1990 FORD SIERRA air conditioning

2.0 litre DOHC models
Inlet manifold nuts and bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 to 2415 to 18
Exhaust manifold nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 to 2515 to 18
Carburettor bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 to 106 to 7
General information
The fuel system on carburettor models
may comprise a fuel tank, a fuel pump, a fuel
pressure regulator and/or vapour separator, a
downdraught carburettor and a
thermostatically-controlled air cleaner.
On Saloon, Hatchback and Estate models,
the fuel tank is mounted under the rear of the
vehicle, on the right-hand side. On P100
models, the fuel tank is mounted behind the
cab, between the chassis frame and the load
area. The tank is ventilated, and has a simple
filler pipe and a fuel gauge sender unit.
The mechanical fuel pump is a diaphragm
type, actuated by a pushrod bearing on an
eccentric cam on the auxiliary shaft on SOHC
models, or on the camshaft on CVH models.
DOHC models and models with air
conditioning have an electric fuel pump
mounted under the rear of the vehicle, next to
the fuel tank. DOHC models have a combined
pump and fuel level sender unit.
The fuel pressure regulator and/or vapour
separator is used to stabilise the fuel supply
to the carburettor. The pressure regulator
provides a constant fuel pressure, and hence
maintains a constant float level in the
carburettor which reduces exhaust emission
levels. The vapour separator purges vapour
from the carburettor fuel supply, thus
improving hot starting qualities. All models up
to 1985 are fitted with a fuel pressure
regulator. All models from 1985 except 2.0
litre SOHC models and CVH models are fitted
with a combined fuel pressure regu-
lator/vapour separator. 2.0 litre models from
1985 and CVH models are fitted with a vapour
separator only. DOHC models have no
pressure regulator or vapour separator fitted.
The carburettor may be either a Ford
variable venturi (VV) type, a Weber twin venturi
(2V or 2V TLD) type, or a Pierburg twin venturi
(2V) type, depending on model. Each type ofcarburettor is available in several versions to
suit particular engine and equipment
combinations.
The air cleaner has a vacuum or waxstat
controlled air inlet supplying a blend of hot
and cold air to suit the prevailing engine
operating conditions.
Precautions
Tamperproof adjustment screws -
caution
Certain adjustment points in the fuel system
(and elsewhere) are protected by
“tamperproof” caps, plugs or seals. The
purpose of such tamperproofing is to
discourage, and to detent, adjustment by
unqualified operators.
In some EEC countries (though not yet in the
UK) it is an offence to drive a vehicle with
missing or broken tamperproof seals. Before
disturbing a tamperproof seal, satisfy yourself
that you will not be breaking local or national
anti-pollution regulations by doing so. Fit a
new seal when adjustment is complete when
this is required by law.
Do not break tamperproof seals on a vehicle
which is still under warranty.
Work proceedures
When working on fuel system components,
scrupulous cleanliness must be observed,
and care must be taken not to introduce any
foreign matter into fuel lines or components.
Carburettors in particular are delicateinstruments, and care should be taken not to
disturb any components unnecessarily.
Before attempting work on a carburettor,
ensure that the relevant spares are available.
Full overhaul procedures for carburettors have
not been given in this Chapter, as complete
strip-down of a carburettor is unlikely to cure
a fault which is not immediately obvious,
without introducing new problems. If
persistent problems are encountered, it is
recommended that the advice of a Ford dealer
or carburettor specialist is sought. Most
dealers will be able to provide carburettor re-
jetting and servicing facilities, and if necessary
it should be possible to purchase a
reconditioned carburettor of the relevant type.
Refer to Chapter 1, Section 38.
Removal
1On CVH models, disconnect the battery
negative lead.
2Remove the screws from the top of the air
cleaner cover (see illustration).
3Disconnect the cold air inlet hose from the
air cleaner spout or the inlet on the front body
panel. The hose is secured by toggle clips
(see illustration).
4Disconnect the hot air inlet hose from the
air cleaner spout or the hot air shroud on the
exhaust manifold (see illustration).
5Disconnect the vacuum hose from the inlet
manifold (see illustration).
6On DOHC models, disconnect the
camshaft cover breather hose
7Where applicable, on OHC models remove
the screw securing the air cleaner body to the
camshaft cover.
8Withdraw the air cleaner, and on CVH
models, disconnect the wiring plug from the
3Air cleaner - removal and
refitting
2Air cleaner element - renewal
1General information and
precautions
4A•4Fuel and exhaust systems - carburettor
3.4 Hot air intake hose on hot air shroud3.3 Disconnecting the cold air intake hose
from the air cleaner spout3.2 Air cleaner securing screws (arrowed)
Warning - Fuel - Many of the
procedures given in this
Chapter involve the
disconnection of fuel pipes and
system components which may result in
some fuel spillage. Before carrying out
any operation on the fuel system, refer to
the precautions given in the “Safety first”
Section at the beginning of this manual
and follow them implicitly. Petrol Is a
highly dangerous and volatile substance,
and the precautions necessary when
handling it cannot be over stressed.

