1992 FORD SIERRA Fuel And Exhaust Systems Carburettor Workshop Manual

Fuel and exhaust systems - carburettor 4A•9
4A
13.4a Exploded view of Ford VV carburettor
A Throttle spindle
B Mixture screw
C By-pass leak adjuster
D Float
E Needle valve
F Main jet body
G Metering rod
H Air valve
J Automatic choke unit
K Bi-metal coil
L Carburettor control diaphragm
M Accelerator pump diaphragm
13.4b Exploded view of Weber 2V
carburettor - 1.6 models
A Top cover assembly
B Automatic choke assembly
C Automatic choke bi-metal housing
assembly
D Secondary idle jet
E Secondary throttle valve vacuum unit
F Idle speed screw
G Idle mixture screw
H Accelerator pump assembly
J Power valve diaphragm
K Float
L Primary emulsion tube
M Primary idle jet
N Needle valve
P Fuel filter
Q Secondary emulsion tube

4A•10Fuel and exhaust systems - carburettor
13.4c Exploded view of Weber 2V carburettor - 2.0 litre models up to 1985
A Top cover assembly
B Fuel filter
C Power valve assembly
D Float
E Needle Valve
F Gasket
G Main jet
H Main body assembly
J Primary idle jet assemblyK Accelerator pump diaphragm
L Accelerator pump gasket
M Automatic choke bi-metal housing
assembly
N Automatic choke assembly
P Vacuum pull-down diaphragm
assembly
Q Idle mixture screw
R Idle speed screwS Emulsion tube
T Accelerator pump jet
U Air correction jet
V Accelerator pump outlet check ball
valve assembly
W Low vacuum enrichment diaphragm
X Secondary idle jet and holder

Fuel and exhaust systems - carburettor 4A•11
4A
13.4d Exploded view of Weber 2V carburettor - 2.0 litre models from 1985
A Top cover assembly
B Automatic choke assembly
C Automatic choke bi-metal housing
D Secondary idle jet
E Secondary throttle valve vacuum unit
F Stepper motorG Idle mixture screw
H Accelerator pump assembly
J Power valve diaphragm
K Low vacuum enrichment diaphragm
L FloatM Primary emulsion tube
N Primary idle jet
P Needle valve
Q Fuel filter
R Secondary emulsion tube

4A•12Fuel and exhaust systems - carburettor
13.4e Exploded view of Pierburg 2V carburettor
A Automatic choke bi-metal housing
B O-ring
C Automatic choke coolant housing
D Automatic choke vacuum pull-down
unitE Secondary throttle valve vacuum unit
F Idle speed screw
G Accelerator pump diaphragm
H Power valve assembly
K Carburettor bodyL Fuel inlet pipe and filter
M Primary main jet
N Secondary main jet
O Top cover assembly
P Idle jet

Fuel and exhaust systems - carburettor 4A•13
4A
13.4f Exploded view of Weber 2V TLD carburettor
A Anti-dieselling valve
B Emulsion tubes
C Air correction jets
D Choke pull-down diaphragm assembly
E Choke linkage
F Needle valve
G Float
H Fast idle adjustment screw
J Idle speed adjustment screw
K Idle mixture adjustment screw
L Throttle valves
M Power valve assembly
N Accelerator pump assembly
P Low vacuum enrichment device
Q Throttle kicker
R Gasket
S Main jets
Note: A new gasket must be used when
refitting the carburettor. A tachometer and an
exhaust gas analyser will be required to check
the idle speed and mixture on completion.
Removal
1Disconnect the battery negative lead.
2Remove the air cleaner.
3Relieve the pressure in the cooling system
by unscrewing the expansion tank cap. If the
engine is warm, place a thick rag over the cap
and unscrew the cap slowly as a precaution
against scalding. Refit the cap after relieving
the pressure.4Identify the automatic choke coolant hose
locations, as an aid to refitting, then
disconnect the hoses (being prepared for
coolant spillage.) Either plug the hoses or
secure them with their ends facing upwards to
prevent loss of coolant.
5Disconnect the wiring from the anti-dieselling (anti-run-on) valve.
6Disconnect the fuel hose and vacuum pipe
(see illustration). Plug the end of the fuel
hose to minimise petrol spillage.
7Disconnect the throttle cable from the
carburettor throttle lever (see illustration).
8Remove the two securing nuts and
14Carburettor (Ford VV type) -
removal and refitting
14.7 Disconnecting the throttle cable from
the throttle lever - Ford VV carburettor14.6 Disconnecting the fuel hose - Ford VV
carburettor
Caution: Refer to the
precautions in Section 1 before
proceeding.

