Peugeot 205 (954 cc, 1124 cc, 1360 cc, 1580 cc & 1905 cc). Manual - part 16

4B•8

Notes

4C

Chapter 4  Part C:
Fuel system - multi-point fuel injection engines

General

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

Rear-mounted fuel tank, electric fuel pump, multi-point fuel injection
system

System application:

XU5J, XU5JA, XU5JA/K, XU51C/K, XU9JA, XU9JA/K  . . . . . . . . . . . .

Bosch LE2-Jetronic

XU9J1/Z, XU9J1/L  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bosch LU2-Jetronic

XU9JA/Z, XU9JA/L  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bosch Motronic M1.3

Fuel system data

Regulated fuel pressure  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.9 to 3.1 bar

Fuel pump delivery  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

540 cc/15 sec

Idling speed  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

900 ± 50 rpm

Idle mixture CO content*  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.0 to 2.0 %

*Adjustable on LE2-Jetronic system only - controlled by ECU on all other systems

Recommended fuel

Minimum octane rating (see text Section 8)  . . . . . . . . . . . . . . . . . . . . . .

95 RON unleaded or 97/98 RON unleaded*

* Note: The XU9JA engine should not be operated on 95 RON unleaded petrol

Air cleaner assembly - removal and refitting  . . . . . . . . . . . . . . . . . . . 2
Air cleaner element renewal  . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Fuel gauge sender unit - removal and refitting  . . . . . . . . . . . . . . . . . 6
Fuel injection system - checks and adjustment  . . . . . . . . . . . . . . . . 10
Fuel injection system components - removal and refitting  . . . . . . . . 11
Fuel injection systems - general information  . . . . . . . . . . . . . . . . . . . 9
Fuel pump - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Fuel system - depressurisation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Fuel tank - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
General fuel system checks  . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
General information and precautions  . . . . . . . . . . . . . . . . . . . . . . . . 1
Idle speed and mixture adjustment  . . . . . . . . . . . . . . . . .See Chapter 1
Inlet manifold - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . 12
Throttle cable - removal, refitting and adjustment . . . . . . . . . . . . . . . 3
Underbody and fuel/brake line check  . . . . . . . . . . . . . . .See Chapter 1
Underbonnet check for fluid leaks and hose condition . .See Chapter 1
Unleaded petrol - general information and usage  . . . . . . . . . . . . . . . 8

4C•1

Specifications

Contents

Easy, suitable for
novice with little
experience

Fairly easy, suitable
for beginner with
some experience

Fairly difficult,
suitable for competent
DIY mechanic

Difficult, suitable for
experienced  DIY
mechanic

Very difficult,
suitable for expert DIY
or  professional

Degrees of difficulty

5

4

3

2

1

1

General information and
precautions

General information

The fuel supply system consists of a fuel

tank (which is mounted under the rear of the
car, with an electric fuel pump immersed in it),
a fuel filter, fuel feed and return lines. The fuel
pump supplies fuel to the fuel rail, which acts
as a reservoir for the four fuel injectors which
inject fuel into the inlet tracts. The fuel filter
incorporated in the feed line from the pump to
the fuel rail ensures that the fuel supplied to
the injectors is clean.

Refer to Section 9 for further information on

the operation of each fuel injection system.

Precautions

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

or allow any naked flames or uncovered
light bulbs near the work area. Note that
gas powered domestic appliances with pilot
flames, such as heaters, boilers and tumble
dryers, also present a fire hazard - bear this
in mind if you are working in an area where
such appliances are present. Always keep a
suitable fire extinguisher close to the work
area and familiarise yourself with its
operation before starting work. Wear eye
protection when working on fuel systems
and wash off any fuel spilt on bare skin
immediately with soap and water. Note that

fuel vapour is just as dangerous as liquid
fuel; a vessel that has just been emptied of
liquid fuel will still contain vapour and can
be potentially explosive. Petrol is a highly
dangerous and volatile liquid, and the
precautions necessary when handling it
cannot be overstressed.

Many of the operations described in this

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

When working with fuel system

components, pay particular attention to
cleanliness - dirt entering the fuel system
may cause blockages which will lead to
poor running.