5On some early pumps, the top cover can be
removed for access to the filter. Removing the
pump and cleaning the filter may cure the
problem. On models with a sealed pump, or
where cleaning the interior of the pump and
filter does not solve the problem, the pump
should be renewed, as no spares are
available. Check that there is petrol in the fuel
tank before condemning the pump!
6On completion of the test, reconnect the
outlet hose to the pump. If the hose was
originally secured with a crimped type clip,
discard this and use a new worm drive clip.
Reconnect the coil LT lead.
Electric pump
SOHC and CVH models with air
conditioning
7The fuel pump is located under the rear of
the vehicle, next to the fuel tank (see
illustration).
8If the pump is functioning, it should be
possible to hear it “buzzing” by listening
under the rear of the vehicle when the ignition
is switched on.
9If the pump appears to have failed
completely, check the fuse and relay.
10To test the pump, disconnect the fuel
supply hose from the pressure regulator or
vapour separator (as applicable) in the engine
compartment. Lead the hose into a measuring
cylinder.
11Take appropriate fire precautions, then
switch on the ignition for 30 seconds (do notstart the engine), and measure the quantity of
petrol delivered: it should be at least 400 ml
(0.7 pint). If not, the pump is faulty and should
be renewed, as no spares are available.
12On completion of the test, reconnect the
hose to the pressure regulator or vapour
separator, as applicable, and if the hose was
originally secured with a crimped type clip,
discard this and fit a new worm drive clip.
2.0 litre DOHC models
13If the fuel pump is functioning, it should
be possible to hear it “buzzing” by listening
under the rear of the vehicle when the ignition
is switched on. Unless the engine is started,
the fuel pump should switch off after
approximately one second.
14If the pump appears to have failed
completely, check the appropriate fuse and
relay, and where applicable check the state of
the fuel pump inertia cut-off switch as follows.
15The inertia cut-off switch is located in the
spare wheel well. The switch incorporates a
reset button, which should normally be in the
depressed position. Check the position of the
reset button before assuming that a fault
exists in the fuel pump.
16To test the fuel pump, special equipment
is required, and it is recommended that any
suspected faults are referred to a Ford dealer.
Mechanical pump
Note: A new gasket must be used when
refitting the pump.
1Disconnect the battery negative lead.
2For improved access on CVH models,
remove the air cleaner.
3Identify the hose locations as an aid to
refitting, then disconnect the hoses from the
pump and plug them.
4Remove the two securing bolts and
withdraw the pump from the cylinder block or
cylinder head, as applicable (see illustration).
5Recover the gasket, and if desired remove
the operating pushrod (see illustration).6Clean the exterior of the pump with paraffin
and wipe dry. Clean all traces of gasket from
the pump flange and the cylinder block or
cylinder head, as applicable.
7On early pumps with a removable top
cover, remove the securing screw and
withdraw the cover and the nylon mesh filter
with seal (see illustration). Clean the filter,
the cover and the pump with petrol. Locate
the filter in the cover and fit the cover to the
pump, so that the indentations on the cover
and pump are aligned. Tighten the cover
securing screw.
8Refitting is a reversal of removal, but fit a
new gasket, and tighten the securing bolts to
the specified torque. Ensure that the hoses
are correctly connected, and if the hoses were
originally secured with crimped type clips,
discard these and use new worm drive clips.
Electric pump
SOHC and CVH models with air
conditioning
9Disconnect the battery negative lead.
10Chock the front wheels, then jack up the
rear of the vehicle and support on axle stands.
(see “Jacking and Vehicle Support”).
11Clean the area around the pump
mounting, and position a suitable container
under the pump.
12Using a hose clamping tool or self-locking
pliers, clamp the fuel tank-to pump hose to
prevent excessive petrol spillage, or
alternatively make arrangements to collect the
contents of the fuel tank which will otherwise
be released. Disconnect the hose from the
pump.
13Disconnect the fuel outlet hose from the
pump and plug the hose to prevent petrol
spillage.
14Disconnect the wiring plug from the
pump.
15Slacken the clamping bolt, and slide the
pump from the bracket assembly.
16Refitting is a reversal of removal, but
make sure that the rubber sleeve is correctly
located around the pump body in the bracket,
and ensure that the fuel hoses are securely
8Fuel pump - removal and
refitting
4A•6Fuel and exhaust systems - carburettor
7.7 Electric fuel pump - SOHC and CVH
models with air conditioning
A Clamping bracket
B Fuel inletC Fuel outlet
D Wiring plug
8.5 Withdrawing the fuel pump operating
pushrod - CVH model8.4 Withdrawing the fuel pump from the
cylinder head - CVH model8.7 Removing the top cover from an early
type fuel pump for access to the mesh
filter
Caution: Refer to the
precautions in Section 1 before
proceeding.
Caution:Petrol under pressure
may spray out of the outlet as
the hose is disconnected.