washers, and lift the carburettor from the inlet
manifold studs (see illustrations). Recover
the gasket.
Refitting
9Refitting is a reversal of removal, bearing in
mind the following points.
10Ensure that the mating faces of the inlet
manifold and carburettor are clean, and use a
new gasket.
11Ensure that the coolant hoses, fuel hose,
and vacuum pipe are correctly routed and free
from restrictions. If any of the hoses were
originally secured with crimped type clips,
discard these and use new worm drive clips
on refitting.
12On completion, check and if necessary
top-up the coolant level. Check and if
necessary adjust the idle speed and mixture.
Refer to Chapter 1, Sections 15 and 16.
1Proceed as described for the Ford VV
carburettor but note the following.
2On models with an electrically-heated
automatic choke, ignore all references to the
cooling system and coolant hoses.3Not all Weber carburettors are fitted with an
anti-dieselling valve.
4Disconnect all relevant wiring plugs and
vacuum pipes, if necessary noting their
locations for use when refitting.
5Disconnect the link arm from the throttle
linkage instead of disconnecting the throttle
cable.
6The carburettor is secured to the inlet
manifold by four nuts and washers.
Refer to Chapter 1, Sections 15 and 16.
1This procedure does not apply to models
fitted with a carburettor stepper motor, for
which no adjustment is possible.
2Check the idle speed and mixture. The idle
speed must be correct before attempting to
check or adjust the fast idle speed.
3With the engine at normal operating
temperature, and a tachometer connected in
accordance with the manufacturer’s
instructions, proceed as follows.
4Remove the air cleaner.
5Partially open the throttle, hold the choke
plate(s) fully closed, then release the throttle
so that on 1.6 litre models the fast idle
adjustment screw rests on the third (middle)
step of the fast idle cam (see illustration)and
on 2.0 litre models the fast idle adjustment
screw rests on the highest step of the fast idle
cam (see illustration).
6Release the choke plate(s), checking that
it/they remain(s) fully open; if not, the
automatic choke mechanism is faulty, or the
engine is not at normal operating temperature.
7Without touching the throttle pedal, start
the engine and check that the fast idle speed
is as specified. If adjustment is necessary,
turn the fast idle adjustment screw until the
correct speed is obtained.
8On completion of adjustment, stop the
engine and disconnect the tachometer, then
refit the air cleaner.1Proceed as described for the Ford VV
carburettor but note the following.
2The Pierburg carburettor is not fitted with
an anti-dieselling valve.
3Disconnect all relevant wiring plugs and
vacuum pipes, if necessary noting their
locations as an aid to refitting.
4Disconnect the throttle arm from the throttle
lever by removing the retaining clip instead of
disconnecting the cable (see illustration).
5The carburettor is secured to the inlet
manifold by three Torx type screws (see
illustration).
6On CVH models an insulator block is fitted
between the carburettor and the inlet manifold
in place of a gasket. There is no need to
renew the insulator block on refitting.
19Carburettor (Pierburg 2V
type) - removal and refitting
18Carburettor (Weber 2V type) -
fast idle speed adjustment
17Carburettor (Weber 2V type) -
idle speed and mixture adjustment16Carburettor (Weber 2V type) -
removal and refitting
15Carburettor (Ford VV type) - idle
speed and mixture adjustment
4A•14Fuel and exhaust systems - carburettor
14.8a Remove the securing nuts and
washers . . .
19.4 Throttle arm retaining clip (arrowed) -
Pierburg 2V carburettor
19.5 Removing the carburettor securing
screws (arrowed) - Pierburg 2V carburettor18.5b Fast idle speed adjustment - Weber
2V carburettor (2.0 litre models)
18.5a Fast idle speed adjustment - Weber
2V carburettor (1.6 litre models)
A Screw on third (middle) step of cam
B Fast idle screw
14.8b . . . and lift the carburettor from the
inlet manifold - Ford VV carburettor