Note: Residual pressure will remain in the

fuel lines long after the vehicle was last used.
When disconnecting any fuel line, first
depressurise the fuel system as described in
Section 4.

2

Air cleaner assembly -
removal and refitting

1

Removal

1 Disconnect the inlet and outlet ducts.
2 Unscrew the mounting bolts and lift the air
cleaner from the engine. 

Refitting

3 Refitting is a reversal of removal.

3

Throttle cable - removal,
refitting and adjustment

2

Removal

1 Extract the spring clip from the adjustment
ferrule located beneath the inlet manifold.
Release the cable end fitting from the linkage
the outer cable from the support bracket.
2 Working inside the car, disconnect the
cable end fitting from the top of the
accelerator pedal arm. 
3 Withdraw the throttle cable through the
bulkhead grommet.

Refitting and adjustment

4 Refitting is a reversal of removal, but adjust
the cable as follows.
5 Remove the spring clip from the adjustment
ferrule then, ensuring that the throttle cam is
fully against its stop, gently pull the cable out
of its grommet until all free play is removed
from the inner cable.
6 With the cable held in this position, ensure
that the flat washer is pressed securely
against the grommet, then fit the spring clip to
the third ferrule groove visible in front of the
rubber grommet and washer.
7 Have an assistant depress the accelerator
pedal and check that the throttle cam opens
fully and returns smoothly to its stop.

4

Fuel system -
depressurisation

1

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

Warning: The following
procedure will merely relieve the
pressure in the fuel system -
remember that fuel will still be

present in the system components, and
take precautions accordingly before
disconnecting any of them.

1 The fuel system referred to in this Section is
defined as the tank-mounted fuel pump, the
fuel filter, the fuel injectors, the fuel rail and
the pressure regulator, 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. The pressure will remain for
some time after the ignition has been
switched off, and must be relieved in a
controlled fashion when any of these
components are disturbed for servicing work.
2 Disconnect the battery negative lead.
3 Where possible, place a container beneath
the connection/union to be disconnected, and
have a large rag ready to soak up any
escaping fuel not being caught by the
container.
4 Slowly loosen the connection or union nut
to avoid a sudden release of pressure, and
position the rag around the connection, to
catch any fuel spray which may be expelled.
Once the pressure is released, disconnect the
fuel line. Plug the pipe ends, to minimise fuel
loss and prevent the entry of dirt into the fuel
system.

5

Fuel pump - removal and
refitting

3

Refer to Part B, Section 5.

6

Fuel gauge sender unit -
removal and refitting

3

Refer to Part A, Section 6.

7

Fuel tank - removal and
refitting

3

Refer to Part A, Section 7, noting that it will

be necessary to depressurise the fuel system
as the feed and return hoses are
disconnected from the fuel pump which is
located inside the tank. It will also be
necessary to disconnect the wiring connector
from the fuel pump before lowering the tank
out of position.

8

Unleaded petrol - general
information and usage

Note: The information given in this Chapter is
correct at the time of writing. If updated
information is thought to be required, check
with a Peugeot dealer. If travelling abroad,
consult one of the motoring organisations (or a
similar authority) for advice on the fuel
available.

1 With the exception of the XU9JA engine
(fitted to 1.9 GTI models without a catalytic
converter), all engines can be operated on 95
RON unleaded petrol. The XU9JA engine
should not be operated on 95 RON unleaded
petrol.
2 No adjustments to the ignition timing are
necessary in order to operate engines on 95
RON unleaded petrol, with the exception of
the XU5J and XU5JA engines, which must
both have the ignition timing retarded by 2°.
Refer to Chapter 5B for details of ignition
timing adjustment.
3 Do not operate an engine equipped with a
catalytic converter on leaded petrol. If a
catalytic converter is fitted, unleaded petrol
must be used at all times.

