Peugeot 405 Haynes (petrol). Manual - part 15

1

General information and
precautions

The fuel system consists of a fuel tank

mounted under the rear of the car, a
mechanical fuel pump, and a carburettor. The
fuel pump is operated by an eccentric on the
camshaft, and is mounted on the rear of the
cylinder head. The air cleaner contains a
disposable paper filter element, and
incorporates a flap valve air temperature
control system; this allows cold air from the
outside of the car, and warm air from the
exhaust manifold, to enter the air cleaner in
the correct proportions.

The fuel pump lifts fuel from the fuel tank to

the carburettor via a filter located in the rear of
the engine compartment, and supplies it to the
carburettor via an anti-percolation chamber.
The anti-percolation chamber ensures that the
supply of fuel to the carburettor is kept at a
constant pressure, and is free of air bubbles.
Excess fuel is returned from the anti-
percolation chamber to the fuel tank.

The carburettor is either a Solex 34-34 Z1 or

Solex 32-34 Z2 twin-choke carburettor, or
Weber 36TLP single-choke carburettor (see
Section 11), mixture enrichment for cold starting
is by automatic choke on the Solex carburettor
and a cable-operated choke control on the
Weber carburettor. On the Solex carburettor a
vacuum-operated choke unloader, accelerator
pump and full load enrichener device are fitted
to govern the fuel requirements of the engine
over its full operating range.

The exhaust system consists of three or

four sections according to model. The front
pipe is in one or two sections; where it is in
two sections the rear section may be plain or
include a catalytic converter, where it is in one
section it may include a catalytic converter. All
models are fitted with an Intermediate pipe
and silencer, and a tailpipe and silencer. The
system is suspended throughout its entire
length by rubber mountings.

2

Air cleaner assembly -
removal and refitting

2

Removal

TU engine

1 Slacken the retaining clips (where fitted),
and disconnect the vacuum hose and
breather hose from the front of the air cleaner
housing-to-carburettor duct (see illustration).
Where the crimped-type Peugeot hose clips
are fitted, cut the clips and discard them; use
standard worm-drive hose clips on refitting.
2 Slacken the retaining clips, then lift the duct
off the top of the carburettor and air cleaner
housing. Disconnect the air temperature
control valve hose from the end of the duct,
and remove the duct from the engine
compartment 

(see illustrations). Recover the

rubber sealing ring(s) from the top of the
carburettor and/or air cleaner housing (as
applicable).
3 Disconnect the inlet duct from the front of

the air cleaner housing, and remove the air
cleaner housing from the engine
compartment.
4 To remove the inlet duct assembly, undo
the retaining bolts securing the duct to the
left-hand wing valance, then release the
fastener securing the rear of the duct to the
cylinder head (see illustration). Disconnect
the hot-air inlet hose from the exhaust
manifold shroud, and remove the duct and
hose assembly from the engine compartment.

XU engine

5 Using an Allen key, unscrew the bolt
securing the air inlet duct to the top of the
carburettor. Loosen the clip and disconnect
the duct (see illustration).
6 Loosen the clip and disconnect the air inlet
duct from the filter housing top cover.
7 Release the clips and remove the top cover
from the air filter housing.
8 Remove the filter element from inside the
lower housing.
9 Release the lower housing from the
mounting rubbers then disconnect the inlet
duct and hoses as applicable.

Refitting

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

a) Examine the rubber sealing ring(s) for

signs of damage or deterioration, and if
necessary renew. Note that, on some
models, the carburettor seal is fitted with
an O-ring; this should also be renewed if
it is damaged.

4A•2 Fuel/exhaust systems - carburettor models

2.1  On the TU engine disconnect the

vacuum and breather hoses (arrowed)

from the front of the duct . . .

2.2b  . . . and remove the duct,

disconnecting the air temperature control

valve hose (arrowed)

2.5  On the XU engine unscrew the bolt

securing the air inlet duct, 

then loosen the clip

2.4  Undo the intake duct front bolt then

release the rear fastener, and remove the

duct and hose assembly (TU engine)

2.2a  . . . slacken the retaining clips . . .