Refer to Chapter 1, Sections 15 and 16.
1Check the idle speed and mixture
adjustment. The idle speed must be correct
before attempting to check or adjust the fast
idle speed.
2With the engine at normal operating
temperature, and a tachometer connected in
accordance with the manufacturer’s
instructions proceed as follows.
3Remove the air cleaner.
4Position the fast idle speed adjustment
screw on the lowest (6th) step of the fast idle
cam (see illustration).
5Check that the fast idle speed is as
specified. If adjustment is required, stop the
engine and proceed as follows.
6Remove the tamperproof cap from the fast
idle speed adjustment screw.
7Ensure that the adjustment screw is still
resting on the lowest step of the fast idle cam,
then open the throttle so that a small
screwdriver can be used to adjust the screw
from below the carburettor.
8Start the engine and recheck the fast idle
speed.
9If necessary, repeat the procedure given in
paragraphs 7 and 8 until the correct fast idle
speed is obtained.
10On completion of adjustment, stop the
engine and disconnect the tachometer, then
refit the tamperproof cap to the adjustment
screw, and refit the air cleaner.Note: A new gasket must be used when
refitting the carburettor. A tachometer and an
exhaust gas analyser will be required to check
the idle speed and mixture on completion.Removal
1Disconnect the battery negative lead.
2Remove the air cleaner.
3Disconnect the wiring from the anti-
dieselling (anti-run-on) valve.
4Disconnect the wiring from the automatic
choke heater.
5Disconnect the fuel supply and return
hoses, noting their locations to aid refitting.
Plug the ends of the hoses to minimise petrol
spillage.
6Disconnect the link arm from the throttle
linkage.
7Disconnect the vacuum pipe.
8Release the coolant hose from the bracket
under the automatic choke housing.
9Unscrew the four Torx screws, and lift the
carburettor from the inlet manifold. Recover
the gasket.
Refitting
11Refitting is a reversal of removal, bearing
in mind the following points.
12Ensure that the mating faces of the inlet
manifold and the carburettor are clean, and
use a new gasket.
13Ensure that all hoses, pipes and wiring are
correctly routed, and free from restrictions. If
any of the hoses were originally secured with
crimped-type clips, discard these, and use
new worm-drive clips on refitting.
14Make sure that the coolant hose is
correctly positioned in the bracket under the
automatic choke housing.
15On completion, check and if necessary
adjust the idle speed and mixture.
Refer to Chapter 1, Sections 15 and 16.1Proceed as described for the Weber 2V
carburettor, noting the following.
2The fast idle adjustment screw should be
positioned on the third (middle) step of the
fast idle cam (see illustration).
3Refer to the Specifications at the beginning
of this Chapter for the correct fast idle speed.
SOHC models
Removal
1Disconnect the battery negative lead.
2Partially drain the cooling system.
3Remove the air cleaner.
4Disconnect the coolant hoses from the
automatic choke (where applicable), and the
inlet manifold. Identify the hose locations for
use when refitting.
5Disconnect the fuel supply hose at the
carburettor and plug the end to minimise
petrol spillage.
6Disconnect all relevant wiring and vacuum
pipes from the carburettor, if necessary noting
the locations for use when refitting.
7Disconnect the throttle cable from the
throttle linkage.
8Disconnect the crankcase ventilation and
brake servo vacuum hoses from the inlet
manifold. The brake servo vacuum hose is
secured with a union nut (see illustrations).
9Disconnect any remaining wiring and
vacuum pipes from the inlet manifold, if
necessary noting the locations as an aid to
refitting.
10Where necessary, unbolt the throttle cable
bracket from the top of the inlet manifold for
improved access, and unbolt the dipstick tube
bracket.
11Unscrew the two nuts and four bolts
securing the manifold to the cylinder head,
noting the location of the rear engine lifting
25Inlet manifold - removal and
refitting
24Carburettor (Weber 2V TLD) -
fast idle speed adjustment
23Carburettor (Weber 2V TLD) -
idle speed and mixture adjustment
22Carburettor (Weber 2V TLD) -
removal and refitting
21Carburettor (Pierburg 2V type)
- fast idle speed adjustment
20Carburettor (Pierburg 2V type) -
idle speed and mixture adjustment
Fuel and exhaust systems - carburettor 4A•15
4A
25.8a Disconnecting the crankcase
ventilation . . .
24.2 Fast idle speed adjustment - Weber
2V TLD carburettor
A Fast idle cam
B Adjustment screw on middle step of cam21.4 Fast idle speed adjustment - Pierburg
2V carburettor
Screw (arrowed) should rest on lowest (6th)
step of cam
Caution: Refer to the
precautions in Section 1 before
proceeding.

