zx manual

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4A*1
Chapter 4 Part A:
Fuel and exhaust systems - carburettor engines
Contents
Accelerator cable - removal, refitting and adjustment 7
Fuel gauge sender unit - removal and refitting 5
Accelerator pedal - removal and refitting 8
Fuel pump - testing, removal and refitting 4
Air cleaner air temperature control system - general
Fuel tank - removal and refitting 6
information and component renewal 3
General fuel system checks See Chapter 1
Air cleaner assembly - removal and refitting 2
General information and precautions 1
Air cleaner filter element renewal See Chapter 1
Idle speed and mixture adjustment See Chapter 1
Carburettor - general information 11
Inlet manifold - removal and refitting 15
Carburettor - removal and refitting 12
Solex 32 PBISA carburettor (1124 cc models) - fault
Choke cable - removal, refitting and adjustment 9
finding, overhaul and adjustments 13
Exhaust manifold - removal and refitting 16
Solex 32-34 Z2 carburettor (1360 cc models) - fault
Exhaust system - general information, removal and refitting 17
finding, overhaul and adjustments 14
Exhaust system check See Chapter 1
Unleaded petrol - general information and usage 10
Fuel filter - renewal See Chapter 1
Degrees of difficulty
Easy, suitable for
Fairly easy, suitable
Fairly difficult, suitable
Difficult, suitable for
Very difficult,
novice with little
for beginner with
for competent DIY
experienced DIY
suitable for expert DIY
experience
some experience
mechanic
mechanic
or professional
Specifications
Fuel pump
Type Mechanical, driven by eccentric on camshaft
Carburettor
Type:
1124 cc models Solex 32 PBISA 16
1360 cc models Solex 32-34 Z2
Designation:
1124 cc models 32 PBISA 1 6 - 4 1 1
1360 cc models 32-34 Z2 - 528
Choke type (both carburettors) Manual, cable-operated
Solex 32 PBISA carburettor data -1124 cc models
Venturi diameter 25 mm
Main jet 127.5
Idle jet 48
Air correction jet 175
Emulsion tube EM
Enrichment jet 50
Accelerator pump 40
Needle valve 1.5
Float height setting See text
Throttle valve fast idle setting 0.6 mm
Choke pull-down setting 2.8 mm
Idle speed 850 50 rpm
Idle mixture CO content 0.8 to 1.2 %

4A*2 Fuel and exhaust systems - carburettor engines
Solex 32-34 Z2 carburettor data - 1360 CC models Primary Secondary
Venturi diameter 24 mm 25 mm
Main jet 115 120
Idle jet 40
Air correction jet/emulsion tube 155 160
Bypass jet - 50
Econostat jet - 80
Accelerator pump 35
Pneumatic enrichment device 45
Needle valve 1.6
Float height setting 35 mm
Throttle valve fast idle setting 0.5 mm
Choke pull-down setting 3.0 mm
Idle speed 850 50 rpm
Idle mixture CO content 0.8 to 1.2 %
Recommended fuel
Minimum octane rating 95 RON unleaded (UK unleaded premium) or
97 RON leaded (UK "4-star")
Torque wrench settings Nm ibf ft
Fuel pump retaining bolts 16 12
Inlet manifold retaining nuts 8 6
Exhaust manifold retaining nuts 16 12
Exhaust system fasteners:
Front pipe-to-manifold nuts 30 22
Front pipe mounting bolt 35 26
Front pipe-to-intermediate pipe nuts 10 7
Clamping ring nuts 20 15
Warning: Many of the procedures
breather hose from the front of the air cleaner
1 General information and
in this Chapter require the
housing-to-carburettor duct (see illustration).
removal of fuel lines and
Where the crimped-type Citroen hose clips
precautions
connections, which may result in
are fitted, cut the clips and discard them; use
The fuel system consists of a fuel tank
some fuel spillage. Before carrying out any
standard worm-drive hose clips on refitting.
mounted under the rear of the car, a
operation on the fuel system, refer to the
2 Slacken the retaining clips, then lift the duct
mechanical fuel pump, and a carburettor. The
precautions given in "Safety first!" at the
off the top of the carburettor and air cleaner
fuel pump is operated by an eccentric on the
beginning of this manual, and follow them
housing. Disconnect the air temperature
camshaft, and is mounted on the rear of the
implicitly. Petrol is a highly-dangerous and
control valve hose from the end of the duct,
cylinder head. The air cleaner contains a
volatile liquid, and the precautions
and remove the duct from the engine
disposable paper filter element, and
necessary when handling it cannot be
compartment (see illustrations). Recover the
incorporates a flap valve air temperature
overstressed.
rubber sealing ring(s) from the top of the
control system; this allows cold air from the
carburettor and/or air cleaner housing (as
outside of the car, and warm air from the
applicable).
2 Air cleaner assembly -
exhaust manifold, to enter the air cleaner in
3 Disconnect the intake duct from the front of
removal and refitting
the correct proportions.
the air cleaner housing, and remove the air
The fuel pump lifts fuel from the fuel tank
cleaner housing from the engine
via a filter, which is mounted on the engine
compartment.