Warning: Many of the
procedures in this Chapter
require the removal of fuel lines

and connections, which may result in
some fuel spillage. Before carrying out
any operation on the fuel system, refer 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.

b) Where applicable, ensure that the air

cleaner housing locating peg is correctly
engaged with its mounting on the top of
the transmission (see illustration).

c) Prior to tightening the air cleaner-to-

carburettor duct retaining clips, ensure
that the duct is correctly seated on both
the air cleaner housing and carburettor
flanges.

3

Air cleaner air temperature
control system - information
and component renewal

2

General information

TU engine

1 The system is controlled by a heat-sensitive
vacuum switch, mounted in the end of the air
cleaner housing-to-carburettor duct. When
the engine is started from cold, the switch is
open, allowing inlet manifold depression to
act on the air temperature control valve
diaphragm in the inlet duct. This vacuum
causes the diaphragm to rise, drawing a flap
valve across the cold-air inlet, thus allowing
only (warmed) air from the exhaust manifold to
enter the air cleaner.
2 As the temperature of the exhaust-warmed
air in the air cleaner-to-carburettor duct rises,
the wax capsule in the vacuum switch
deforms and closes the switch, cutting off the
vacuum supply to the air temperature control
valve assembly. As the vacuum supply is cut,
the flap is gradually lowered across the hot-air

inlet until, when the engine is fully warmed-up
to normal operating temperature, only cold air
from the front of the car is entering the air
cleaner.
3 To check the system, allow the engine to
cool down completely, then slacken the
retaining clip and disconnect the inlet duct
from the front of the control valve assembly;
the flap valve in the duct should be securely
seated across the hot-air inlet. Start the
engine; the flap should immediately rise to
close off the cold-air inlet, and should then
lower steadily as the engine warms up, until it
is eventually seated across the hot-air inlet
again.
4 To check the vacuum switch, disconnect
the vacuum pipe from the control valve when
the engine is running, and place a finger over
the pipe end. When the engine is cold, full
inlet manifold vacuum should be present in
the pipe, and when the engine is at normal
operating temperature, there should be no
vacuum in the pipe.
5 To check the air temperature control valve
assembly, slacken the retaining clip and
disconnect the inlet duct from the front of the
valve assembly; the flap valve should be
securely seated across the hot-air inlet.
Disconnect the vacuum pipe, and suck hard
at the control valve stub; the flap should rise
to shut off the cold-air inlet.
6 If either component is faulty, it must be
renewed.

XU engine

7 Cold air is drawn into the system from the
inlet duct fitted to the front panel.

8 Hot air is drawn from the collector plate
over the exhaust manifold. These two ducts
join together at the air inlet mixer housing
which contains a control flap operated by a
wax thermostat (see illustrations).
9 When the engine is cold the thermostat
contracts and the control flap closes off the
cold air duct and opens the hot air duct. As
the air being collected from the exhaust
manifold becomes warmer, so the thermostat
progressively closes off the warm air duct and
opens the cold air duct.
10 If the thermostat should fail, renew the
mixer housing.
11 All the ducts are held by worm drive clips.
12 Additional breather pipes are connected
to the air filter housing on certain models.

Vacuum switch 
(TU engine) - renewal

13 Remove the air cleaner housing-to-
carburettor duct, as described in para-
graphs 1 and 2 of Section 2.
14 Bend up the tangs on the switch retaining
clip, then remove the clip, along with its seal,
and withdraw the switch from inside the duct
(see illustrations). Examine the seal for damage
or deterioration, and renew if necessary.
15 On refitting, ensure that the switch and
duct mating surfaces are clean and dry, and
position the switch inside the duct.
16 Fit the seal over the switch unions, and
refit the retaining clip. Ensure that the switch
is pressed firmly against the duct, and secure
it in position by bending down the retaining
clip tangs. Refit the duct as described in
Section 2.

Fuel/exhaust systems - carburettor models  4A•3

3.8b  Wax thermostat on the air inlet mixer

housing (XU engine)

3.14c  . . . then withdraw the vacuum

switch from inside the duct

3.14b  . . . and seal . . .

3.14a  Remove the retaining clip . . .

3.8a  Hot-air collector plate on exhaust

manifold (XU engine)

4A

2.10  Air cleaner housing peg and

mounting rubber (arrowed)

Air temperature control valve
(TU engine) - renewal

17 Disconnect the vacuum pipe from the air
temperature control valve, then slacken the
retaining clips securing the inlet ducts to the
valve (see illustration).
18 Disconnect both inlet ducts and the hot-
air inlet hose from the control valve assembly,
and remove it from the vehicle.
19 Refitting is the reverse of the removal
procedure, noting that the air temperature
control valve assembly can only be renewed
as a complete unit.