Engine

Code

Retard ignition by

XU5J

180A

2° (95 or 97/98 RON
unleaded)

XU5JA

B6D

2° (95 or 97/98 RON
unleaded)

XU5JA/K

B6E

None (95 or 97/98
RON unleaded)

XU9JA/K

D6B

None (97/98 RON
leaded or unleaded)

XU9JA/Z

DKZ

None (95 or 97/98
RON unleaded)

XU9JA/L

DKZ

None (95 or 97/98
RON unleaded)

XU9J1/Z

DFZ

None (95 or 97/98
RON unleaded)

XU9J1/L

DFZ

None (95 or 97/98
RON unleaded)

9

Fuel injection systems -
general information

Bosch LE2-Jetronic system

A roller type electric pump located in the

fuel tank pumps fuel through the filter to the
injectors via a fuel distribution rail. The
electronic control unit (ECU) which is
triggered by the ignition circuit sends
impulses to the injectors which operate
simultaneously and inject fuel in the vicinity of
the inlet valves. The electronic control unit is
provided with sensors to determine engine
temperature, speed and load, and the
quantity of air entering the engine. This
information is computed to determine the
period of injection.

For cold starting, additional fuel is provided

and, to compensate for this, additional air is
provided by a supplementary air device.

Bosch LU2-Jetronic system

The principle of operation of the

LU2-Jetronic system is similar to that
described above for the LE2-Jetronic system,
the only significant difference is that the
LU2-Jetronic system incorporates an oxygen
sensor in the exhaust system. This enables
the ECU to carry out fine fuel mixture adjust-
ment, to allow the use of a catalytic converter.

4C•2 Fuel system - multi-point fuel injection engines

Bosch Motronic M1.3 system

The Bosch Motronic fuel injection system is

designed to meet stringent emission control
legislation whilst still providing excellent
engine performance and fuel economy. The
system is under the overall control of the
Motronic M1.3 engine management system,
which also controls the ignition timing.

The principle of operation of the system is

similar to that described above for the
LE2-Jetronic system, noting the following
differences.

a) A double-barrel throttle housing is used

with two throttle valves operating
simultaneously.

b) An oxygen sensor Is fitted to the exhaust

system which allows fine mixture
adjustment to enable the use of a catalytic
converter.

c) A TDC sensor is used to provide the ECU

with information on crankshaft speed and
position.

10 Fuel injection system -

checks and adjustment

3

General information

1 If a fault appears in the fuel injection
system, first ensure that all the system wiring
connectors are securely connected and free
of corrosion. Ensure that the fault is not due to
poor maintenance; ie, check that the air
cleaner filter element is clean, the spark plugs
are in good condition and correctly gapped,
the valve clearances are correctly adjusted,
the cylinder compression pressures are
correct, the ignition timing is correct (where
adjustable), and that the engine breather
hoses are clear and undamaged, referring to
Chapters 1, 2 and 5 for further information.
2 If these checks fail to reveal the cause of
the problem, carry out the checks and

adjustments described in the following sub-
sections which represent the limit of work that
can be done without sophisticated test
equipment. If problems still exist, the vehicle
should be taken to a suitably-equipped
Peugeot dealer for testing. A wiring block
connector is incorporated in the engine
management circuit, into which a special
electronic diagnostic tester can be plugged.
The tester will locate the fault quickly and
simply, alleviating the need to test all the
system components individually, which is a
time-consuming operation that also carries a
risk of damaging the ECU.

Checks and adjustment

Idle speed and mixture CO content

3 Refer to Chapter 1.

Throttle initial position - LE2-Jetronic
system

4 Run the engine to normal operating
temperature - indicated when the electric
cooling fan has cut in and out twice. The
ignition timing must be correctly adjusted, as
described in Chapter 5B.
5 Connect a vacuum gauge to the test point
in the distributor vacuum advance line (see
illustration).
6 Check that the throttle movement is
smooth.
7 With the engine stopped turn the air screw
fully in (see illustration).
8 Prise the tamperproof cap from the throttle
stop screw (see illustration).
9 Unscrew the throttle stop screw then
retighten it until it just touches the throttle
lever. Tighten the screw a further four
complete turns.
10 Start the engine and allow it to idle. Turn
the throttle stop screw to obtain an idle speed
of 650 rpm (XU5J engines) or 600 rpm (XU5JA
and XU9JA engines). Check that the vacuum
reading shown on the gauge does not exceed
50 mm Hg (65 mbar) and if necessary adjust
the throttle stop screw.
11 Now turn the air screw in the throttle
housing as necessary to obtain the specified
idling speed.
12 Stop the engine and adjust the throttle
switch, as described below.

