1993 FORD MONDEO air filter

This Chapter is concerned with those
features of the engine management system
that supply clean fuel and air to the engine,
meter it in the required proportions, and
dispose of the results. Since the emission
control sub-systems modify the functions of
both the fuel and exhaust sub-systems, all of
which are integral parts of the whole engine
management system, there are many cross-
references to Chapters 5 and 6. Information
on the electronic control system, its fault
diagnosis, sensors and actuators, is given in
Chapter 6.
The air intake system consists of several
plastics components designed to eliminate
induction roar as much as possible. The air
intake tube (opening behind the direction
indicator/headlight assembly) is connected,
via small and large resonators located under
the front left-hand wing, to the air cleaner
assembly in the engine compartment. Once it
has passed through the filter element and the
air mass meter, the air enters the plenum
chamber mounted above the throttle housing
and inlet manifold; the resonator mounted in
the engine compartment further reduces noise
levels.
The fuel system consists of a plastic tank
(mounted under the body, beneath the rear
seats), combined metal and plastic fuel hoses,
an electric fuel pump mounted in the fuel tank,
and an electronic fuel injection system.
The exhaust system consists of an exhaust
manifold, the front downpipe and catalytic
converter and, on production-fit systems, a
rear section incorporating two or three
silencers and the tailpipe assembly. The
service replacement exhaust system consists
of three or four sections: the front
downpipe/catalytic converter, the
intermediate pipe and front silencer, and the
tailpipe and rear silencer. On some versions,
the tailpipe is in two pieces, with two rear
silencers. The system is suspended
throughout its entire length by rubber
mountings.
Extreme caution should be exercised when
dealing with either the fuel or exhaust
systems. Fuel is a primary element for
combustion. Be very careful! The exhaust
system is an area for exercising caution, as it
operates at very high temperatures. Serious
burns can result from even momentary
contact with any part of the exhaust system,
and the fire risk is ever-present. The catalytic
converter in particular runs at very high
temperatures - refer to the information in
Chapter 6.
Warning: Many of the procedures
in this Chapter require the
removal of fuel lines and
connections, which may result in
some fuel spillage. Petrol is extremely
flammable, so take extra precautionswhen you work on any part of the fuel
system. Don’t smoke, or allow open flames
or bare light bulbs, near the work area.
Don’t work in a garage where a natural
gas-type appliance (such as a water
heater or clothes dryer) with a pilot light is
present. If you spill any fuel on your skin,
rinse it off immediately with soap and
water. When you perform any kind of work
on the fuel system, wear safety glasses,
and have a Class B type fire extinguisher
on hand. Before carrying out any operation
on the fuel system, refer also to the
precautions given in “Safety first!” at the
beginning of this manual, and follow them
implicitly. Petrol is a highly-dangerous and
volatile liquid, and the precautions
necessary when handling it cannot be
overstressed.
Warning: The fuel system will
remain pressurised for long
periods of time after the engine is
switched off - this pressure must
be released before any part of the system
is disturbed. Petrol is extremely
flammable, so take extra precautions
when you work on any part of the fuel
system. Don’t smoke, or allow open flames
or bare light bulbs, near the work area.
Don’t work in a garage where a natural
gas-type appliance (such as a water
heater or clothes dryer) with a pilot light is
present. If you spill any fuel on your skin,
rinse it off immediately with soap and
water. When you perform any kind of work
on the fuel system, wear safety glasses,
and have a Class B type fire extinguisher
on hand.
1The fuel system referred to in this Chapter
is defined as the fuel tank and tank-mounted
fuel pump/fuel gauge sender unit, the fuel
filter, the fuel injectors and the pressure
regulator in the injector rail, and the metal
pipes and flexible hoses of the fuel lines
between these components. All these contain
fuel, which will be under pressure while the
engine is running and/or while the ignition is
switched on.
2The pressure will remain for some time after
the ignition has been switched off, and must
be relieved before any of these components is
disturbed for servicing work.
3The simplest method is simply to
disconnect the fuel pump’s electrical supply
while the engine is running - either by
removing the fuel pump fuse (number 14), or
by lifting the red button on the fuel cut-off
switch (see Section 13) - and to allow the
engine to idle until it dies through lack of fuel
pressure. Turn the engine over once or twice
on the starter to ensure that all pressure is
released, then switch off the ignition; do not
forget to refit the fuse (or depress the redbutton, as appropriate) when work is
complete.
4The Ford method of depressurisation is to
use service tool 29-033 fitted to the fuel rail
pressure test/release fitting - a Schrader-type
valve with a blue plastic cap, located on the
union of the fuel feed line and the fuel rail - to
release the pressure, using a suitable
container and wads of rag to catch the spilt
fuel. Do notsimply depress the valve core to
release fuel pressure - droplets of fuel will
spray out, with a consequent risk of fire, and
of personal injury through fuel getting into
your eyes.