4

Fuel pump - 
testing, removal and refitting

2

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

Testing

1 To test the fuel pump on the engine,
disconnect the outlet pipe which leads to the
carburettor. Hold a wad of rag by the pump
outlet while an assistant spins the engine on
the starter. Keep your hands away from the
electric cooling fan. Regular spurts of fuel
should be ejected as the engine turns. Be
careful not to spill fuel onto hot engine
components.
2 The pump can also be tested by removing
it. With the pump outlet pipe disconnected
but the inlet pipe still connected, hold the wad
of rag by the outlet. Operate the pump lever
by hand, moving it in and out; if the pump is in
a satisfactory condition, the lever should
move and return smoothly, and a strong jet of
fuel should be ejected.

Removal

3 Identify the pump inlet and outlet hoses,
and slacken both retaining clips (see
illustration). Where the crimped-type
Peugeot hose clips are fitted, cut the clips and
discard them; use standard worm-drive hose
clips on refitting. Place wads of rag beneath
the hose unions to catch any spilled fuel, then
disconnect both hoses from the pump; plug
the hose ends to minimise fuel loss.

TU engine

4 Where fitted remove the insulating cover
from the fuel pump, then slacken and remove
the bolts securing the pump to the rear of the
cylinder head. Remove the pump along with
its insulating block. Check the block and
renew it if necessary.

XU engine

5 Unscrew the nuts securing the pump to the
distributor end of the cylinder head and lift off
the pump (see illustration).
6 Remove the insulating block from the studs
on the cylinder head.

Refitting

7 Ensure that the pump and cylinder head
mating surfaces are clean and dry, then offer
up the insulating block and refit the pump to
the cylinder head. Tighten the pump retaining
bolts/nuts to the specified torque, then refit
the pump insulating cover where fitted
8 Reconnect the inlet and outlet hoses to the
relevant pump unions, and securely tighten
their retaining clips.

5

Fuel gauge sender unit -
removal and refitting

3

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

Removal

1 Disconnect the battery negative lead.

2 For access to the sender unit, fold the rear
seat cushion forwards or remove the rear
seats as described in Chapter 11.
3 Using a screwdriver, carefully prise the
plastic access cover from the floor to expose
the sender unit (see illustration).
4 Disconnect the wiring connector from the
sender unit (see illustration).

5 Mark the hoses for identification purposes,
then slacken the feed and return hose clips.
Where the crimped-type Peugeot hose clips
are fitted, cut the clips and discard them; use
standard worm-drive hose clips on refitting.
Disconnect both hoses from the top of the
sender unit, and plug the hose ends.
6 Noting the alignment marks on the tank,
sender unit and the locking ring, unscrew the
ring and remove it from the tank. This is best
achieved by using a screwdriver on the raised
ribs of the locking ring, as follows. Carefully
tap the screwdriver to turn the ring anti-
clockwise until it can be unscrewed by hand.
7 Carefully lift the sender unit from the top of
the fuel tank, taking great care not to bend the
sender unit float arm, or to spill fuel onto the
interior of the vehicle. Recover the rubber
sealing ring and discard it - a new one must
be used on refitting. If necessary remove the
filter from the bottom of the unit and wash it in
clean fuel.

4A•4 Fuel/exhaust systems - carburettor models

3.17  Air temperature control valve

assembly (TU engine)

4.5  Removing the fuel pump (XU engine)

5.4  Electrical plug (A) and fuel hose

connections (B) on fuel gauge sender

5.3  Remove the plastic access cover . . .

4.3  Arrows on raised fuel pump unions

indicate the direction of fuel flow

Tape the connector to the
vehicle body, in order to
prevent it from disappearing
behind the tank .

Refitting

8 Refitting is a reversal of the removal
procedure, noting the following points:

a) Prior to refitting, fit a new rubber sealing

ring to the sender unit.

b) Refit the sender unit to the tank, aligning

its arrow with the centre of the three
alignment marks on the fuel tank. Secure
the sender in position with the locking
ring, and check that the locking ring,
sender unit and fuel tank marks are all
correctly aligned.

c) Ensure that the feed and return hoses are

correctly reconnected and securely
retained by their clips.