Removal
compartment bulkhead, and supplies it to the
4 To remove the intake duct assembly, undo
carburettor via an anti-percolation chamber.
1 Slacken the retaining clips (where fitted),
the retaining nut(s) securing the duct to the
The anti-percolation chamber ensures that the
and disconnect the vacuum hose and
left-hand wing valance, then release 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.
On 1124 cc models, a Solex 32 PBISA
single-choke carburettor is fitted; 1360 cc
models have a Solex 32-34 Z2 twin-choke
carburettor. On both carburettors, mixture
enrichment for cold starting is by a cable-
operated choke control.
The exhaust system consists of three
sections; the front pipe, the intermediate pipe
and silencer box, and the tailpipe and main
silencer box. The system is suspended
throughout its entire length by rubber
2.1 Disconnect the vacuum and breather
mountings.
hoses (arrowed) from the front of the duct...
2.2a . . . slacken the retaining clips . . .

Fuel and exhaust systems - carburettor engines 4A*3
2.2b . . . and remove the duct, 2.4a Undo the intake duct front retaining 2.4b . . . then release the rear fastener
disconnect.ng the air temperature control nut (arrowed)... and remove the duct and hose assembly
valve hose (arrowed)
fastener securing the rear of the duct to the
the flap is gradually lowered across the hot-air
cylinder head (see illustrations). Disconnect
intake until, when the engine is fully warmed-
the hot-air intake hose from the exhaust
up to normal operating temperature, only cold
manifold shroud, and remove the duct and
air from the front of the car is entering the air
hose assembly from the engine compartment.
cleaner.
Refitting
3 To check the system, allow the engine to
cool down completely, then slacken the
5 Refitting is a reversal of the removal
retaining clip and disconnect the intake duct
procedure, noting the following points:
from the front of the control valve assembly;
(a) Examine the rubber sealing ring(s) for
the flap valve in the duct should be securely
signs of damage or deterioration, and if
seated across the hot-air intake. Start the
necessary renew. Note that, on some
engine; the flap should immediately rise to
models, the carburettor seal is fitted with
close off the cold-air intake, and should then
an O-ring; this should also be renewed if
lower steadily as the engine warms up, until it
it is damaged.
is eventually seated across the hot-air intake
2.5 On refitting, ensure the air cleaner
(b) Ensure the air cleaner housing locating
again.
housing peg is correctly located in its
peg is correctly engaged with its
4 To check the vacuum switch, disconnect
mounting rubber (arrowed)
mounting on the top of the transmission
the vacuum pipe from the control valve when
(see illustration).
the engine is running, and place a finger over
Vacuum switch - renewal
(c) Prior to tightening the air cleaner-to-
the pipe end. When the engine is cold, full
7 Remove the air cleaner housing-to-
carburettor duct retaining clips, ensure
inlet manifold vacuum should be present in
carburettor duct, as described in paragraphs
the duct is correctly seated on both the
the pipe, and when the engine is at normal
1 and 2 of Section 2.
air cleaner housing and carburettor
operating temperature, there should be no
8 Bend up the tangs on the switch retaining
flanges.
vacuum in the pipe.
clip, then remove the clip, along with its seal,
5 To check the air temperature control valve
and withdraw the switch from inside the duct
assembly, slacken the retaining clip and
(see illustrations). Examine the seal for signs
3 Air cleaner air temperature
disconnect the intake duct from the front of
of damage or deterioration, and renew if
control system -
the valve assembly; the flap valve should be
necessary.
general Information and
securely seated across the hot-air intake.
9 On refitting, ensure the switch and duct
component renewal
Disconnect the vacuum pipe, and suck hard
mating surfaces are clean and dry, and
at the control valve stub; the flap should rise
position the switch inside of the duct.
to shut off the cold-air intake.
10 Fit the seal over the switch unions, and
General information
6 If either component is faulty, it must be
refit the retaining clip. Ensure the switch is
1 The system is controlled by a heat-sensitive
renewed.
pressed firmly against the duct, and secure it
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 intake duct. This vacuum
causes the diaphragm to rise, drawing a flap
valve across the cold-air intake, 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
3.8a Remove the retaining clip . . .
3.8b . . . and s e a l . . .
valve assembly. As the vacuum supply is cut,

4A*4 Fuel and exhaust systems - carburettor engines
3.8c . . . then withdraw the vacuum switch
3.12 Air temperature control valve
from inside the duct
4.3 Arrows on fuel pump unions indicate
assembly
the direction of fuel flow
in position by bending down the retaining clip
careful not to spill fuel onto hot engine
tangs.
bolts to the specified torque, then refit the
components.
pump insulating cover.
11 Refit the duct as described in Section 2.
2 The pump can also be tested by removing
6 Reconnect the inlet and outlet hoses to the
Air temperature control valve -
it. With the pump outlet pipe disconnected
relevant pump unions, and securely tighten
renewal
but the inlet pipe still connected, hold the wad
their retaining clips.
of rag by the outlet. Operate the pump lever
12 Disconnect the vacuum pipe from the air
by hand, moving it in and out; if the pump is in
temperature control valve, then slacken the
5 Fuel gauge sender unit -
a satisfactory condition, the lever should
retaining clips securing the intake ducts to the
move and return smoothly, and a strong jet of
removal and refitting
valve (see illustration).
fuel should be ejected.
