Land Rover Rover 214 Repair 1689 04d Rover Manual

							1689 Rover 214 & 414 Updated Version 09/97
4D
Chapter 4 Part D
Emission control systems
Catalytic converters - general information and precautions  . . . . . . . 2
Emission control system components - testing and renewal  . . . . . . 3General information  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
4D•1
Contents
Specifications
Torque wrench settingsNm lbf ft
Lambda sensor  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 41
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced  DIY
mechanicVery difficult,
suitable for expert DIY
or  professional
Degrees of difficulty
54321
1 General information
Apart from their ability to use unleaded
petrol and the various features which help to
minimise emissions and are built into the fuel
system, all models have at least the
crankcase emission-control system described
below. Models equipped with a catalytic
converter are also fitted with the exhaust and
evaporative emission control system.
Crankcase emission control
To reduce the emission of unburned
hydrocarbons from the crankcase into the
atmosphere, the engine is sealed and the
blow-by gases and oil vapour are drawn fromthe crankcase, through a wire mesh oil
separator in the cylinder head cover, into the
inlet tract to be burned by the engine during
normal combustion. On carburettor engines, a
single breather hose connects the cylinder
head cover to the carburettor continuous-
depression area. On fuel-injected engines, a
small-bore breather hose connects the
cylinder head cover to the throttle body
downstream of the throttle disc, while a
larger-bore hose is connected above the
throttle disc so that the same effect is
obtained at all states of manifold depression.
Under conditions of high manifold
depression (idling, deceleration), the gases
will be sucked positively out of the crankcase.
Under conditions of low manifold depression
(acceleration, full-throttle running), the gases
are forced out of the crankcase by the
(relatively) higher crankcase pressure. If theengine is worn, the raised crankcase pressure
(due to increased blow-by) will cause some of
the flow to return under all manifold
conditions.
Evaporative emission control
To minimise the escape into the
atmosphere of unburned hydrocarbons, an
evaporative emissions control system is fitted
to models equipped with a catalytic converter.
The fuel tank filler cap is sealed and a
charcoal canister is mounted in the engine
compartment to collect the petrol vapours
generated in the tank when the vehicle is
parked. It stores them until they can be
cleared from the canister (under the control of
the fuel-injection/ignition system ECU via the
purge control valve) into the inlet tract to be
burned by the engine during normal
combustion. 
						

							To ensure that the engine runs correctly
when it is cold and/or idling and to protect the
catalytic converter from the effects of an over-
rich mixture, the purge control valve is not
opened by the ECU until the engine has
warmed up to above 70°C, the engine speed
exceeds 1500 rpm and manifold absolute
pressure is below 30 kPa. The valve solenoid
is then modulated on and off to allow the
stored vapour to pass into the inlet tract.
Exhaust emission control
To minimise the amount of pollutants which
escape into the atmosphere, some models
are fitted with a catalytic converter in the
exhaust system. Either an open-loop control
system, which has no feedback from the
converter to the fuel system, or a closed-loop
control system, in which the lambda sensor in
the exhaust system provides the fuel-
injection/ignition system ECU with constant
feedback (which enables it to adjust the
mixture to provide the best possible
conditions for the converter to operate) may
be fitted.
If a lambda sensor is fitted, it has a heating
element built-in that is controlled by the ECU
through the lambda sensor relay to quickly
bring the sensor’s tip to an efficient operating
temperature. The sensor’s tip is sensitive to
oxygen and sends the ECU a varying voltage
depending on the amount of oxygen in the
exhaust gases. If the intake air/fuel mixture is
too rich, the exhaust gases are low in oxygen
so the sensor sends a low-voltage signal, the
voltage rises as the mixture weakens and the
amount of oxygen rises in the exhaust gases.
Peak conversion efficiency of all major
pollutants occurs if the intake air/fuel mixture
is maintained at the chemically-correct ratio
for the complete combustion of petrol of 
14.7 parts (by weight) of air to 1 part of fuel
(the stoichiometric ratio). The sensor output
voltage alters in a large step at this point, the
ECU using the signal change as a reference
point and correcting the intake air/fuel mixture
accordingly by altering the fuel injector pulse
width.
2 Catalytic converters- general
information and precautions
The catalytic converter is a reliable and
simple device which needs no maintenance in
itself but there are some facts of which an
owner should be aware if the converter is to
function properly for its full service life.
a) DO NOT use leaded petrol in a vehicle
equipped with a catalytic converter.
b) Always keep the ignition and fuel systems
well-maintained in accordance with the
manufacturer’s schedule.
c) If the engine develops a misfire, do not
drive the vehicle at all (or at least as little
as possible) until the fault is cured.d) DO NOT push-start or tow-start the
vehicle.
e) DO NOT switch off the ignition at high
engine speeds.
f) DO NOT use fuel or engine oil additives.
g) DO NOT continue to use the vehicle if the
engine burns oil to the extent of leaving a
visible trail of blue smoke.
h) Remember that the catalytic converter
operates at very high temperatures, hence
the heat shields on the vehicle’s
underbody, and the casing will become
hot enough to ignite combustible
materials which brush against it. DO NOT,
therefore, park the vehicle in dry
undergrowth, over long grass or piles of
dead leaves.
i) Remember that the catalytic converter is
FRAGILE. DO NOT strike it with tools
during servicing work, take great care
when working on the exhaust system,
ensure that the converter is well clear of
any jacks or other lifting gear used to raise
the vehicle and do not drive the vehicle
over rough ground, road humps, etc. in
such a way as to ground the exhaust
system.
j) In some cases, particularly when the
vehicle is new and/or is used for stop/start
driving, a sulphurous smell (like that of
rotten eggs) may be noticed from the
exhaust. Once the vehicle has covered a
few thousand miles the problem should
disappear. In the meantime, a change of
driving style or of the brand of petrol used
may effect a solution.
k) The catalytic converter, used on a well-
maintained and well-driven vehicle,
should last for between 50 000 and
100 000 miles.
3 Emission control system
components- testing and
renewal
5
Crankcase emission control
1The components of this system require no
attention other than to check that all hosesare clear and that the wire mesh oil separators
are flushed clean with a suitable solvent
whenever the cylinder head cover is removed
(see illustration).
Evaporative emission control
Testing
2If the system is thought to be faulty,
disconnect the hoses from the charcoal
canister and purge control valve and check
that they are clear by blowing through them. If
the purge control valve or charcoal canister
are thought to be faulty, they must be
renewed. Note that the purge control valve
may either be separate from, or mounted on
top of, the charcoal canister. 
Charcoal canister (purge valve
separate) - renewal
3Disconnect the battery negative lead.
4Note the fitted positions of the canister
hoses, then use a suitable pair of pliers to
release the retaining clips (where fitted) and
disconnect all the hoses from the canister
(see illustration).
5Lift the canister up to free it from its
mounting bracket then remove it from the
engine compartment.
6Refitting is the reverse of the removal
procedure. Ensure that all hoses are correctly
refitted and, where necessary, securely held
by their retaining clips.
Charcoal canister/purge valve
assembly - renewal
7Disconnect the battery negative lead.
4D•2 Emission control systems
3.4  Charcoal canister hose connections
1 Vacuum hose
2 Outlet hose - canister to purge valve
3 Inlet hose - fuel tank to canister
4 Charcoal canister
5 Drain hose
3.1  Clean oil separators whenever cylinder
head cover is removed
1689 Rover 214 & 414 Updated Version 09/97 
						