6

Fuel tank - 
removal and refitting

3

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

Removal

1 Before removing the fuel tank, all fuel must
be drained from the tank. Since a fuel tank
drain plug is not provided, it is preferable to
carry out the removal operation when the tank
is nearly empty. Before proceeding,
disconnect the battery negative lead and
syphon or hand-pump the remaining fuel from
the tank.
2 Remove the exhaust system and relevant
heat shield(s) as described in Section 16.
3 From underneath the vehicle, disconnect
the handbrake cable at the equaliser bracket.
4 Release the handbrake primary cable from
the clips in the fuel tank. Position the cable
clear of the tank, so that it will not hinder the
removal procedure.
5 Disconnect the wiring connector from the
fuel gauge sender unit, as described in
Section 5.
6 Working at the right-hand side of the fuel
tank, release the retaining clips then
disconnect the filler neck vent pipe and main
filler neck hose from the fuel tank/filler neck.
Where necessary, also disconnect the
breather hose(s). Some breather hoses are
joined to the tank with quick-release fittings; to
disconnect these fittings, slide the cover along

the hose then depress the centre ring and pull
the hose out of its fitting (see illustration).
7 Trace the fuel feed and return hoses back
from the right-hand side of the tank to their
union with the fuel pipes. Slacken the
retaining clips and disconnect both hoses
from the fuel pipes. Where the crimped-type
Peugeot hose clips are fitted, cut the clips and
discard them; use standard worm-drive hose
clips on refitting. Plug the hose and pipe ends,
to prevent the entry of dirt into the system.
8 Place a trolley jack with an interposed block
of wood beneath the tank, then raise the jack
until it is supporting the weight of the tank.
9 Slacken and remove the retaining nut and
bolts, then remove the two support rods from
the underside of the tank (see illustration).
10 Slowly lower the fuel tank out of position,
disconnecting any other relevant vent pipes as
they become accessible (where necessary),
and remove the tank from underneath the car.
11 If the tank is contaminated with sediment
or water, remove the sender unit (Section 5),
and swill the tank out with clean fuel. The tank
is injection-moulded from a synthetic material
- if seriously damaged, it should be renewed.
However, in certain cases, it may be possible
to have small leaks or minor damage repaired.
Seek the advice of a specialist before
attempting to repair the fuel tank.

Refitting

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

a) When lifting the tank back into position,

take care to ensure that none of the hoses

become trapped between the tank and
vehicle body.

b) Ensure that all pipes and hoses are

correctly routed, and securely held in
position with their retaining clips.

c) Reconnect the handbrake cables and

adjust the handbrake (see Chapter 9).

d) On completion, refill the tank with a small

amount of fuel, and check for signs of
leakage prior to taking the vehicle out on
the road.

7

Accelerator cable - removal,
refitting and adjustment

2

Removal

1 Working in the engine compartment, free
the accelerator inner cable from the
carburettor throttle cam, then pull the outer
cable out from its mounting bracket rubber
grommet  (see illustrations). Where fitted,
slide the flat washer off the end of the cable,
and remove the spring clip.
2 Working back along the length of the cable,
free it from any retaining clips or ties, noting
its correct routing.
3 Where necessary remove the lower trim
from below the driver’s side of the facia panel.
4 Working from inside the vehicle, disconnect
the cable from the accelerator pedal by
depressing the lugs on the plastic end fitting
and pushing the fitting from the pedal (see
illustration).

Fuel/exhaust systems - carburettor models  4A•5

7.1a  Accelerator cable connection on the

throttle quadrant (arrowed)

8  Cover     9  Centre ring     10  Hose

7.4  Accelerator cable connection to

accelerator pedal (arrowed)

7.1b  Outer cable end fitting

6.9  Fuel tank support strap bolt

4A

6.6  Tank breather quick-release connector

5 Release the outer cable from its retainer on
the pedal mounting bracket, then tie a length
of string to the end of the cable.
6 Return to the engine compartment, release
the cable grommet from the bulkhead and
withdraw the cable. When the end of the
cable appears, untie the string and leave it in
position - it can then be used to draw the
cable back into position on refitting.

