warning FORD SIERRA 1987 2.G Fuel And Exhaust Systems Carburettor Workshop Manual

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.