Warning: Either 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.
5Note that, once the fuel system has been
depressurised and drained (even partially), it
will take significantly longer to restart the
engine - perhaps several seconds of cranking
- before the system is refilled and pressure
restored.
Warning: The fuel system
pressure must be released before
any part of the system is
disturbed - see Section 2. Petrol
is extremely flammable, so take extra
precautions when you work on any part of
the fuel system. Don’t smoke, or allow
open flames or bare light bulbs, near the
work area. Don’t work in a garage where a
natural gas-type appliance (such as a
water heater or clothes dryer) with a pilot
light is present. If you spill any fuel on your
skin, rinse it off immediately with soap and
water. When you perform any kind of work
on the fuel system, wear safety glasses,
and have a Class B type fire extinguisher
on hand.
Disconnecting and connecting
quick-release couplings
1Quick-release couplings are employed at all
unions in the fuel feed and return lines.
2Before disconnecting any fuel system
component, relieve the residual pressure in
the 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.
3 Fuel lines and fittings-
general information
2 Fuel system - depressurisation
1 General information and
precautions
4•2 Fuel and exhaust systems
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3Release the protruding locking lugs on each
union, by squeezing them together and
carefully pulling the coupling apart. Use rag to
soak up any spilt fuel. Where the unions are
colour-coded, the pipes cannot be confused.
Where both unions are the same colour, note
carefully which pipe is connected to which,
and ensure that they are correctly
reconnected on refitting (see illustration).
4To reconnect one of these couplings, press
them together until the locking lugs snap into
their groove. Switch the ignition on and off
five times to pressurise the system, and check
for any sign of fuel leakage around the
disturbed coupling before attempting to start
the engine.
Checking
5Checking procedures for the fuel lines are
included in Chapter 1.
Component renewal
6If you must renew any damaged sections,
use original-equipment replacement hoses or
pipes, constructed from exactly the same
material as the section you are replacing. Do
not install substitutes constructed from
inferior or inappropriate material, or you could
cause a fuel leak or a fire.
7Before detaching or disconnecting any part
of the fuel system, note the routing of all
hoses and pipes, and the orientation of all
clamps and clips. Replacement sections must
be installed in exactly the same manner.8Before disconnecting any part of the fuel
system, be sure to relieve the fuel system
pressure (see Section 2), and equalise tank
pressure by removing the fuel filler cap. Also
disconnect the battery negative (earth) lead -
see Chapter 5, Section 1. Cover the fitting
being disconnected with a rag, to absorb any
fuel that may spray out.
Air cleaner assembly
1Disconnect the battery negative (earth) lead
- see Chapter 5, Section 1.
2Unclip the air mass meter from the air
cleaner cover (see Chapter 6).
3Disconnect the crankcase breather hose,
either from the air cleaner housing or from the
cylinder head cover union (see illustration).
4Remove the rubber retaining band (see
illustration). Withdraw the air cleaner
assembly, lifting it upwards out of its
grommets, and releasing it from the rubber
connector sleeve in the inner wing panel.
5Refitting is the reverse of the removal
procedure. Ensure that the housing pegs seat
correctly in their grommets, and that the
intake mouth is fully engaged inside the
connector sleeve (see illustration).
Air intake components
Note:Depending on the reason for removal,
these components can be removed either
individually, or as one assembly. For example,
unplugging the two electrical connectors and
disconnecting the vacuum hose (where fitted),
will allow the air cleaner assembly cover to be
removed with the air mass meter, the
resonator and the plenum chamber.
Air mass meter
6Refer to Section 4 of Chapter 6.
Resonator (engine compartment)
7Unbolt the resonator support bracket from
the engine compartment front crossmember.
Slacken the two clamp screws securing the
resonator to the air mass meter and plenum
chamber hoses. Swing the resonator clear of
the thermostat housing, and unplug the intake
air temperature sensor’s electrical connector
(see illustration). Withdraw the resonator.
8Refitting is the reverse of the removal
procedure.
Plenum chamber
9Prising out the rubber plugs covering them,
undo the chamber’s fasteners (see
illustration). Slacken the clamp screw
securing the chamber to the resonator hose.
10Lift the chamber and (where fitted)
disconnect the vacuum hose from its
underside. Withdraw the chamber - note the
two rubber spacers (one on each throttle
4 Air cleaner assembly and air
intake components -
removal and refitting
Fuel and exhaust systems 4•3
4
4.5 Ensure air filter housing intake mouth
is fully engaged inside connector sleeve4.7 Unplugging intake air temperature
sensor’s electrical connector4.9 Plenum chamber fasteners (arrowed) -
four shown here, some vehicles may only
have three
3.3 Disconnect fuel line quick-release
couplings by squeezing together protruding
locking lugs and pulling coupling apart4.3 Disconnecting the crankcase breather
hose from the cylinder head union4.4 Remove rubber retaining band to
withdraw air cleaner assembly
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(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.