Refitting

7 Tie the string to the end of the cable, then
use the string to draw the cable into position
through the bulkhead. Once the cable end is
visible, untie the string, then clip the outer
cable into its pedal bracket retainer, and clip
the inner cable into position in the pedal end.
The remaining procedure is a reversal of
removal, but adjust it as follows.

Adjustment

8 Remove the spring clip from the accelerator
outer cable. 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.
9 With the cable held in this position, refit the
spring clip to the last exposed outer cable
groove in front of the rubber grommet and
washer. When the clip is refitted and the outer
cable is released, there should be only a small
amount of free play in the inner cable (see
illustration).
10 Have an assistant depress the accelerator
pedal, and check that the throttle cam opens
fully and returns smoothly to its stop.
11 For models fitted with automatic
transmission refer to Chapter 7, Part B.

8

Accelerator pedal - 
removal and refitting

2

Removal

1 Disconnect the accelerator cable from the
pedal as described in Section 7.
2 Remove the screws from the pedal pivot
bush and lift out the pedal (see illustration).
3 Examine the pivot bush and shaft for signs
of wear, and renew as necessary.

Refitting

4 Refitting is a reversal of the removal
procedure, applying a little multi-purpose
grease to the pedal pivot point. On
completion, adjust the accelerator cable as
described in Section 7.

9

Choke cable - removal,
refitting and adjustment

2

Removal

1 Release the choke inner cable from the
carburettor linkage.
2 Slacken and remove the retaining bolt and
remove the outer cable retaining clamp.
3 Slacken the retaining clip securing the
rubber collar to the outer cable, and slide the
collar off the cable. Where the original
crimped-type Peugeot hose clip is still fitted,
cut the clip and discard it; use a standard
worm-drive hose clip on refitting.
4 Working back along the length of the cable,
free it from any retaining clips or ties, noting
its correct routing. Tie a length of string to the
end of the choke inner cable.
5 Working from inside the vehicle, pull the
choke lever fully out, to gain access to the
retaining screw. Unclip the choke lever from
the facia and withdraw the lever and cable
assembly from the facia, disconnecting the
wiring from the lever switch (where fitted) as it
becomes accessible. Once the end of the
cable appears through the lever aperture,
untie the string and leave it in position in the
vehicle - it can then be used to draw the cable
back into position on refitting.

Refitting

6 Tie the string to the end of the choke cable,
then use the string to draw the cable into
position through the bulkhead into the engine
compartment. Once the cable end is fully in
position, untie the string.
7 Reconnect the wiring connector (where
fitted), and clip the choke lever in its facia
panel aperture.
8 From within the engine compartment,
ensure that the outer cable is correctly seated
in the bulkhead grommet. Work along the

cable, securing it in position with all the
relevant retaining clips and ties, and ensuring
that the cable is correctly routed.
9 Slide the rubber collar and retaining clip
onto the end of the cable, then engage the
inner end of the cable with carburettor
linkage. Align the rubber collar with the
carburettor bracket, then refit the retaining
clip and securely tighten its retaining bolt.
Adjust the cable as described below.

Adjustment

10 Slacken the clip securing the rubber collar
to the outer cable. Where the crimped-type
Peugeot hose clip is still fitted, cut the clip
and discard it; use a standard worm-drive
hose clip on refitting (see illustration).
11 Ensuring that the choke lever is flush with
the facia panel and the carburettor linkage is
fully against its stop, move the outer cable in
the rubber collar until the position is found
where there is only a small amount of free play
present in the inner cable. Hold the outer
cable in this position, and securely tighten the
clip securing the rubber collar to the outer
cable.
12 Have an assistant operate the choke
lever, and check that the choke linkage closes
fully and returns smoothly to its stop. If
necessary, repeat the adjustment procedure.

10 Unleaded petrol - general

information and usage

Note: The information given in this Chapter is
correct at the time of writing. If updated
information is 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.

The fuel recommended by Peugeot is given

in the Specifications Section of this Chapter,
followed by the equivalent petrol currently on
sale in the UK.

All Peugeot 405 carburettor models are

designed to run on 95 octane petrol. Both
leaded and unleaded petrol can be used
without modification. Super leaded 
(97 octane, UK “4-star”) and super unleaded
(98 octane) petrol can also be used if wished,
though there is no advantage in doing so.