13 Disconnect both intake ducts and the hot-
Note: Refer to the warning note in Section 1
air intake hose from the control valve
Removal
before proceeding.
assembly, and remove it from the vehicle.
Removal
3 Identify the pump inlet and outlet hoses,
14 Refitting is the reverse of the removal
and slacken both retaining clips (see
1 Disconnect the battery negative lead.
procedure, noting that the air temperature
illustration). Where the crimped-type Citroen
2 For access to the sender unit, tilt or remove
control valve assembly can only be renewed
hose clips are fitted, cut the clips and discard
the rear seats as described in Chapter 11.
as a complete unit.
them; use standard worm-drive hose clips on
3 Using a screwdriver, carefully prise the
refitting. Place wads of rag beneath the hose
plastic access cover from the floor to expose
unions to catch any spilled fuel, then
the sender unit. It is located under the left-
4 Fuel pump -
disconnect both hoses from the pump; plug
hand cover (see illustration).
testing, removal and refitting
the hose ends to minimise fuel loss.
4 Disconnect the wiring connector from the
sender unit, and tape the connector to the
4 Remove the insulating cover from the fuel
Note: Refer to the warning note in Section 1
vehicle body to prevent it disappearing behind
pump, then slacken and remove the bolts
before proceeding.
the tank (see illustration).
securing the pump to the rear of the cylinder
5 Mark the hoses for identification purposes,
Testing
head. Remove the pump along with its
then slacken the feed and return hose retaining
insulating block. Discard the insulating block:
1 To test the fuel pump on the engine,
clips. Where the crimped-type Citroen hose
a new one must be used on refitting.
disconnect the outlet pipe which leads to the
clips are fitted, cut the clips and discard them;
use standard worm-drive hose clips on
carburettor. Hold a wad of rag by the pump
Refitting
refitting. Disconnect both hoses from the top of
outlet while an assistant spins the engine on
5 Ensure the pump and cylinder head mating
the sender unit, and plug the hose ends.
the starter. Keep your hands away from the
surfaces are clean and dry, then offer up the
electric cooling fan. Regular spurts of fuel
6 Noting the alignment marks on the tank,
new insulating block and refit the pump to the
should be ejected as the engine turns. Be
sender unit and the locking ring, unscrew the
cylinder head. Tighten the pump retaining
ring and remove it from the tank. This is best
5.3 Remove the plastic access cover ...
5.4 . . . and disconnect the wiring
5.6a Note the position of the alignment
connector from the fuel gauge sender unit
marks (arrowed) on the sender unit and
(fuel-injected model shown)
locking ring . . .

Fuel and exhaust systems - carburettor engines 4A*5
5.6b . . . then unscrew the locking ring
5.7a Withdraw the sender unit from the 5.7b . . . and remove the rubber sealing
tank . . . ring
accomplished by using a screwdriver on the
drain plug is not provided, it is therefore
raised ribs of the locking ring, as follows.
preferable to carry out the removal operation
Carefully tap the screwdriver to turn the ring
when the tank is nearly empty. Before
anti-clockwise until it can be unscrewed by
proceeding, disconnect the battery negative
hand (see illustrations).
lead, and syphon or hand-pump the
7 Carefully lift the sender unit from the top of
remaining fuel from the tank.
the fuel tank, taking great care not to bend the
2 Remove the exhaust system and relevant
sender unit float arm, or to spill fuel onto the
heat shield(s) as described in Section 17.
interior of the vehicle. Recover the rubber
3 Disconnect the two handbrake cables from
sealing ring and discard it - a new one must
the handbrake lever, as described in Chap-
be used on refitting (see illustrations).
ter 9.
4 From underneath the vehicle, remove the
Refitting
retaining clips, and release each handbrake
Refitting is a reversal of the removal
cable from its guides on the underside of the
6.4 Handbrake cable-to-fuel tank retaining
procedure, noting the following points:
fuel tank (see illustration). Position both
clip (arrowed)
(a) Prior to refitting, fit a new rubber sealing
cables clear of the tank, so that they will not
ring to the sender unit,
hinder the removal procedure.
Plug the hose and pipe ends, to prevent the
(b) Refit the sender unit to the tank, aligning
5 Disconnect the wiring connector from the
entry of dirt into the system.
its arrow with the centre of the three
fuel gauge sender unit, as described in
8 Place a trolley jack with an interposed block
alignment marks on the fuel tank. Secure
Section 5.
of wood beneath the tank, then raise the jack
the sender in position with the locking
6 Working at the right-hand side of the fuel
until it is supporting the weight of the tank.
ring, and check that the locking ring,
tank, slacken the retaining clips, then
9 Slacken and remove the retaining nut and
sender unit and fuel tank marks are all
disconnect the vent pipes from the base of
bolts, then remove the two support rods from
correctly aligned.
the filler neck, and the main filler neck hose
the underside of the tank (see illustrations).
from the fuel tank. Where the original
10 Slowly lower the fuel tank out of position,
crimped-type Citroen hose clips are fitted, cut
disconnecting any other relevant vent pipes
6 Fuel tank - removal and refitting
the clips and discard them; use standard
as they become accessible (where
worm-drive hose clips on refitting.
necessary), and remove the tank from
7 Trace the fuel feed and return hoses back
underneath the vehicle.