6Detach 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
this Chapter’s Specifications. If the pressure
increase is not as specified, check the
vacuum hose and pressure regulator.
7Reconnect the regulator vacuum hose, and
switch off the engine. Verify that the fuel
pressure stays at the specified level for five
minutes after the engine is turned off.
8Carefully disconnect the fuel pressure
gauge. Be sure to cover the fitting with a rag
before slackening it. Mop up any spilt petrol.
9Run the engine, and check that there are no
fuel leaks.
Warning: Petrol is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system. Don’t smoke,
or allow open flames or bare light bulbs,
near the work area. Don’t work in a garage
where a natural gas-type appliance (such
as a water heater or clothes dryer) with a
pilot light is present. If you spill any fuel on
your skin, rinse it off immediately with
soap and water. When you perform any
kind of work on the fuel system, wear
safety glasses, and have a Class B type
fire extinguisher on hand.
Note: Ford specify the use of their service tool
23-038 (a large box spanner with projecting teeth
to engage the fuel pump/sender unit retaining
ring’s slots) for this task. While alternatives are
possible, as shown below, in view of the difficulty
experienced in removing and refitting the
pump/sender unit, owners are strongly advised
to obtain this tool before starting work. The help
of an assistant will be required.
1Relieve 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.
2Disconnect the battery negative (earth) lead
- see Chapter 5, Section 1.
3Unbolt or fold forwards (as appropriate) the
rear seat base cushion (see Chapter 11).
Withdraw from the vehicle’s floor the grommet
covering the fuel pump/sender unit. Wash off
any dirt from the tank’s top surface, and dry it;
use a vacuum cleaner to clean the immediate
surroundings of the vehicle’s interior, to
reduce the risk of introducing water, dirt and
dust into the tank while it is open.
4Unplug the fuel pump/sender unit’s
electrical connector (see illustration).
5To disconnect the fuel feed and return
pipes from the unit, release each pipe’s
coupling, by squeezing together the
protruding locking lugs on each union and
carefully pulling the coupling apart. Use rag to
soak up any spilt fuel. Where the couplings
are difficult to separate, use a pair of pliers
and a block of wood as shown, to lever the
pipe out of the union. Considerable force maybe required, but be as careful as possible to
avoid damaging any of the components (see
illustration).
6Release the fuel pump/sender unit’s
retaining ring by turning it anti-clockwise. As
noted above, Ford recommend the use of
service tool 23-038. For those without access
to such equipment, a hammer and drift, or a
pair of slip-jointed pliers, will serve as an
adequate substitute - at least for removal (see
illustration).
7Withdraw the fuel pump/fuel gauge sender
unit, taking care not to bend the float arm. The
float arm is mounted on a spring-loaded
extension, to hold it closely against the
bottom of the tank. Note the sealing ring; this
must be renewed whenever it is disturbed
(see illustrations).
8On refitting, use a new sealing ring, and
ensure that the gauze filter over the base of
the pump pick-up is clean.
9Align the pump/sender unit with the tank
opening, and refit it, ensuring that the float
arm is not bent. Insert the unit so that the float
arm slides correctly up the extension, until the
unit’s top mounting plate can be aligned with
the tank opening and pressed onto the sealing
ring. This may require a considerable amount
of pressure; if so, be careful to avoid
damaging any of the components. The Ford
service tool provides the best way of holding
9 Fuel pump/fuel gauge sender
unit- removal and refitting
4•6 Fuel and exhaust systems
9.4 Unplugging the fuel pump/fuel gauge
sender unit electrical connector (arrowed)9.5 If fuel couplings are difficult to release,
use pliers and a block of wood as shown
to prise pipe end out of union - be careful
not to damage pipes or unions9.6 Fuel pump/fuel gauge sender unit’s
retaining ring can be released using
ordinary tools as shown. Correct service
tool will probably be required on refitting
9.7A Removing fuel pump/fuel gauge
sender unit - take care not to bend float
arm, and note how it is fitted on spring-
loaded extension9.7B Fuel pump/fuel gauge sender unit’s
sealing ring must be renewed whenever it
is disturbed
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(b) On Estate models, slacken the clamp
immediately above the rear anti-roll bar,
and work the hose off the filler neck stub
(see illustration).
8Unscrew the six retaining nuts, and
withdraw the exhaust system’s rear heat
shield from the underbody (see illustration).
9Support the tank with a trolley jack or
similar. Place a sturdy plank between the
support and the tank, to protect the tank.
