Ford Fiesta (1989-1995). Instruction - part 35

Fuel pump/fuel pressure -
checking

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

Fuel pump operation check

1 Switch on the ignition, and listen for the fuel
pump (the sound of an electric motor running,
audible from beneath the rear seats).
Assuming there is sufficient fuel in the tank,
the pump should start and run for
approximately one or two seconds, then stop,
each time the ignition is switched on. Note: If
the pump runs continuously all the time the
ignition is switched on, the electronic control
system is running in the backup (or “limp-
home”) mode referred to by Ford as “Limited
Operation Strategy” (LOS). This almost
certainly indicates a fault in the EEC IV module
itself, and the vehicle should therefore be
taken to a Ford dealer for a full test of the
complete system, using the correct diagnostic
equipment; do not waste time or risk
damaging the components by trying to test
the system without such facilities.
2 Listen for fuel return noises from the fuel
pressure regulator. It should be possible to
feel the fuel pulsing in the regulator and in the
feed hose from the fuel filter.
3 If the pump does not run at all, check the
fuse, relay and wiring (see Chapter 12). Check
also that the fuel cut-off switch has not been
activated and if so, reset it.

Fuel pressure check

4 A fuel pressure gauge will be required for
this check and should be connected in the
fuel line between the fuel filter and the fuel rail,
in accordance with the gauge maker’s
instructions. 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.

Fuel tank - removal,
inspection and refitting

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.

Fuel pump/fuel gauge
sender unit - removal and
refitting

Refer to Part B, Section 9.

10 Fuel tank ventilation tube -

removal and refitting

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

Refer to Part A, Section 11.

12 Fuel cut-off switch -

removal and refitting

Refer to Part B, Section 12.

13 Fuel injection system -

checking

Refer to Part B, Section 13

14 Fuel injection system

components - removal and
refitting

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 Remake

and gasket. Discard the gasket - this must be
renewed whenever it is disturbed.
7 Refit 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 flange

14.17a Unscrewing fuel rail mounting bolts

(arrowed)

14.24 Fuel pressure regulator vacuum

hose (A) and retaining bolts (B)

14.20 Fit new nose seals (arrowed) before

refitting the fuel rail

1595Ford Fiesta Remake

25 Refitting is the reverse of the removal
procedure, noting the following points:

a) Renew the regulator sealing O-ring

whenever the regulator is disturbed.
Lubricate the new O-ring with clean
engine oil on installation.

b) Locate the regulator carefully in the fuel

rail recess, and tighten the bolts securely.

c) On completion, switch the ignition on and

Idle speed control valve

26 Disconnect the battery negative (earth)
lead (refer to Chapter 5A, Section 1).
27 Disconnect the valve’s wiring multi-plug
(see illustration).
28 Unscrew the three retaining bolts, and
withdraw the valve from the inlet manifold.
29 Refitting is the reverse of the removal
procedure, noting the following points:

a) Clean the mating surfaces carefully, and

always fit a new gasket whenever the
valve is disturbed.

b) Once the wiring and battery are

reconnected, start the engine and allow it
to idle. When it has reached normal
operating temperature, check that the idle
speed is stable, and that no induction (air)
leaks are evident. Switch on all electrical

loads (headlights, heated rear window,
etc), and check that the idle speed is still
satisfactory.

Mass air flow sensor

30 Releasing its wire clip, unplug the
electrical connector from the sensor (see
illustration 4.2a).
31 Release the two clips and detach the
sensor from the air cleaner cover (see
illustrations 4.2b and 4.2c).
32 Slacken the clamp securing the sensor to
the air inlet hose, and withdraw the sensor.
33 Refitting is the reverse of the removal
procedure. Ensure that the sensor and air
cleaner cover are seated correctly and
securely fastened, so that there are no air
leaks.

EEC IV engine management
module

Note: The module is fragile. Take care not to
drop it, or subject it to any other kind of
impact. Do not subject it to extremes of
temperature, or allow it to get wet. Refer to
Part B, Section 14 for illustrations of the
following procedure.
34 Disconnect the battery negative (earth)
lead (refer to Chapter 5A, Section 1).
35 Remove the cooling system expansion
tank as described in Chapter 3, for access to
the module multi-plug.
36 Unscrew and remove the two nuts
securing the module cover in the engine
compartment, then carefully draw the cover
away from its location. Unscrew the module
multi-plug retaining bolt and disconnect
the multi-plug from the module.
37 The aid of an assistant will be required at
this stage, to support and withdraw the
module from inside the passenger
compartment as its mounting bracket retaining
tags are compressed and released from the
engine compartment. Do not allow the module
to drop into the passenger compartment as
irreparable damage is likely to result. The
module may be separated from its mounting
bracket by undoing the securing bolts.
38 Refitting is a reversal of the removal
procedure, ensuring that the module
mounting bracket retaining tags are felt to

snap into position. Refit the expansion tank as
described in Chapter 3 on completion.

Crankshaft position sensor

39 Refer to Chapter 5B.

Camshaft position sensor

40 Where applicable, release the fuel feed
and return hoses from their clip. On PTE
engines, detach the adjacent engine breather
hose.
41 Releasing its wire clip, unplug the
sensor’s wiring multi-plug. Remove the
retaining screw, and withdraw the sensor from
the cylinder head; be prepared for slight oil
loss (see illustration).
42 Refitting is the reverse of the removal
procedure, noting the following points:

a) Apply petroleum jelly or clean engine oil

to the sensor’s sealing O-ring.

b) Locate the sensor fully in the cylinder

head, and wipe off any surplus lubricant
before securing it.

c) Tighten the screw to the specified torque

wrench setting.

Coolant temperature sensor

43 Refer to Chapter 3.

Inlet air temperature sensor

44 Releasing its clip, unplug the sensor’s
electrical connector, then unscrew the sensor
from the inlet manifold (see illustration).
45 Refitting is the reverse of the removal
procedure.

Throttle position sensor

46 Releasing its wire clip, unplug the
sensor’s wiring multi-plug. Remove the
retaining screws, and withdraw the unit from
the throttle housing (see illustration). Do not
force the sensor’s centre to rotate past its
normal operating sweep; the unit will be
seriously damaged.
47 Refitting is the reverse of the removal
procedure, noting the following points:

a) Ensure that the sensor is correctly

orientated, by locating its centre on the D-
shaped throttle shaft (throttle closed), and
aligning the sensor body so that the bolts
pass easily into the throttle housing.

4D•6 Fuel system - sequential electronic fuel injection engines

14.46 Throttle position sensor mounting

screws (arrowed)

14.44 Removing the intake air temperature

sensor from the rear of the inlet manifold

(Zetec engine shown)

14.41 Disconnecting the camshaft position

sensor wiring multi-plug (Zetec engine

shown)

14.27 Idle speed control valve wiring

multi-plug (A) and visible mounting

bolts (B)

1595Ford Fiesta Remake

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

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

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 Bolts

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