Note: Refer to the warning note in Section 1
from the right-hand side of the tank to their
11 If the tank is contaminated with sediment
before proceeding.
union with the fuel pipes. Slacken the
or water, remove the sender unit (Section 5),
Removal
retaining clips and disconnect both hoses
and swill the tank out with clean fuel. The tank
is injection-moulded from a synthetic material
1 Before removing the fuel tank, all fuel must
from the fuel pipes, noting the point made
- if seriously damaged, it should be renewed.
be drained from the tank. Since a fuel tank
above about the crimped-type hose clips.
6.9a Fuel tank front left-hand retaining
6.9b Fuel tank support rod retaining
6.9c . . . and retaining bolt
bolt
n u t . . .

4A*6 Fuel and exhaust systems - carburettor engines
However, in certain cases, it may be possible
withdraw the cable from the bulkhead. When
Right-hand drive models
to have small leaks or minor damage repaired.
the end of the cable appears, untie the string
2 Unscrew the nut from the end of the pedal
Seek the advice of a specialist before
and leave it in position - it can then be used to
pivot shaft, whilst retaining the pivot shaft with
attempting to repair the fuel tank.
draw the cable back into position on refitting.
an open-ended spanner on the flats provided.
Refitting
Refitting
3 Pull the pedal and pivot shaft assembly
8 Tie the string to the end of the cable, then
from the support bracket.
12 Refitting is the reverse of the removal
use the string to draw the cable into position
4 Examine the pivot shaft for signs of wear or
procedure, noting the following points:
through the bulkhead. Once the cable end is
damage and, if necessary, renew it. The pivot
(a) When lifting the tank back into position,
visible, untie the string, then clip the outer
shaft is a screw fit in the pedal.
take care to ensure that none of the hoses
cable into its pedal bracket retainer, and clip
become trapped between the tank and
Left-hand drive models
the inner cable into position in the pedal end-
vehicle body.
9 Check that the cable is securely retained,
5 Slacken and remove the two nuts securing
(b) Ensure all pipes and hoses are correctly
then refit the felt undercover and driver's side
the pedal mounting bracket to the bulkhead.
routed, and securely held in position with
lower facia panel.
Slide off the outer part of the mounting clamp,
their retaining clips.
10 From within the engine compartment,
then withdraw the pedal from behind the
(c) Reconnect the handbrake cables and
ensure the outer cable is correctly seated in
facia, and slide off the inner part of the clamp.
adjust the handbrake as described in
the bulkhead grommet, then work along the
6 Examine the mounting bracket and pedal
Chapter 9.
cable, securing it in position with the retaining
pivot points for signs of wear, and renew as
(d) On completion, refill the tank with a small
clips and ties, and ensuring that the cable is
necessary.
amount of fuel, and check for signs of
correctly routed.
Refitting
leakage prior to taking the vehicle out on
11 Slide the flat washer onto the cable end,
the road.
and refit the spring clip.
7 Refitting is a reversal of the removal
12 Pass the outer cable through its
procedure, applying a little multi-purpose
carburettor mounting bracket grommet, and
grease to the pedal pivot point. On
7 Accelerator cable - removal,
reconnect the inner cable to the throttle cam.
completion, adjust the accelerator cable as
refitting and adjustment
Adjust the cable as described below.
described in Section 7.
Adjustment
Removal
13 Remove the spring clip from the
9 Choke cable - removal,
refitting and adjustment
1 Working in the engine compartment, free
accelerator outer cable. Ensuring that the
the accelerator inner cable from the
throttle cam is fully against its stop, gently pull
carburettor throttle cam, then pull the outer
the cable out of its grommet until all free play
Removal
cable out from its mounting bracket rubber
is removed from the inner cable.
1 Working in the engine compartment, free
grommet. Slide the flat washer off the end of
14 With the cable held in this position, refit
the choke inner cable from the carburettor
the cable, and remove the spring clip.
the spring clip to the last exposed outer cable
linkage, then slacken and remove the
2 Working back along the length of the cable,
groove in front of the rubber grommet and
retaining bolt and remove the outer cable
free it from any retaining clips or ties, noting
washer. When the clip is refitted and the outer
retaining clamp (see illustration).
cable is released, there should be only a small
its correct routing.
2 Slacken the retaining clip securing the
amount of free play in the inner cable (see
3 Working from inside the vehicle, release the
rubber collar to the outer cable, and slide the
illustration).
fasteners by rotating them through a quarter
collar off the cable. Where the original
15 Have an assistant depress the accelerator
of a turn anti-clockwise, and remove the
crimped-type Citroen hose clip is still fitted,
pedal, and check that the throttle cam opens
driver's side lower facia panel.
cut the clip and discard it; use a standard
fully and returns smoothly to its stop.