10Unscrew the bolt at the front of each
retaining strap, and pivot them down until
they are hanging out of the way. Note the
earth lead under the left-hand strap’s bolt -
clean the mating surfaces before the tank is
refitted, so that clean, metal-to-metal contact
is ensured.
11Lower the tank enough to unclip the fuel
return pipe (coded red) from its top surface,
then disconnect the charcoal canister’s
vapour hose from the union at the top rear of
the tank (see illustration). If you have any
doubts, clearly label the fuel lines and hoses,
and their respective unions. Plug the hoses, to
prevent leakage and contamination of the fuel
system.
12Remove the tank from the vehicle,
releasing it from the filler neck stub. While the
tank is removed, unhook the retaining straps
(twist them through 90° to do so), and check
that they and their locations in the underbody
are in good condition.
13With the fuel tank removed, the filler neck
can be withdrawn. It is secured by a single
screw in the filler opening, and by two bolts to
the underbody.
14Refitting is the reverse of the removal
procedure.
Warning: Petrol is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system. Don’t
smoke, or allow open flames or bare light
bulbs, near the work area. Don’t work in a
garage where a natural gas-type appliance(such as a water heater or clothes dryer)
with a pilot light is present. If you spill any
fuel on your skin, rinse it off immediately
with soap and water. When you perform
any kind of work on the fuel system, wear
safety glasses, and have a Class B type
fire extinguisher on hand.
1Any repairs to the fuel tank or filler neck
should be carried out by a professional who
has experience in this critical and potentially-
dangerous work. Even after cleaning and
flushing of the fuel system, explosive fumes
can remain and ignite during repair of the
tank.
2If the fuel tank is removed from the vehicle,
it should not be placed in an area where
sparks or open flames could ignite the fumes
coming out of the tank. Be especially careful
inside garages where a natural gas-type
appliance is located, because the pilot light
could cause an explosion.
Warning: The fuel system
pressure must be released before
any part of the system is
disturbed - see Section 2. Petrol
is extremely flammable, so take extra
precautions when you work on any part of
the fuel system. Don’t smoke, or allow
open flames or bare light bulbs, near the
work area. Don’t work in a garage where a
natural gas-type appliance (such as a
water heater or clothes dryer) with a pilot
light is present. If you spill any fuel on your
skin, rinse it off immediately with soap and
water. When you perform any kind of work
on the fuel system, wear safety glasses,
and have a Class B type fire extinguisher
on hand.
Note: Refer to illustrations 10.4 and 10.11 for
details.
1Remove the fuel tank (see Section 10).
2Prise the two valves out of the tank, and
remove the anti-trickle fill valve from its
mounting. Take care not to damage the valves
or the tank. Prise out the rubber seals fromthe tank openings, and renew then if they are
worn, distorted, or if either has been leaking.
3If either valve is thought to be faulty, seek
the advice of a Ford dealer as to whether they
can be renewed individually. If not, the
complete valve and pipe assembly must be
renewed.
4Refitting is the reverse of the removal
procedure. Ensure that both roll-over valves
are pressed securely into their seals, so that
there can be no fuel leaks.
1Disconnect the battery negative (earth) lead
- see Chapter 5, Section 1.
2Remove the trim panel from the left-hand
footwell.
3Peel back the sound-insulating material
from the switch, and undo its two retaining
screws (see illustration).
4Unplug the switch electrical connector, and
withdraw the switch.
5Refitting is the reverse of the removal
procedure. Ensure that the switch is reset by
depressing its red button.
These models are equipped with a
Sequential Electronically-controlled Fuel
Injection (SEFI) system. The system is
composed of three basic sub-systems: fuel
system, air induction system and electronic
control system. Note:Refer to illustrations
2.1A and 2.1B of Chapter 6 for further
information on the components of the system.
Fuel system
An electric fuel pump located inside the fuel
tank supplies fuel under pressure to the fuel
rail, which distributes fuel evenly to all
injectors. A filter between the fuel pump and
the fuel rail protects the components of the
system. A pressure regulator controls the
system pressure in relation to inlet tract
depression. From the fuel rail, fuel is injected
14 Fuel injection system/engine
management system - general
information
13 Fuel cut-off switch -
removal and refitting
12 Roll-over valves -
removal and refitting
11 Fuel tank cleaning and repair -
general information
4•8 Fuel and exhaust systems
10.8 Exhaust system must be lowered and
heat shield removed to enable fuel tank
removal - arrows show location of
retaining strap front bolts10.11 Lower fuel tank - do not distort filler
neck stub (A) - and unclip (red-coded) fuel
return pipe (B), then disconnect charcoal
canister’s vapour hose (C)13.3 Fuel cut-off switch retaining screws
(arrowed)
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into the inlet ports, just above the inlet valves,
by four fuel injectors. The system also
includes features such as the flushing of fresh
(ie, cold) fuel around each injector on start-up,
thus improving hot starts.
