all models in the range, to
meet the various emissions regulations.
The catalytic converter is located in the
exhaust system, and operates in conjunction
with an exhaust gas oxygen sensor to reduce
exhaust gas emissions. The catalytic
converter uses precious metals (platinum and
palladium or rhodium) as catalysts to speed
up the reaction between the pollutants and
the oxygen in the vehicle’s exhaust gases, CO
and HC being oxidised to form H
2O and CO2and (in the three-way type of catalytic
converter) NO
xbeing reduced to N2. Note :
The catalytic converter is not a filter in the
physical sense; its function is to promote a
chemical reaction, but it is not itself affected
by that reaction. The converter consists of an element (or
“substrate”) of ceramic honeycomb, coated
with a combination of precious metals in such
a way as to produce a vast surface area over
which the exhaust gases must flow; the whole
being mounted in a stainless-steel box. A
simple “oxidation” (or “two-way”) catalytic
converter can deal with CO and HC only,
while a “reduction” (or “three-way”) catalytic
converter can deal with CO, HC and NO
x.
Three-way catalytic converters are further
sub-divided into “open-loop” (or
“unregulated”) converters, which can remove
50 to 70% of pollutants and “closed-loop”
(also known as “controlled” or “regulated”)
converters, which can remove over 90% of
pollutants.
In order for a closed-loop catalytic
converter to operate effectively, the air/fuel
mixture must be very accurately controlled,
and this is achieved by measuring the oxygen
content of the exhaust gas. The oxygen
sensor transmits information on the exhaust
gas oxygen content to the EEC IV engine management module, which adjusts the
air/fuel mixture strength accordingly.
The sensor has a built-in heating element
which is controlled by the EEC IV module, in
order to bring the sensor’s tip to an efficient
operating temperature as rapidly as possible.
The sensor’s tip is sensitive to oxygen, and
sends the module a varying voltage
depending on the amount of oxygen in the
exhaust gases; if the inlet air/fuel mixture is
too rich, the sensor sends a high-voltage
signal. The voltage falls as the mixture
weakens. Peak conversion efficiency of all
major pollutants occurs if the inlet air/fuel
mixture is maintained at the chemically-
correct ratio for the complete combustion of
petrol - 14.7 parts (by weight) of air to 1 part
of fuel (the “stoichiometric” ratio). The sensor
output voltage alters in a large step at this
point, the module using the signal change as
a reference point, and correcting the inlet
air/fuel mixture accordingly by altering the fuel
injector pulse width (injector opening time). Removal and refitting procedures for
the oxygen sensor are given in Parts B, C
and D of this Chapter according to fuel
system type.
2 Exhaust system - renewal
2
Warning: Inspection and repair
of exhaust system components
should be done only after
enough time has elapsed after
driving the vehicle to allow the system
components to cool completely. This
applies particularly to the catalytic
converter, which runs at very high
temperatures. Also, when working under
the vehicle, make sure it is securely
supported on axle stands.
If the exhaust system components are
extremely corroded or rusted together, they
will probably have to be cut from the exhaust
system. The most convenient way of
accomplishing this is to have a quick-fit
exhaust repair specialist remove the corroded
sections. Alternatively, you can simply cut off
the old components with a hacksaw. If you do
decide to tackle the job at home, be sure to
wear eye protection, to protect your eyes from
metal chips, and work gloves, to protect your
hands. If the production-fit system is still
fitted, it must be cut for the service-
replacement system sections to fit. The best
way of determining the correct cutting point is
to obtain the new centre or rear section first
then, with the old system removed, lay the
two side by side on the ground. It should now
be relatively easy to determine where the old
system needs to be cut, and it can be marked
accordingly. Remember to allow for the
overlap where the two sections will plug
together.
4E•2 Exhaust and emission control systems
1595Ford Fiesta Remakeprocarmanuals.com
http://vnx.su

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 settingsNmlbf 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
1 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
procarmanuals.com
http://vnx.su

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.
2 Ignition system - testing
2
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
5B
1595Ford Fiesta Remakeprocarmanuals.com
http://vnx.su