4 Release the retaining clips, and remove the
worm-drive hose clip on refitting.
felt undercover from underneath the driver's
3 Working back along the length of the cable,
8 Accelerator pedal -
side of the facia panel.
free it from any retaining clips or ties, noting
5 Release the retaining clip, and detach the
removal and refitting
its correct routing. Tie a length of string to the
inner cable from the top of the accelerator pedal.
end of the choke inner cable.
6 Release the outer cable from its retainer on
Removal
4 Working from inside the vehicle, pull the
the pedal mounting bracket, then tie a length
1 Disconnect the accelerator cable from the
choke lever fully out, to gain access to the
of string to the end of the cable.
pedal as described in paragraphs 3 to 5 of
retaining screw (see illustration). Slacken
7 Return to the engine compartment, and
Section 7.
and remove the retaining screw, then
7.14 Adjusting the accelerator cable
9.1 Undo the retaining bolt and remove
9.4 Choke lever retaining screw (arrowed)
the choke cable retaining clip

Fuel and exhaust systems - carburettor engines 4A*7
9.9 Choke cable-to-rubber collar retaining
clip (arrowed)
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
11.1 Sectional view of the Solex 32 PBISA carburettor fitted to 1124 cc models
appears through the lever aperture, untie the
1 Accelerator pump tube 4 Enrichment jet
7 Air correction jet
string and leave it in position in the vehicle - it
2 Idle ventilator 5 Main jet
8 Venturi
can then be used to draw the cable back into
3 Idle jet 6 Fuel econostat
position on refitting.
fully and returns smoothly to its stop. If
2 The throttle body contains a drilling through
Refitting
necessary, repeat the adjustment procedure.
which the engine coolant runs. The engine
5 Tie the string the end of the choke cable,
coolant warms the carburettor body quickly
then use the sting to draw the cable into
on cold starts, improving atomisation of the
position through the bulkhead into the engine
10 Unleaded petrol - general
fuel/air mixture and preventing carburettor
compartment. Once the cable end is fully in
information and usage
icing, during warm-up.
position, untie the string.
3 During slow running and at idle, fuel from
6 Reconnect the wiring connector (where
Note: The information given in tms Chapter is
the float chamber passes into the idle channel
fitted), and locate the choke lever in its facia
correct at the time of writing. If updated
through a metered idle jet. Here it is mixed
panel aperture. Refit the lever retaining screw,
information is thought to be required, check
with a small amount of air from a calibrated air
tightening it securely.
with a Citroen dealer. If travelling abroad,
bleed. The resulting mixture is drawn through
7 From within the engine compartment,
consult one of the motoring organisations (or a
a channel, to be discharged from the idle
ensure the outer cable is correctly seated in
similar authority) for advice on the fuel
orifice under the throttle valve. A tapered
the bulkhead grommet. Work along the cable,
available.
mixture screw is used to vary the outlet, and
securing it in position with all the relevant
1 The fuel recommended by Citroen is given
this ensures fine control of the idle mixture.
retaining clips and ties, and ensuring that the
in the Specifications Section of this Chapter,
4 A progression slot provides extra
cable is correctly routed.
followed by the equivalent petrol currently on
enrichment as it is uncovered by the opening
8 Slide the rubber collar and retaining clip
sale in the UK.
of the throttle valve during initial acceleration.
onto the end of the cable, then engage the
2 All Citroen ZX carburettor models are
5 Under normal operating conditions, fuel is
inner end of the cable with carburettor
designed to run on 95 octane petrol. Both
drawn through a calibrated main jet, into the
linkage. Align the rubber collar with the
leaded and unleaded petrol can be used
base of the auxiliary venturi. An emulsion tube
carburettor bracket, then refit the retaining
without modification. Super leaded (97 octane,
is placed in the auxiliary venturi, capped with
clip and securely tighten its retaining bolt.
UK "4-star") and super unleaded (98 octane)
an air correction jet. The fuel is mixed with air,
Adjust the cable as described below.
petrol can also be used if wished, though there
drawn in through the holes in the emulsion
is no advantage in doing so.
tube. The resulting mixture is discharged into
Adjustment
the main airstream via four orifices, spaced at
9 If not already done, slacken the retaining
90 apart, in the upper part of the auxiliary
clip securing the rubber collar to the outer
11 Carburettor -
venturi.
cable. Where the crimped-type Citroen hose
general information
6 The carburettor also has an accelerator
clip is still fitted, cut the clip and discard it;
pump, to provide an initial spurt of extra fuel
use a standard worm-drive hose clip on
during sudden acceleration. The accelerator
Solex 32 PBISA carburettor -
refitting (see illustration).
pump is controlled by a diaphragm, and is
1124 cc models
10 Ensuring that the choke lever is flush with
mechanically operated by a lever and rod
the facia panel and the carburettor linkage is
1 The Solex PBISA carburettor is a
which is connected to the throttle linkage.