The amount of fuel supplied by the injectors
is precisely controlled by an Electronic
Control Unit (ECU). The ECU uses the signals
derived from the engine speed/crankshaft
position sensor and the camshaft position
sensor, to trigger each injector separately in
cylinder firing order (sequential injection), with
benefits in terms of better fuel economy and
lower exhaust emissions.
Air induction system
The air system consists of an air filter
housing, an air mass meter, an intake
resonator and plenum chamber, and a throttle
housing. The air mass meter is an information-
gathering device for the ECU; it uses a “hot-
wire” system to send the ECU a constantly-
varying (analogue) voltage signal
corresponding to the volume of air passing
into the engine. Another sensor in the air mass
meter measures intake air temperature. The
ECU uses these signals to calculate the mass
of air entering the engine.
The throttle valve inside the throttle housing
is controlled by the driver, through the
accelerator pedal. As the valve opens, the
amount of air that can pass through the
system increases. The throttle potentiometer
opens further, the air mass meter’s signal
alters, and the ECU opens each injector for a
longer duration, to increase the amount of fuel
delivered to the inlet ports.
Electronic control system
The ECU controls the fuel injection system,
as well as the other sub-systems which make
up the entire engine management system. It
receives signals from a number of information
sensors, which monitor such variables as
intake air mass and temperature, coolant
temperature, engine speed and position,
acceleration/deceleration, and exhaust gas
oxygen content. These signals help the ECU
determine the injection duration necessary for
the optimum air/fuel ratio. These sensors and
associated ECU-controlled relays are located
throughout the engine compartment. For
further information regarding the ECU and its
control of the engine management system,
see Chapter 6.
Idle speed and mixture
adjustment - general
Both the idle speed and mixture are under
the control of the ECU, and cannot be
adjusted. Not only can they not be adjusted,
they cannot even be checked, except with the
use of special diagnostic equipment (see
Chapter 6) - this makes it a task for a Ford
dealer service department. Do notattempt to
“adjust” these settings in any way without
such equipment.
If the idle speed and mixture are thought tobe incorrect, take the vehicle to a Ford dealer
for the complete system to be tested.
On models equipped with a heated
windscreen, an idle-increase solenoid valve is
fitted, which raises the idle speed to
compensate for the increased load on the
engine when the heated windscreen is
switched on. When the valve is open, air from
the plenum chamber bypasses the throttle
housing and idle speed control valve, passing
directly into the inlet manifold through the
union on its left-hand end. The system is
active only for the four minutes that the
heated windscreen circuit is live, and is
supplementary to the main (ECU-controlled)
idle speed regulation.
Warning: Petrol is extremely
flammable, so extra precautions
must be taken when working on
any part of the fuel system. Do
not smoke, or allow open flames or bare
light bulbs, near the work area. Don’t work
in a garage if a natural gas-type appliance
with a pilot light is present. While
performing any work on the fuel system,
wear safety glasses, and have a dry
chemical (Class B) fire extinguisher on
hand. If you spill any fuel on your skin,
rinse it off immediately with soap and
water.
Note: This is an initial check of the fuel delivery
and air induction sub-systems of the engine
management system, to be carried out in
conjunction with the operational check of the
fuel pump (see Section 8), and as part of the
preliminary checks of the complete engine
management system (see Section 3 of
Chapter 6).
1Check the earth wire connections for
tightness. Check all wiring and electrical
connectors that are related to the system.
Loose electrical connectors and poor earths
can cause many problems that resemble
more serious malfunctions.
2Check to see that the battery is fully-
charged. The ECU and sensors depend on an
accurate supply voltage to properly meter the
fuel.
3Check the air filter element - a dirty or
partially-blocked filter will severely impede
performance and economy (see Chapter 1).
4If a blown fuse is found, renew it and see if
it blows again. If it does, search for a short-
circuited wire in the harness related to the
system (see Chapter 6).
5Check the air intake duct from the intake to
the inlet manifold for leaks, which will result in
an excessively-lean mixture. Also check the
condition of the vacuum hoses connected to
the inlet manifold.
6Remove the plenum chamber from the
throttle housing. Check the throttle valve for
dirt, carbon or other residue build-up. If it’sdirty, seek the advice of a Ford dealer - since
the electronic control system is designed to
compensate for factors such as the build-up
of dirt in the throttle housing, it may well be
best to leave it dirty, unless the deposits are
extensive. Note: A warning label on the
housing states specifically that the housing
bore and the throttle valve have a special
coating, and must not be cleaned using
carburettor cleaner, as this may damage it.