bracket (see illustration).
12Lift the inlet manifold from the cylinder
head, and recover the gasket (see
illustration).
13If desired, the carburettor can be removed
from the inlet manifold by unscrewing the
securing nuts or screws. Refer to the relevant
Section describing carburettor removal and
refitting. Recover the gasket.
Refitting
14Refitting is a reversal of removal bearing
in mind the following points.
15Ensure that all mating faces are clean.
16Renew the gasket(s), and apply a bead of
sealant at least 5.0 mm (0.2 in) wide around
the central coolant aperture on both sides of
the manifold-to-cylinder head gasket.
17Tighten the manifold securing nuts and
bolts progressively to the specified torque,
ensuring that the engine lifting bracket is in
place.
18Make sure that all hoses, pipes and wires
are correctly reconnected, and if the fuel
supply hose was originally secured with a
crimped type clip, discard this and use a new
worm drive clip on refitting.
19On completion, refill the cooling system,
adjust the throttle cable and check and if
necessary adjust the idle speed and mixture.
DOHC models
Removal
20Disconnect the battery negative lead.
21Partially drain the cooling system.
22Remove the air cleaner.
23Disconnect the coolant hoses from the
thermostat housing and the inlet manifold,
noting their locations to assist with refitting.
24Disconnect the fuel supply and return
hoses from the carburettor. Plug their ends to
minimise petrol spillage.
25Release the coolant hose from the bracket
under the automatic choke housing.
26Disconnect the HT leads from the spark
plugs, and move them to one side.
27Disconnect all relevant wiring and vacuum
pipes from the carburettor, thermostat
housing and inlet manifold, noting the
locations as an aid to refitting.
28Disconnect the crankcase breather hose
from the inlet manifold. 29Disconnect the throttle cable from the
throttle linkage.
30Make a final check to ensure that all
relevant wires, pipes and hoses have been
disconnected to facilitate removal of the
manifold.
31Unscrew the ten bolts and two nuts
securing the manifold to the cylinder head.
32Lift the manifold clear of the cylinder
head. Recover the gasket.
33Recover the two plastic spark plug
spacers from the recesses in the cylinder
head.
34If desired, the carburettor can be removed
from the manifold by unscrewing the securing
screws. Refer to the carburettor removal and
refitting Sections as necessary.
Refitting
35Refitting is a reversal of removal, bearing
in mind the following points.
36Ensure that all mating faces are clean.
37Ensure that the spark plug spacers are in
position in the cylinder head recesses before
refitting the manifold.
38Renew all gaskets.
39Tighten all manifold securing nuts and
bolts progressively to the specified torque.
40Make sure that all hoses, pipes and wires
are securely reconnected in their original
positions.
41On completion, refill the cooling system.
Check the adjustment of the throttle cable.
Check, and if necessary adjust, the idle speed
and mixture.
CVH models
Removal
42Proceed as described in paragraphs 1 to
3 inclusive.
43Disconnect the coolant hoses from the
automatic choke, thermostat housing and
inlet manifold, noting their locations for use
when refitting.
44Disconnect the fuel supply hose at the
carburettor and plug the end to minimise
petrol spillage.
45Disconnect all relevant wiring and vacuum
pipes from the carburettor, thermostat
housing and inlet manifold, noting the
locations as an aid to refitting.
46Disconnect the throttle cable from the
throttle linkage.
47Unbolt the dipstick tube from the inlet
manifold and withdraw the dipstick and
dipstick tube from the cylinder block.
48Unscrew the seven nuts securing the
manifold to the cylinder head, then lift the
manifold from the cylinder head, and recover
the gasket.
49If desired, the carburettor can be removed
from the manifold by removing the securing
screws. Recover the insulator block (see
illustrations).
50The carburettor intermediate plate can be
removed from the manifold by unscrewing the
three securing screws. Recover the gasket.
51If necessary, the thermostat and housing
can be removed from the manifold.
4A•16Fuel and exhaust systems - carburettor
25.8b . . . and brake servo vacuum hoses
from the inlet manifold - SOHC models25.12 Lifting the inlet manifold from the
cylinder head - SOHC models
25.49b . . . and the insulator block from the
inlet manifold - CVH models25.49a Removing the carburettor . . .
25.11 Rear engine lifting bracket location -
SOHC models