Throttle initial position - LU2-Jetronic
and Motronic M1.3 systems 

13 The throttle initial position is set in
production, and will not normally require
adjustment unless the throttle housing has
been tampered with. Adjustment should be
entrusted to a Peugeot dealer.

Throttle switch - LE2-Jetronic system

14 Pull the connector from the throttle switch
(see illustration).
15 Connect a voltmeter between the middle
terminal on the connector and earth.
16 Pull the connector from the ignition
amplifier (see Chapter 5B), then operate the
starter motor and check that there is a reading
of at least 9 volts.
17 Disconnect the air hose from the throttle
housing.
18 On all engines except XU5JA and XU9JA,
position a 0.30 mm feeler blade between the
throttle stop screw and the throttle lever.
19 Loosen the two throttle switch screws.
20 Connect an ohmmeter between terminals
18 and 2 on the throttle switch, then rotate the
switch until the internal contacts close and the
reading is zero ohms. Tighten the screws with
the switch in this position.
21 Remove the feeler blade (where
applicable) and on all engines, insert in its
place a 0.70 mm feeler blade. The internal
contacts should now be separated and the
reading on the ohmmeter infinity. If not, repeat
the procedure in paragraph 19.
22 Remove the feeler blade.

Fuel system - multi-point fuel injection engines  4C•3

4C

10.8  Prise the tamperproof cap from the

throttle stop screw (arrowed) and adjust as

described in text

10.14  Removing the throttle switch

connector

10.5  To check the throttle initial position,

connect a vacuum gauge to the 

test point (1)

10.7  Turn the air screw fully in

23 Check the full throttle operation by
connecting an ohmmeter between terminals
18 and 3, then fully opening the throttle so
that dimension X is 4.0 mm (see illustration).
The internal contacts should close and the
ohmmeter reading be zero.
24 If the switch does not operate correctly it
should be renewed.

Throttle switch - LU2-Jetronic and
Motronic M1.3 systems

25 The throttle initial position must be correct
before attempting to adjust the throttle switch.
26 Slacken the throttle switch securing
screws.
27 Turn the switch unit fully clockwise, then
turn it slowly back until the idling contacts are
heard to close.
28 Tighten the securing screws.
29 Pull the wiring from the switch, then
connect an ohmmeter between terminals 2
and 18 in the switch (see illustration). The
ohmmeter should read zero.
30 Operate the throttle linkage, and the
ohmmeter should read infinity.
31 If the readings are not correct, repeat the
procedure described in paragraphs 26 to 30
inclusive.
32 Connect the ohmmeter between switch
terminals 3 and 18. The ohmmeter should
read infinity.
33 Fully open the throttle, and the ohmmeter
should read zero.
34 If the specified readings cannot be
obtained, renew the switch.
35 Reconnect the switch wiring plug on
completion.

11 Fuel injection system

components - removal and
refitting

3

Note: Although some of the components may
differ slightly in detail, the following
procedures are applicable to all three multi-
point fuel injection systems. It is advisable to
check the availability of individual components
with your Peugeot dealer before dismantling.

Fuel injectors

Note: Refer to the warning note in Section 1
before proceeding. Ensure that the working
area is clean before removing the injectors,
and ensure that no dirt is allowed to enter the
system during the procedure. No attempt
should be made to overhaul the injectors. If a
fault or contamination is suspected, seek
specialist advice.
1 Disconnect the battery negative lead.
2 Disconnect the wiring plugs from the fuel
injectors, labelling them if necessary to ensure
correct refitting.
3 Disconnect the vacuum hose from the top
of the fuel pressure regulator.
4 Unscrew the four bolts securing the fuel rail
to the inlet manifold (two upper bolts, and two
bolts at the right-hand end of the rail), then

carefully lift the rail, complete with pressure
regulator and fuel injectors, from the inlet
manifold, taking care not to strain any of the
hoses or pipes.
5 To remove a fuel injector from the fuel rail,
carefully remove the metal securing clip, then
pull the injector from the rail. Be prepared for
fuel spillage, and take adequate precautions.
6 Refitting is a reversal of removal, but fit new
injector O-rings.