7With the engine running, place a
screwdriver or a stethoscope against each
injector, one at a time. Listen through the
screwdriver handle or stethoscope for a
clicking sound, indicating operation.
8If an injector isn’t operating (or sounds
different from the others), turn off the engine,
and unplug the electrical connector from the
injector. Check the resistance across the
terminals of the injector, and compare your
reading with the resistance value listed in this
Chapter’s Specifications. If the resistance
isn’t as specified, renew the injector.
9A rough idle, diminished performance
and/or increased fuel consumption could also
be caused by clogged or fouled fuel injectors.
Fuel additives that can sometimes clean
fouled injectors are available at car accessory
shops.
10The remainder of the system checks
should be left to a dealer service department
or other qualified repair specialist, as there is
a chance that the ECU may be damaged if
tests are not performed properly.
Warning: The fuel system
pressure must be released before
any part of the system is
disturbed - see Section 2. Petrol
is extremely flammable, so take extra
precautions when you work on any part of
the fuel system. Don’t smoke, or allow
open flames or bare light bulbs, near the
work area. Don’t work in a garage where a
natural gas-type appliance (such as a
water heater or clothes dryer) with a pilot
light is present. If you spill any fuel on your
skin, rinse it off immediately with soap and
water. When you perform any kind of work
on the fuel system, wear safety glasses,
and have a Class B type fire extinguisher
on hand.
Throttle housing
Check
1Remove the plenum chamber (see Sec-
tion 4), and verify that the throttle linkage
operates smoothly.
2If the housing bore and valve are dirty
enough for you to think that this might be the
cause of a fault, seek the advice of a Ford
dealer. Do notclean the housing (see the
notes in the checking procedure given in
Section 15).
16 Fuel system components-
check and renewal
15 Fuel injection system/engine
management system - check
Fuel and exhaust systems 4•9
4
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5Undo the sensor’s retaining screw and
withdraw the sensor. The sensor’s bracket
cannot be unbolted from the cylinder
block/crankcase unless the transmission and
flywheel/driveplate have been removed (see
Chapter 2).
6Refitting is the reverse of the removal
procedure.
General information
The charging system includes the
alternator, an internal voltage regulator, a no-
charge (or “ignition”) warning light, the
battery, and the wiring between all the
components. The charging system supplies
electrical power for the ignition system, the
lights, the radio, etc. The alternator is driven
by the auxiliary drivebelt at the front (right-
hand end) of the engine.
The purpose of the voltage regulator is to
limit the alternator’s voltage to a preset value.
This prevents power surges, circuit overloads,
etc., during peak voltage output.
The charging system doesn’t ordinarily
require periodic maintenance. However, the
drivebelt, battery and wires and connections
should be inspected at the intervals outlined
in Chapter 1.
The dashboard warning light should come
on when the ignition key is turned to positions
“II” or “III”, then should go off immediately the
engine starts. If it remains on, or if it comes on
while the engine is running, there is a
malfunction in the charging system (see
Section 11). If the light does not come on
when the ignition key is turned, and the bulb is
sound (see Chapter 12), there is a fault in the
alternator.
Precautions
Be very careful when making electrical
circuit connections to a vehicle equipped with
an alternator, and note the following:
(a) When reconnecting wires to the alternator
from the battery, be sure to note the
polarity.
(b) Before using arc-welding equipment to
repair any part of the vehicle, disconnect
the wires from the alternator and the
battery terminals.
(c) Never start the engine with a battery
charger connected.
(d) Always disconnect both battery leads
before using a battery charger.
(e) The alternator is driven by an engine
drivebelt which could cause serious injury
if your hand, hair or clothes become
entangled in it with the engine running.
(f) Because the alternator is connected
directly to the battery, it could arc or
cause a fire if overloaded or shorted-out.
(g) Wrap a plastic bag over the alternator,
and secure it with rubber bands, beforesteam-cleaning or pressure-washing the
engine.
(h) Never disconnect the alternator terminals
while the engine is running.
1If a malfunction occurs in the charging
circuit, don’t automatically assume that the
alternator is causing the problem. First check
the following items:
(a) Check the tension and condition of the
auxiliary drivebelt - renew it if it is worn or
deteriorated (see Chapter 1).
(b) Ensure the alternator mounting bolts and
nuts are tight.
(c) Inspect the alternator wiring harness and
the electrical connections at the
alternator; they must be in good
condition, and tight.
(d) Check the large main fuses in the engine
compartment (see Chapter 12). If any is
blown, determine the cause, repair the
circuit and renew the fuse (the vehicle
won’t start and/or the accessories won’t
work if the fuse is blown).
(e) Start the engine and check the alternator
for abnormal noises - for example, a
shrieking or squealing sound may indicate
a badly-worn bearing or brush.