fully against its stop, move the outer cable in
downdraught single-venturi instrument, with a
7 The idle speed is set by an adjustable
the rubber collar until the position is found
manually-controlled choke (see illustration).
screw. The adjustable mixture screw is sealed
where there is only a small amount of free play
The carburettor consists of three main
during production with a tamperproof plug, to
present in the inner cable. Hold the outer
components - the upper body, the main body,
prevent unnecessary or inexpert adjustment.
cable in this position, and securely tighten the
and the throttle body (which contains the
Solex 32-34 Z2 carburettor -
clip securing the rubber collar to the outer
throttle valve assembly). An insulating block
cable.
placed between the carburettor body and
1360 cc models
11 Have an assistant operate the choke
throttle body prevents excess heat transfer
8 The Solex 32-34 Z2 carburettor is a
lever, and check that the choke linkage closes
from the manifold to the main body.
downdraught progressive twin-venturi

4A*8 Fuel and exhaust systems - carburettor engines
pump is mechanically operated by a lever and
cam which is attached to the primary throttle
linkage. During acceleration, fuel is pumped
through a ball valve located in the pump
injector, and is discharged into both the
primary and secondary Venturis. The inlet ball
valve is located in a channel from the float
chamber; excess fuel/air mixture is returned to
the float chamber through a separate channel.
15 The idle speed is set by an adjustable
screw. The adjustable mixture screw is sealed
during production with a tamperproof plug, to
prevent unnecessary or inexpert adjustment.
12 Carburettor -
removal and refitting
Note: Refer to the warning note in Section 1
before proceeding. Where original crimped-
type Citroen hose clips are still fitted, the clips

11.8 Sectional view of the Solex 32-34 Z2 carburettor fitted to 1360 cc models
should be cut and discarded; obtain some
1 Idle jet
4 Secondary fuel jet
9 Primary main jet
standard worm-drive hose clips for refitting.
2 Primary air correction
5 Needle valve
10 Primary venturi
jet/emulsion tube
6 Bypass jet
Removal
3 Secondary air correction
7 Secondary venturi
1 Disconnect the battery negative terminal.
jet/emulsion tube
8 Secondary main jet
2 Remove the air cleaner-to-carburettor duct
as described in paragraphs 1 and 2 of Sec-
instrument (see illustration). The throttle
outlet, and this ensures fine control of the idle
tion 2.
linkages are arranged so that the secondary
mixture.
3 Free the accelerator inner cable from the
throttle valve will not start to open until the
11 On some models, an idle cut-off valve is
throttle cam, then pull the outer cable out
primary valve is about two-thirds open, but at
used to prevent run-on when the engine is
from its mounting bracket rubber grommet,
full throttle both valves are fully open. The
switched off. The valve uses a solenoid
along with its flat washer and spring clip.
choke control is manual.
plunger to block the idle jet when the ignition
4 Disconnect the choke inner cable from the
9 An electrical heating element is fitted to the
is switched off.
carburettor linkage, then undo the retaining
base of the throttle body. The heater warms
12 A progression slot provides extra
bolt and remove the retaining clamp. Position
the carburettor body quickly on cold starts,
enrichment as it is uncovered by the opening
the cable clear of the carburettor.
improving atomisation of the fuel/air mixture
of the throttle valve during initial acceleration.
5 On 1124 cc models, slacken the retaining
and preventing carburettor icing during warm-
13 Under normal operating conditions, the
clips and disconnect the coolant hoses from
up. The heater is fed directly from the ignition
amount of fuel discharged into the airstream
the base of the carburettor. Plug the hose
switch, and functions on the PTC (Positive
is controlled by a calibrated main jet. Fuel is
ends to minimise coolant loss, and mop up
Temperature Coefficient) principle; ie. as the
drawn through the main jet, into the base of a
any spilt coolant immediately.
heater temperature rises, so does its
vertical well which dips down into the fuel in
6 On 1360 cc models, disconnect the wiring
resistance.
the float chamber; an emulsion tube is placed
connector from the carburettor heating
10 During slow running and at idle, fuel from
in the well. The fuel is then mixed with air,
element and, where fitted, from the idle cut-off
the float chamber passes into the idle channel
drawn in through the air correction jet and
solenoid (see illustration).
through a metered idle jet. Here it is mixed
through the holes in the emulsion tube. The
7 Slacken the retaining clip, and disconnect
with a small amount of air from a calibrated air
resulting mixture is discharged from the main
the fuel feed hose from the carburettor. Place
bleed. The resulting mixture is drawn through
orifice through an auxiliary vent.
wads of rag around the union to catch any
a channel, to be discharged from the idle
14 The carburettor also has an accelerator
spilled fuel, and plug the hose as soon as it is
orifice under the primary throttle plate. A
pump to provide an initial spurt of extra fuel
disconnected, to minimise fuel loss (see
tapered mixture screw is used to vary the
during sudden acceleration. The accelerator
illustration).