39With the drivebelt tensioned correctly,
tighten the pivot and adjuster bolts to the
specified torque. Re-check the tension of the
drivebelt after tightening the bolts.
40 Reconnect the rigid brake pipes to the
modulator, tightening the unions to seal the
system.
41 Refit the modulator drivebelt cover and
secure with its two retaining bolts. Take care
not to damage the driveshaft CV joint gaiter as
the cover is eased into position.
42 Refit the belt-break switch to the
modulator drivebelt cover, taking care not to
damage the belt contact arm as it passes
through the cover.
43 Reconnect the modulator return hose by
pushing the hose firmly into its brake fluid
reservoir location, then lever out the collar to
retain it.
44 Refit the front suspension crossmember
and the one-piece undertray, as applicable.
45 Refit the roadwheels, then remove the
axle stands and lower the vehicle to the
ground. Tighten the wheel nuts to the
specified torque.
46 Top-up the brake fluid reservoir using
fresh fluid of the specified type (see “ Weekly
checks ”), then bleed the brake hydraulic
system in accordance with Section 14. Refit
the reservoir filler cap and the warning
indicator wiring multi-plug on completion.
47 Reconnect the battery negative lead.
Modulator drivebelt
48Disconnect the battery negative (earth)
lead (refer to Chapter 5A, Section 1).
49 Chock the rear wheels then jack up the
front of the car and support it on axle stands
(see “Jacking and Vehicle Support” ). Remove
the relevant front roadwheel.
50 Remove the one-piece undertray where
fitted, by turning its bayonet-type fasteners,
and on XR2i models, remove the front
suspension crossmember (see Chapter 10).
51 Remove the belt-break switch from the
relevant drivebelt cover, then remove the
drivebelt cover, as described in the previous
sub-Section.
52 Slacken the modulator pivot and adjuster
bolts to release drivebelt tension, then slip the
drivebelt from the modulator.
53 Remove the track rod end balljoint from
the steering arm on the spindle carrier (see
Chapter 10).
54 Disconnect the anti-roll bar connecting
link (where applicable) and release the brake
hose from their locations on the suspension
strut.
55 Remove the pinch bolt and nut securing
the lower suspension arm balljoint to the
spindle carrier, and separate the balljoint from
the spindle carrier assembly.
56 To release the driveshaft inner CV joint
from the differential, have an assistant pull the
spindle carrier away from the centre of the
vehicle whilst you insert a lever between the
inner CV joint and the transmission casing,
then firmly strike the lever with the flat of the hand, but be careful not to damage adjacent
components. Make provision for escaping
transmission oil, if possible plugging the
opening to prevent excessive loss. Do not
allow the CV joints to bend more than 20°
from the horizontal or internal damage may
occur. If both driveshafts are to be removed,
immobilise the differential by inserting an old
joint or suitable shaft, before the other
driveshaft is removed.
57
Slide the drivebelt off the driveshaft.
58 Remove the snap-ring from the groove in
the splines of the inner CV joint. This snap-
ring must be renewed every time the
driveshaft is withdrawn from the differential.
59 With the drivebelt removed, closely
examine the condition of the belt over its
entire length. Renew the belt if any cracks are
noticed in the fabric at the roots of the teeth, if
there is any abrasion of the fabric facing
material, or if there are any tears starting from
the edge of the belt.
60 If, since the drivebelts were last renewed,
a vehicle has covered more than 30 000 miles
(48 000 km) or a period of more than two
years has elapsed, the drivebelts should be
renewed as a matter of course.
61 Prior to refitting the drivebelt, thoroughly
clean its CV joint pulley location.
62 Fit the drivebelt over the driveshaft then,
with a new snap-ring fitted to the inner CV
joint splines, lubricate the splines with
transmission oil. Remove the temporary plug
and insert the inner CV joint to its
transmission casing location. Press against
the spindle carrier so that the snap-ring
engages fully to hold the CV joint splines in
the differential.
63 Refitting is now a reversal of the removal
procedure, tensioning the drivebelt as
described in the previous sub-Section. Ensure
that the pinch-bolt securing the lower
suspension arm balljoint to the spindle carrier
locates in the annular groove on the balljoint
spindle. Secure the track rod and balljoint,
using a new split pin. Tighten the suspension
components to their specified torque (see
Chapter 10).
64 Check the level of the transmission oil,
and top-up as required (see Chapter 1).
Modulator belt-break switch
65 Modulator belt-break switches are fitted
to each of the two drivebelt covers, and clip
into position. To remove, gently squeeze the
protruding lever on the switch towards the
main switch body and lift out, ensuring that
the belt contact arm does not catch on the
drivebelt cover.
25 Load-apportioning valve (ABS models) - adjustment
3
1Before attempting to adjust the load-
apportioning valves, the vehicle must be at its
kerb weight, ie with approximately half a tank
of fuel and carrying no load. Note that a
special setting tool will be required to adjust
the valves - this can be fabricated, to the
dimensions shown (see illustration).
2 Raise the vehicle on ramps or drive it over
an inspection pit, so that working clearance is
obtained with the full weight of the vehicle
resting on its roadwheels. Remove the spare
wheel and its carrier.
3 To check adjustment, insert the load-
apportioning valve setting tool into the nylon
sleeve without pre-loading the valve. If unable
to insert the tool, carry out the following
adjustment procedure.
4 Slacken the operating link adjustment fixing
screw then insert the setting tool into the
nylon sleeve, applying light pressure to the
operating link upper arm, so that the setting
tool fully locates. With the setting tool just
resting up against the adjustment post,
tighten the operating link adjustment fixing
screw to the specified torque (see
illustration) .
5 Repeat the procedure on the other valve.
6 Refit the spare wheel on completion.
26 Load-apportioning valve
(ABS models) - removal and
refitting
3
1 Minimise hydraulic fluid loss by
disconnecting the wiring multi-plug from the
fluid level warning indicator in the master
9•16 Braking system
25.4 Load-apportioning valve adjustment
A Setting tool
B Operating link adjustment fixing screw
C Adjustment post
25.1 Load-apportioning valve adjustment tool (dimensions given in mm)
1595Ford Fiesta Remakeprocarmanuals.com
http://vnx.su