(f) Make sure that the battery is fully-charged
- one bad cell in a battery can cause
overcharging by the alternator.
(g) Disconnect the battery leads (negative
first, then positive). Inspect the battery
posts and the lead clamps for corrosion.
Clean them thoroughly if necessary (see
Section 3 and Chapter 1). Reconnect the
lead to the negative terminal.
(h) With the ignition and all accessories
switched off, insert a test light between
the battery negative post and the
disconnected negative lead clamp:
(1) If the test light does not come on, re-
attach the clamp and proceed to the next
step.
(2) If the test light comes on, there is a short
in the electrical system of the vehicle. The
short must be repaired before the
charging system can be checked.
(3) To find the short, disconnect the
alternator wiring harness:
(a) If the light goes out, the alternator is
at fault.
(b) If the light stays on, remove each fuse
until it goes out - this will tell you
which component is short-circuited.
2Using a voltmeter, check the battery
voltage with the engine off. It should be
approximately 12 volts.
3Start the engine and check the battery
voltage again. Increase engine speed until the
voltmeter reading remains steady; it should
now be approximately 13.5 to 14.6 volts.
4Switch on as many electrical accessories
(eg the headlights, heated rear window andheater blower) as possible, and check that the
alternator maintains the regulated voltage at
around 13 to 14 volts. The voltage may drop
and then come back up; it may also be
necessary to increase engine speed slightly,
even if the charging system is working
properly.
5If the voltage reading is greater than the
specified charging voltage, renew the voltage
regulator (see Section 13).
6If the voltmeter reading is less than that
specified, the fault may be due to worn
brushes, weak brush springs, a faulty voltage
regulator, a faulty diode, a severed phase
winding, or worn or damaged slip rings. The
brushes and slip rings may be checked (see
Section 13), but if the fault persists, the
alternator should be renewed or taken to an
auto-electrician for testing and repair.
1Disconnect the battery negative (earth) lead
- see Section 1.
2Remove the plenum chamber (see Chap-
ter 4).
3Unscrew the nuts to disconnect the wiring
from the alternator (see illustration). If
additional working clearance is required, undo
the right-hand of the three screws securing
the wiring “rail” to the rear of the inlet
manifold.
4Jack up and support the front right-hand
corner of the vehicle. Remove the auxiliary
drivebelt and the engine oil filter - place a wad
of rag to soak up the spilled oil (see Chap-
ter 1). Rather than refit a used filter, you are
advised to drain the engine oil, and then to fit
a new filter and refill the engine with clean oil
on reassembly. Where an engine oil cooler is
fitted, it may prove necessary to remove this
as well, to provide the clearance necessary to
remove the alternator (see Chapter 2, Part A).
5Unscrew the two bolts securing the power
steering system pipes to the right-hand side
of the front suspension subframe. With the
front wheels in the straight-ahead position,
disconnect the right-hand track rod end from
the steering knuckle (see Chapter 10).
6Remove the mounting bolts and nuts (one
12 Alternator-
removal and refitting
11 Charging system- testing
10 Charging system - general
information and precautions
Engine electrical systems 5•5
5
12.3 Disconnecting alternator wiring
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Removal
8With the wheel and caliper removed,
remove the wheel nuts which were
temporarily refitted in paragraph 3.
9Mark the disc in relation to the hub, if it is to
be refitted.
10Remove the two special washers (where
fitted), and withdraw the disc over the wheel
studs (see illustrations).
Refitting
11Make sure that the disc and hub mating
surfaces are clean, then locate the disc on the
wheel studs. Align the previously-made marks
if the original disc is being refitted.
12Refit the two special washers, where
fitted.
13Refit the brake caliper and carrier bracket
with reference to Section 3.
14Refit the wheel, and lower the vehicle to
the ground.
15Test the brakes carefully before returning
the vehicle to normal service.
Note:To prevent uneven braking, BOTH rear
brake drums should be renewed at the same
time.
Removal
1Chock the front wheels, release the
handbrake and engage 1st gear (or “P”).Loosen the relevant wheel nuts, jack up the
rear of the vehicle and support it on axle
stands. Remove the wheel.
2Remove the two special clips (where fitted),
and withdraw the brake drum over the wheel
studs. If the drum will not pass over the
shoes, it is possible to release the automatic
adjuster mechanism by prising out the small
rubber grommet near the centre of the
backplate, and inserting a screwdriver
through the small hole. The self-adjusting
ratchet can then be rotated, so that the brake
shoes move to their lowest setting (see
illustrations). Refit the rubber grommet
before proceeding.
3With the brake drum removed, clean the
dust from the drum, brake shoes, wheel
cylinder and backplate, using brake cleaner or
methylated spirit. Take care not to inhale the
dust, as it may contain asbestos.