12.6 Disconnecting the carburettor wiring
12.7 Carburettor fuel hose union -1360 cc
12.9 Carburettor retaining nuts (two of
connector -1360 cc models
models
four arrowed) -1360 cc models

Fuel and exhaust systems - carburettor engines 4A*9
8 Make a note of the correct fitted positions
of all the relevant vacuum pipes and breather
hoses, to ensure they are correctly positioned
on refitting, then release the retaining clips
(where fitted) and disconnect them from the
carburettor.
9 Unscrew the two (1124 cc models) or four
(1360 cc models) nuts and washers securing
the carburettor to the inlet manifold. Remove
13.22 Throttle valve
the carburettor assembly from the car (see
fast idle setting -
illustration). Remove the insulating spacer
Solex 32 PBISA
and/or gasket(s). Discard the gasket(s); new
carburettor
ones must be used on refitting. Plug the inlet
manifold port with a wad of clean cloth, to
Adjust screw Y until
prevent the possible entry of foreign matter.
clearance X is as given
in the Specifications
Refitting
10 Refitting is the reverse of the removal
procedure, noting the following points:
(a) Ensure the carburettor and inlet manifold
sealing faces are clean and flat. Fit a new
gasket, and securely tighten the
carburettor retaining nuts.

of its component parts before starting work;
carburettor main body and throttle body
(b) Use the notes made on dismantling to
note that most sealing washers, screws and
assemblies, and recover the insulating spacer.
ensure all hoses are refitted to their
gaskets are available in kits, as are some of
Examine the throttle valve spindle and throttle
original positions and, where necessary,
the major sub-assemblies. In most cases, it
bore for signs of wear or damage and, if
are securely held by their retaining clips.
will be sufficient to dismantle the carburettor
necessary, renew the throttle body assembly.
(c) Where the original crimped-type Citroen
and to clean the jets and passages.
14 Remove the idle mixture adjustment
hose clips were fitted, discard them; use
screw tamperproof cap. Screw the screw in
standard worm-drive hose clips when
Overhaul
until it seats lightly, counting the exacf number
refitting.
Note: Refer to the warning note in Section 1
of turns required to do this, then unscrew it.
(d) Refit and adjust the choke and
before proceeding.
On refitting, screw the screw in until it seats
accelerator cables as described in
4 Remove the carburettor from the vehicle as
lightly, then back the screw off by the number
Sections 7 and 9.
described in Section 12.
of turns noted on removal, to return the screw
(e) Refit the air cleaner duct as described in
5 Disconnect the vacuum hose from the
to its original position.
Section 2.
choke pull-down diaphragm.
15 Clean the jets, carburettor body
(f) On completion, check and, if necessary,
6 Disconnect the choke spring (where
assemblies, float chamber and internal
adjust the idle speed and mixture settings
necessary), then undo the six screws and lift
drillings. An air line may be used to clear the
as described in Chapter 1.
off the carburettor upper body.
internal passages once the carburettor is fully
7 Tap out the float pivot pin, and remove the
dismantled.
float assembly, needle valve, and float
Warning: If high pressure air is
13 Solex 32 PBISA carburettor
chamber gasket. Check that the needle valve
directed into drillings and
(1124 cc models) -
anti-vibration ball is free in the valve end, then
passages where a diaphragm is
examine the needle valve tip and seat for wear
fault finding, overhaul and
fitted, the diaphragm is likely to
or damage. Examine the float assembly and
adjustments
be damaged.
pivot pin for signs of wear and damage. The
float assembly must be renewed if it appears
Fault finding
to be leaking - shake the float to detect the
Aerosol cans of carburettor
cleaner are widely available,
1 If a carburettor fault is suspected, always
presence of fuel inside.
and can prove very useful in
check first that the ignition timing is correctly set,
8 Unscrew the fuel inlet union and inspect the
helping to clear internal
that the spark plugs are in good condition and
fuel filter. Clean the filter housing of debris
passages of stubborn
correctly gapped, that the accelerator and
and dirt, and renew the filter if it is blocked.
obstructions.
choke cables are correctly adjusted, and that
9 Undo the four screws, detach the
the air cleaner filter element is clean; refer to the
accelerator pump cover, and remove the
relevant Sections of Chapter 1, Chapter 5 or this
pump diaphragm and spring, noting which
16 Use a straight edge to check all
Chapter. If the engine is running very roughly,
way around they are fitted. Examine the
carburettor body assembly mating surfaces
first check the valve clearances as described in
diaphragm for signs of damage and
for distortion.
Chapter 1, then check the compression
deterioration, and renew if necessary.
17 On reassembly, renew any worn
pressures as described in Chapter 2.