9.10  Choke cable-to-rubber collar

retaining clip (arrowed)

4A•6 Fuel/exhaust systems - carburettor models

7.9  Adjusting the accelerator cable

8.2  Accelerator pedal pivot bush

11 Carburettor - 

general information

The Solex 34-34 Z1 carburettor is a

downdraught progressive twin-venturi
instrument. The throttle linkages are arranged
so that the secondary throttle valve will not
start to open until the primary valve is about
two-thirds open, but at full throttle both valves
are fully open. The choke control is either
automatic or manual. On some early models a
carburettor cooling system was fitted which
allows the radiator cooling fan to run for a
maximum of 12 minutes after the engine has
been switched off.

The Weber 34TLP carburettor is a single

choke downdraught type instrument fitted
with a manual choke.

12 Carburettor - 

removal and refitting

3

Note: Refer to the warning note in Section 1
before proceeding. Where original crimped-
type Peugeot hose clips are still fitted, the
clips should be cut and discarded; obtain
some worm-drive hose clips for refitting.

Removal

1 Disconnect the battery negative terminal.
2 Remove the air cleaner-to-carburettor duct
as described in Section 2.
3 Disconnect the accelerator cable from the
throttle quadrant as described in Section 8.
4 Disconnect the distributor vacuum pipe
(see illustration).
5 Disconnect the float chamber breather

pipes. The upper pipe connects with the air
filter housing (see illustration).
6 Either drain the cooling system or clamp
the automatic choke and carburettor base
heating pipes, then disconnect the pipes (see
illustrations).
7 Disconnect the float chamber solenoid
valve wiring (see illustration).
8 Disconnect the fuel inlet pipe either at the
fuel pump or the fuel reservoir on the side of
the carburettor and blank off the hose.
9 Remove the single carburettor securing nut
and lift off the fuel reservoir (see illustration).
10 Remove the remaining carburettor nuts
and lift off the carburettor (see illustrations).
11 Remove the insulating spacer and/or
gasket(s)  (see illustration). Discard the
gasket(s); new ones must be used on refitting.
Plug the inlet manifold port with a wad of
clean cloth, to prevent the entry of debris.

Fuel/exhaust systems - carburettor models  4A•7

12.6a  Automatic choke coolant pipe

connection . . .

12.9  Lifting off the fuel reservoir

12.7  Disconnecting the float chamber

breather solenoid wiring

12.6b  . . . and base heating pipes

12.5  Disconnecting the float chamber

breather pipe

4A

12.4  Disconnecting the distributor 

vacuum pipe

12.10a  Remove the remaining nuts . . .

12.10b  . . . and lift off the carburettor

12.11  Removing the insulating spacer

Refitting

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

a) Ensure that the carburettor and inlet

manifold sealing faces are clean and flat.
Fit a new gasket, and securely tighten the
carburettor retaining nuts.

b) Use the notes made on dismantling to

ensure that all hoses are refitted to their
original positions and, where necessary,
are securely held by their retaining clips.

c) Where the original crimped-type Peugeot

hose clips were fitted, discard them; use
standard worm-drive hose clips when
refitting.

d) Refit and adjust the choke and

accelerator cables as described in
Sections 7 and 9.

e) Refit the air cleaner duct as described in

Section 2.

f) On completion, check and, if necessary,

adjust the idle speed and mixture settings
as described in Chapter 1.

13 Carburettor - fault diagnosis,

overhaul and adjustments

2

Fault diagnosis

1 If a carburettor fault is suspected, always
check first that the ignition timing is correctly
set, that the spark plugs are in good condition
and correctly gapped, that the accelerator
and choke cables are correctly adjusted, and
that the air cleaner filter element is clean; refer
to the relevant Sections of Chapter 1, Chapter
5 or this Chapter. If the engine is running very
roughly, first check the valve clearances as
described in Chapter 1, then check the
compression pressures as described in
Chapter 2.
2 If careful checking of all the above
produces no improvement, the carburettor
must be removed for cleaning and overhaul.
3 Prior to overhaul, check the availability of
component parts before starting work; note
that most sealing washers, screws and
gaskets are available in kits, as are some of
the major sub-assemblies. In most cases, it
will be sufficient to dismantle the carburettor
and to clean the jets and passages.