Fuel pressure regulator

Note: Refer to the warning note in Section 1
before proceeding. Ensure that the working
area is clean and that no dirt is allowed to
enter the system during the procedure.
7 For improved access to the lower pressure
regulator securing nut, proceed as described
in paragraphs 3 and 4.
8 If not already done, disconnect the vacuum
hose from the top of the pressure regulator.
9 Slacken the hose clip, and disconnect the
fuel return hose from the bottom of the
pressure regulator. Be prepared for fuel
spillage, and take adequate precautions.
10 Unscrew the two bolts securing the
pressure regulator to the fuel rail bracket
assembly, whilst counter holding the nuts.
Note that on some models, a hose bracket is
secured by the upper bolt.

11 Pull the regulator from the end of the fuel
rail, and recover the O-ring.
12 Refitting is a reversal of removal, but use a
new O-ring when refitting the pressure
regulator to the fuel rail, and where applicable,
use new injector O-rings.

Throttle position switch

13 Disconnect the battery negative lead.
14 Release the securing clip and disconnect
the wiring plug from the switch.
15 Remove the two securing screws, then
withdraw the switch from the throttle body.
16 Refitting is a reversal of removal, but on
completion, adjust the switch as described in
Section 10.

Throttle housing

17 Disconnect the battery negative lead.
18 Release the securing clip, and disconnect
the wiring plug from the throttle position
switch.
19 Loosen the securing clamp, and
disconnect the air trunking from the front of
the throttle housing.
20 Disconnect the throttle cable, with
reference to Section 3.
21 Disconnect the vacuum and/or breather
hoses from the throttle housing, noting their
locations to ensure correct refitting.
22 Unscrew the three throttle housing
securing nuts, and recover the washers.
Remove the throttle cable bracket from the
top throttle housing securing stud, noting its
orientation.
23 Withdraw the throttle housing from the
inlet manifold.
24 Refitting is a reversal of removal, bearing
in mind the following points.

a) Ensure that the vacuum and/or breather

hoses are correctly reconnected, as noted
before removal.

b) After refitting the throttle housing, check

the adjustment of the throttle cable, as
described in Section 3.

c) On completion, if any work has been

carried out on the housing, check the
adjustment of the throttle switch, as
described in Section 10.

Supplementary air (cold start)
device

25 Remove the battery as described in
Chapter 5A.
26 Disconnect the air hoses then unbolt the
airflow sensor and bracket. Disconnect the
wiring.
27 Unscrew the supplementary air device
bracket nuts and disconnect the wiring.
28 Tilt the assembly and coolant outlet
housing (without disconnecting the coolant
hoses) and remove the concealed mounting
bolt.
29 Disconnect the air hoses, then remove the
remaining mounting bolt and withdraw the
unit.
30 Refitting is a reversal of removal.

4C•4 Fuel system - multi-point fuel injection engines

10.23  Full throttle dimension “X”

4

Throttle lever

7

Throttle housing
X = 4.0 mm

10.29  Throttle switch terminal

identification - LU2-Jetronic and Motronic

M1.3 systems

Coolant temperature sensor

31 Refer to Chapter 3, Section 7.

Electronic control unit (ECU)

32 Refer to Part B, Section 11.

Fuel injection system fuses and
relays

33 Refer to Part B, Section 11.

12 Inlet manifold - removal and

refitting

3

Note: The following procedure is applicable to
all three multi-point fuel injection systems, but
slight differences in component layout may be
encountered.

Removal

1 Disconnect the battery negative lead.
2 Slacken the retaining clip, then disconnect
the inlet duct from the throttle housing and
recover the sealing ring.