Inspection
4Clean the inside surfaces of the brake
drum, then examine the internal friction
surface for signs of scoring or cracks. If it is
cracked, deeply scored, or has worn to a
diameter greater than the maximum given in
the Specifications, then it should be renewed,
together with the drum on the other side.
5Regrinding of the brake drum is not
recommended.
Refitting
6Locate the brake drum over the wheel
studs, and (where fitted) refit the special clips.Make sure that the drum contacts the hub
flange.
7Refit the wheel, then check the remaining
rear drum.
8Lower the vehicle to the ground, and
tighten the wheel nuts to the specified torque.
Depress the brake pedal several times, in
order to operate the self-adjusting mechanism
and set the shoes at their normal operating
position.
9Test the brakes carefully before returning
the vehicle to normal service.
Warning: Drum brake shoes must
be renewed on both rear wheels
at the same time - never renew
the shoes on only one wheel, as
uneven braking may result. Also, the dust
created by wear of the shoes may contain
asbestos, which is a health hazard. Never
blow it out with compressed air, and don’t
inhale any of it. An approved filtering mask
should be worn when working on the
brakes. DO NOT use petroleum-based
solvents to clean brake parts; use brake
cleaner or methylated spirit only.
1Remove the rear brake drums as described
in Section 5. Work on one brake assembly at a
time, using the assembled brake for reference
if necessary.
2Follow the accompanying illustrations for
the brake shoe renewal procedure (see
illustrations 6.2A to 6.2O). Be sure to stay in
order, and read the caption under each
illustration.
3If the wheel cylinder shows signs of fluid
leakage, or if there is any reason to suspect it
of being defective, inspect it now, as
described in the next Section.
4Fit the new brake shoes using a reversal of
the removal procedure, but set the eccentric
cam at its lowest position before assembling it
to the trailing shoe.
5Before refitting the brake drum, it should be
checked as described in Section 5.
6 Rear brake shoes - renewal
5 Rear brake drum - removal,
inspection and refitting
9•6 Braking system
4.10A Remove the special washers . . .4.10B . . . and withdraw the disc
5.2A Releasing the automatic adjuster
mechanism with a screwdriver inserted
through the small hole in the backplate5.2B Removing a rear brake drum
6.2A Note the fitted position of the springs
and the adjuster strut, then clean the
components with brake cleaner, and allow
to dry. Position a tray beneath the
backplate, to catch the fluid and residue
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Chapter 6 Emissions control systems
Catalytic converter - general information, checking
and component renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Diagnosis system - general information . . . . . . . . . . . . . . . . . . . . . . 3
Electronic control system - description and precautions . . . . . . . . . 2
Engine compartment wiring check . . . . . . . . . . . . . . . See Chapter 1
EVAPorative emissions control (EVAP) system - general
information, checking and component renewal . . . . . . . . . . . . . . 5
Exhaust Gas Recirculation (EGR) system - general
information, checking and component renewal . . . . . . . . . . . . . . 6
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Information sensors - general information, testing,
removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Positive Crankcase Ventilation (PCV) system - general
information, checking and component renewal . . . . . . . . . . . . . . 8
Positive Crankcase Ventilation (PCV) system check
and filter cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Pulse-air system - general information, checking
and component renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Underbonnet hose check . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Crankshaft speed/position sensor
Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 to 450 ohms
Camshaft position sensor
Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 to 900 ohms
Intake air temperature sensor
Resistance:
At -40°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 860 to 900 k ohms
At 20°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 to 40 k ohms
At 100°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9 to 2.5 k ohms
At 120°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 to 1.3 k ohms
Throttle potentiometer
Resistance - see text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 to 6000 ohms
Power steering pressure switch
Operating pressure - green switch body:
Contacts open - infinite resistance . . . . . . . . . . . . . . . . . . . . . . . . . . 31.5 ± 3.5 bars
Contacts close - 0 to 2.5 ohms resistance . . . . . . . . . . . . . . . . . . . . Between 13.5 and 24.0 bars
Charcoal canister-purge solenoid valve
Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 to 120 ohms
Pulse-air solenoid valve
Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 to 120 ohms
Torque wrench settingsNm lbf ft
Camshaft position sensor screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 to 23 13 to 17
Intake air temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 17
Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 44
Exhaust Gas Recirculation (EGR) system components:
Valve-to-inlet manifold bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6
Pipe-to-ignition coil screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Pulse-air system components:
Filter housing mounting bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 35
Piping-to-exhaust manifold sleeve nuts . . . . . . . . . . . . . . . . . . . . . . . 32 24
6•1
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,suitable
for competent DIY
mechanicDifficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
Specifications Contents
6
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