Overhaul

Note: Refer to the warning note in Section 1
before proceeding. Only carry out the
procedures described in this Section, as
special gauges are required for a more
detailed overhaul. The following procedure
applies to the Solex 34-34 Z1 carburettor.
4 Remove the carburettor from the vehicle as
described in Section 12.
5 Unscrew the idle cut-off solenoid from the
carburettor body, and remove it along with its
plunger and spring. To test the solenoid,
connect a 12-volt battery to it (positive

terminal to the solenoid terminal, negative
terminal to the solenoid body), and check that
the plunger is retracted fully into the body.
Disconnect the battery, and check that the
plunger is pushed out by spring pressure. If
the valve does not perform as expected, and
cleaning does not improve the situation, the
solenoid valve must be renewed.
6 Remove the five screws and lift off the
carburettor upper body.
7 Tap out the float pivot pin and remove the
float assembly, needle valve, and float
chamber gasket. Check that the needle valve
anti-vibration ball is free in the valve end, then
examine the needle valve tip and seat for wear
or damage. Examine the float assembly and
pivot pin for signs of wear and damage. The
float assembly must be renewed if it appears
to be leaking - shake the float to detect the
presence of fuel inside.
8 Unscrew the fuel inlet union and inspect the
fuel filter. Clean the filter housing of debris
and dirt, and renew the filter if it is blocked.
9 Undo the four screws, detach the
accelerator pump cover, and remove the
pump diaphragm and spring, noting which
way around they are fitted. Examine the
diaphragm for signs of damage and
deterioration, and renew if necessary.
Remove the choke pull-down diaphragm and
part-load enrichment diaphragms, and
examine them in the same way.
10 Unscrew the idle jet from the upper body.
11 Unscrew both the primary and secondary
combined air correction jets and emulsion
tubes.
12 Using a long thin screwdriver, unscrew
the main jets from the bottom of the emulsion
tube drillings. Invert the carburettor and catch
the jets as they fall out of the drillings.
13 Remove the idle mixture adjustment
screw tamperproof cap. Screw the screw in
until it seats lightly, counting the exact
number of turns required to do this, then
unscrew it. On refitting, screw the screw in
until it seats lightly, then back the screw off by
the number of turns noted on removal, to
return the screw to its original position.
14 Clean the jets, carburettor body
assemblies, float chamber and internal
drillings. An air line may be used to clear the
internal passages once the carburettor is fully
dismantled. Caution: If high pressure air is
directed into drillings and passages where
a diaphragm is fitted, the diaphragm is
likely to be damaged.

15 Use a straight edge to check all
carburettor body assembly mating surfaces
for distortion.
16 To test the carburettor heating element,
connect a multimeter, set to the resistance

function, between the heater wiring terminal
and the carburettor body. A resistance
reading of approximately 0.25 to 0.5 ohms
should be obtained. If an open-circuit is
present, or an extremely high resistance
reading is obtained, it is likely that the heating
element is faulty. A heating element repair kit
is available from your Peugeot dealer. To
renew the element undo the screw and
remove the retaining plate, then slide the
element holder, pin, element and insulating
plate, noting each component correct fitted
location. Fit the new components, ensuring
each one is correctly positioned, and securely
tighten the retaining screws. Note: Ensure
that the insulating plate is correctly positioned
between the heating element and body so that
there is no danger of the element shorting out
on the carburettor body.
17 On reassembly renew any worn
components and fit a complete set of new
gaskets and seals. A jet kit and a gasket and
seal kit are available from your Peugeot
dealer.
18 Reassembly is a reversal of the
dismantling procedure. Ensure that all jets are
securely locked in position, but take great
care not to overtighten them. Ensure that all
mating surfaces are clean and dry, and that all
body sections are correctly assembled with
their fuel and air passages correctly aligned.
Prior to refitting the carburettor to the vehicle,
set the float height, throttle valve fast idle and
choke pull-down settings as described below.

Adjustments

Idle speed and mixture

19 Refer to Chapter 1.

Float height setting 
(Solex carburettor)

20 Invert the carburettor body, so that the
float is at the top and the needle valve is
depressed. Measure the distance between
the upper edge of the float and the sealing
face of the upper body (with its gasket fitted).
This measurement should be as given in the
Specifications at the start of this Chapter.
21 If necessary, the float height can be
adjusted by carefully bending the small tang
on the float arm which contacts the needle
valve.