3 Disconnect the throttle inner cable from the
throttle cam, then withdraw the outer cable
from the mounting bracket, along with its flat
washer and spring clip.
4 Depress the retaining clip and disconnect
the wiring connector from the throttle position
switch.
5 Release the retaining clips (where fitted)
and disconnect all the relevant vacuum and
breather hoses from the manifold. Make
identification marks on the hoses to ensure
that they are connected correctly on refitting.
6 Bearing in mind the information given in
Section 4, slacken the retaining clips and
disconnect the fuel feed and return hoses
from the fuel rail.
7 Depress the retaining tangs and disconnect
the wiring connectors from the four injectors.
Free the wiring from any relevant retaining
clips and position it clear of the manifold.
8 Where necessary, undo the retaining bolts
and remove the support bracket from the
underside of the manifold.
9 Undo the manifold retaining nuts and
withdraw the manifold from the engine

compartment. Recover the four manifold seals
and discard them; new ones must be used on
refitting.

Refitting

10 Refitting is a reverse of the relevant
removal procedure, noting the following
points:

a) Ensure that the manifold and cylinder

head mating surfaces are clean and dry,
then locate the new seals in their recesses
in the manifold.

b) Ensure that all relevant hoses are

reconnected to their original positions and
are securely held (where necessary) by
the retaining clips.

c) Adjust the throttle cable as described in

Section 3.

Fuel system - multi-point fuel injection engines  4C•5

4C

4C•6

Notes

4D

Chapter 4  Part D:
Exhaust and emission control systems

Air inlet heating system components - removal and refitting  . . . . . . 4
Catalytic converter - general information and precautions  . . . . . . . . 7
Crankcase ventilation system components - removal and refitting  . 5
Electro-pneumatic ignition timing retarding system components -

removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Emission control system check . . . . . . . . . . . . . . . . . . . .See Chapter 1
Exhaust manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 3

Exhaust system - removal and refitting  . . . . . . . . . . . . . . . . . . . . . . . 2
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Fuel vapour recirculation system components - removal and 

refitting  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

General information  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Fluid leaks and hoses check  . . . . . . . . . . . . . . . . . . . . . .See Chapter 1

4D•1

Contents

Easy, suitable for
novice with little
experience

Fairly easy, suitable
for beginner with
some experience

Fairly difficult,
suitable for competent
DIY mechanic

Difficult, suitable for
experienced  DIY
mechanic

Very difficult,
suitable for expert DIY
or  professional

Degrees of difficulty

5

4

3

2

1

1

General information

Exhaust system

1 The exhaust system consists of front,
intermediate and rear sections, the number
varying according to model. The system is
suspended from the underbody on rubber
mountings, and bolted to the exhaust
manifold at the front. Flanged joints
incorporating gasket seals or pipe clamps are
used to secure the sections. The front section
downpipe is of twin, or “siamesed” type and is
attached to the manifold by a flanged joint
incorporating compression springs or by a
single spherical joint. On TU series engines, a
ball-and-socket type joint is provided
between the front downpipe and intermediate
pipes, to allow for engine movement.
2 Later fuel-injected models are equipped
with a catalytic converter as part of the
exhaust emission control system.

Emission control systems

3 Various systems may be fitted to reduce the
emission of unburned hydrocarbons and
harmful exhaust gases into the atmosphere.
Basically, these systems can be divided as
follows:

a) Air inlet heating system.
b) Crankcase ventilation system.
c) Electro-pneumatic ignition timing

retarding system.

d) Catalytic converter.
e) Fuel vapour recirculation system.

4 The operation of the systems is described
briefly in the following paragraphs.

Air inlet heating system

5 This system is fitted to certain carburettor
and all single-point fuel injection models, and
assists the vaporisation of the fuel, providing
more complete combustion of the fuel/air
mixture (see illustration). This is achieved by
controlling the temperature of the air entering
the engine.

6 The air drawn through the air inlet pipe from
the engine compartment is mixed with hot air
drawn from a shroud around the exhaust
manifold. The proportions of hot and cold air
are controlled by the position of a flap valve,
which in turn is controlled by a wax
thermostat and a vacuum capsule (connected
to the inlet manifold).

1.5  Typical air intake heating system

1 Air cleaner
2 Air ducting

3 Exhaust manifold

hot air duct

4 Flap valve
5 Wax thermostat

a Cold air
b Hot air