10 Unscrew the idle jet from the main body.
components, and fit a complete set of new
2 If careful checking of all the above
11 Unscrew the main jet from the float
gaskets and seals. A jet kit and a gasket and
produces no improvement, the carburettor
chamber. Note that it may be necessary to
seal kit are available from your Citroen dealer.
must be removed for cleaning and overhaul.
remove a plug in the float chamber body, to
18 Reassembly is a reversal of the
3 Note that in the rare event of a complete
expose an opening through which the main jet
dismantling procedure. Ensure that all jets are
carburettor overhaul being necessary, it may
can be withdrawn.
securely locked in position, but take great
prove more economical to renew the
12 Remove the combined air correction jet
care not to overtighten them. Ensure all
carburettor as a complete unit. Check the
and emulsion tube from the auxiliary venturi.
mating surfaces are clean and dry, and that all
price and availability of a new carburettor and
13 Remove the two screws, separate the
body sections are correctly assembled with

4A*10 Fuel and exhaust systems - carburettor engines
13.25 Choke pull-down setting - Solex 32 PBISA carburettor
14.19 Throttle valve fast idle setting - Solex 32-34 Z2 carburettor
Adjust screw Y until clearance X is as given in the Specifications
Adjust screw Y u14ntil clearance X is as given in the Specifications
their fuel and air passages correctly aligned.
choke pull-down diaphragm, and apply a
expected, and cleaning does not improve the
Before refitting the carburettor to the vehicle,
vacuum to the diaphragm so that the
situation, the solenoid valve must be renewed.
set the throttle valve fast idle and choke pull-
diaphragm rod is pulled fully into the
4 Remove the five screws, and lift off the
down settings as described below.
diaphragm body. In the absence of a vacuum
carburettor upper body.
pump, the rod can be pushed into the
5 Tap out the float pivot pin, and remove the
Adjustments
diaphragm using a small screwdriver.
float assembly, needle valve, and float
Idle speed and mixture
25 With the rod fully retracted, use the shank
chamber gasket. Check that the needle valve
of a twist drill to measure the clearance
anti-vibration ball is free in the valve end, then
19 Refer to Chapter 1.
between the edge of the choke valve and
examine the needle valve tip and seat for wear
Float height setting
bore, and compare this to the clearance given
or damage. Examine the float assembly and
20 To accurately check the float height
in the Specifications (see illustration). If
pivot pin for signs of wear and damage. The
setting, a special float height checking gauge
necessary, remove the plug from the
float assembly must be renewed if it appears
is required. Therefore, this task must be
diaphragm cover, and adjust by turning the
to be leaking - shake the float to detect the
adjustment screw. Once the pull-down setting
entrusted to a Citroen dealer. As a guide, with
presence of fuel inside.
is correctly adjusted, refit the plug to the
the carburettor body inverted, so that the float
6 Unscrew the fuel inlet union and inspect the
diaphragm cover, and remove the vacuum
is at the top and the needle valve is
fuel filter. Clean the filter housing of debris
pump (where used).
depressed, the distance between the upper
and dirt, and renew the filter if it is blocked.
edge of the float and the sealing face of the
7 Undo the four screws, detach the
upper body (with its gasket fitted) should be
accelerator pump cover, and remove the
14 Solex 32-34 22 carburettor
approximately 38 mm. To adjust the float
pump diaphragm and spring, noting which
(1360 cc models) -
height setting, carefully bend the pivot arm.
way around they are fitted. Examine the
fault diagnosis, overhaul and
diaphragm for signs of damage and
Throttle valve fast idle setting
adjustments
deterioration, and renew if necessary.
21 Invert the carburettor, and operate the
Remove the choke pull-down diaphragm and
carburettor choke linkage to fully close the
part-load enrichment diaphragms, and
Fault finding
choke valve. The fast idle screw will butt
examine them in the same way.
1 Refer to Section 13.
against the fast idle cam, and force the
8 Unscrew the idle jet from the upper body.
throttle valve open slightly.
Overhaul
9 Unscrew both the primary and secondary
22 Using the shank of a twist drill, measure
Note: Refer to the warning note in Section 1
combined air correction jets and emulsion
the clearance between the edge of the throttle
before proceeding.
tubes.
valve and bore, and compare this to the
2 Remove the carburettor from the vehicle as
10 Using a long thin screwdriver, unscrew
clearance given in the Specifications. If
described in Section 12.
the main jets from the bottom of the emulsion
necessary, adjust by turning the fast idle
3 Unscrew the idle cut-off solenoid (where
tube drillings. Invert the carburettor, and catch
adjustment screw in the appropriate direction
fitted) from the carburettor body, and remove
the jets as they fall out of the drillings.
until the specified clearance is obtained (see
it along with its plunger and spring. To test the
11 Remove the idle mixture adjustment
illustration).
solenoid, connect a 12-volt battery to it
screw tamperproof cap. Screw the screw in
(positive terminal to the solenoid terminal,
until it seats lightly, counting the exact number
Choke pull-down setting
negative terminal to the solenoid body), and
of turns required to do this, then unscrew it.
23 Operate the carburettor choke linkage to
check that the plunger is retracted fully into
On refitting, screw the screw in until it seats
fully close the choke valve, and hold the
the body. Disconnect the battery, and check
lightly, then back the screw off by the number
linkage in this position.
that the plunger is pushed out by spring
of turns noted on removal, to return the screw
24 Attach a hand-held vacuum pump to the
pressure. If the valve does not perform as
to its original position.