Throttle valve fast idle setting 
(Solex carburettor)

22 Invert the carburettor and pull the
carburettor choke linkage to fully close the
choke valve. The fast idle screw will butt
against the fast idle cam and force the throttle
valve open slightly.
23 Using the shank of a twist drill, measure
the clearance between the edge of the throttle
valve and bore, and compare this to the
clearance given in the Specifications at the
start of this Chapter. If necessary, adjust by
turning the fast idle adjustment screw in the
appropriate direction until the specified
clearance is obtained (see illustration).

4A•8 Fuel/exhaust systems - carburettor models

Aerosol cans of carburettor
cleaner are widely available
and can prove very useful in
helping to clear internal

passages of stubborn obstructions.

Choke pull-down setting 
(Solex carburettor)

24 Pull the carburettor choke linkage to fully
close the choke valve, and hold the linkage in
this position.
25 Attach a hand-held vacuum pump to the
choke pull-down diaphragm, and apply a
vacuum to the diaphragm so that the
diaphragm rod is pulled fully into the
diaphragm body. In the absence of a vacuum
pump, the rod can be pushed into the
diaphragm with a small screwdriver.
26 With the rod fully retracted, use the shank
of a twist drill to measure the clearance
between the edge of the choke valve and
bore, and compare this to the clearance given
in the Specifications (see illustration). If
necessary, remove the plug from the
diaphragm cover and adjust by turning the
adjustment screw. Once the pull-down setting
is correctly adjusted, refit the plug to the
diaphragm cover and remove the vacuum
pump (where used).

Float height setting 
(Weber carburettor)

27 For float and level settings, remove the
float chamber cover and hold it vertically.

28 With the gasket in position, use a steel
rule or vernier calipers to check the height of
the floats. Bend the float tongue and
connecting bars if necessary.

Choke opening after starting 
(Weber carburettor)

29 Remove the air inlet from the top of the
carburettor. Pull the choke control knob out
fully to close the choke flap.
30 Disconnect the vacuum pipe from the
anti-flood capsule.
31 Connect a hand vacuum pump (or a
modified bicycle pump) to the capsule. Apply
vacuum (400 mm Hg approx.) to the capsule.
The choke flap should open far enough to
admit a drill shank or rod 5 mm in diameter.
32 Adjust if necessary by means of the screw
on the anti-flood capsule.
33 Disconnect the vacuum pump, remake
the original vacuum connection, and close the
choke flap.
34 Having adjusted the anti-flood capsule,
move the choke opening roller into the recess
of the cam as shown (see illustration).
35 Check that the choke flap opening just
admits a drill shank or rod 8 mm in diameter.
36 Adjust by turning the nut shown (see
illustration) after removing the carburettor.

14 Inlet manifold - 

removal and refitting

3

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

Removal

1 Remove the carburettor as described in
Section 12.
2 On TU engines, drain the cooling system as
described in Chapter 1, and disconnect the
coolant hose from the base of the manifold.
3 Disconnect the brake vacuum servo hose at
the manifold.
4 Disconnect the oil filler cap breather hose
from the manifold.
5 Unbolt the oil filler tube bracket.
6 Unscrew the retaining nuts, then
manoeuvre the manifold away from the head
and out of the engine compartment. Note that
on the TU engine there is no manifold gasket.
A gasket is however fitted on XU engines. On
XU engines note the centre clamp secured by
one nut (see illustration).

Refitting

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

a) Ensure that the manifold and cylinder

head mating surfaces are clean and dry.
Fit a new gasket on XU engines, and
apply a thin coating of suitable sealing
compound to the manifold mating surface
on TU engines. Install the manifold and
tighten its retaining nuts to the specified
torque setting.

b) Ensure that all relevant hoses are

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

c) Refit the carburettor as described in

Section 12.

d) Where applicable, refill the cooling system

as described in Chapter 1.

Fuel/exhaust systems - carburettor models  4A•9

14.6  Inlet manifold centre clamp 

on the XU engine

13.36  Choke mechanical opening

adjustment nut (4) (Weber carburettor)

4A

13.23  Throttle valve fast idle setting 

(Solex carburettor)

13.34  Checking the choke mechanical

opening (Weber carburettor)

Adjust until clearance X is as specified

Adjust screw Y until clearance X is as given in
the Specifications

a  Cam     3  Roller

13.26  Choke pull-down setting (using a

screwdriver to retract the diaphragm rod)

(Solex carburettor)