							8Disconnect the multiplug from the purge
valve (see illustration).
9Release the securing clip and disconnect
the hose from the purge valve. 
10Note the fitted positions of the canister
fuel and vent hoses, then use a suitable pair of
pliers to release the retaining clips (where
fitted) and disconnect both hoses from the
canister.
11Release the securing strap and remove
the canister/purge valve assembly.
12Refitting is the reverse of the removal
procedure. Ensure that all hoses are correctly
refitted and, where necessary, securely held
by their retaining clips.
Purge valve (charcoal canister
separate)  - renewal
13Disconnect the battery negative terminal
then disconnect the wiring connector from the
purge valve (see illustration).
14Release the retaining clips and disconnect
the inlet and outlet hoses from the valve.
15Prise out the C-clip which secures the
inlet hose adaptor to the mounting bracket,
then withdraw the adaptor, noting the O-ring
which is fitted between the adaptor and purge
valve. Discard the O-ring which must be
renewed.
16Undo the bolt securing the purge valve to
its mounting bracket and remove the valve
from the vehicle.
17Refitting is a reverse of the removal
procedure. Use a new inlet hose adaptor O-
ring.
Purge valve (on charcoal canister)  -
renewal
18Disconnect the battery negative lead.
19Disconnect the multiplug from the purge
valve.
20Release the securing clip and disconnect
the hose from the purge valve. 
21Pull the valve from its location on the
canister and discard its O-ring (see
illustration).
22Refitting the valve is the reverse of the
removal procedure, noting the following:
a) Thoroughly clean the mating surfaces.
b) Fit a new O-ring to the valve. 
c) Ensure all connections are secure.
Exhaust emission control
23If the CO level reading is too high (or if any
other symptom is encountered which causes
you to suspect a fault in the exhaust emission
control system), always check first that the air
cleaner filter element is clean, the spark plugs
are in good condition and correctly gapped,
that the engine breather and vacuum hoses
are clear and undamaged, and that the
accelerator cable is correctly adjusted. If the
engine is running very roughly, check its
compression pressures, bearing in mind the
possibility that one of the hydraulic tappets
might be faulty, producing an incorrect valve
clearance. Check also that all wiring is in good
condition, with securely-fastened connectors,
that the fuel filter (fuel-injected engines only)
has been renewed at the recommended
intervals and that the exhaust system is
entirely free of air leaks which might upset the
operation of the catalytic converter. Only
when all these have been checked and found
to be in serviceable condition should the
converter be suspected.
Testing - open-loop system
24The performance of the catalytic
converter can be checked only by using a
good-quality, carefully-calibrated exhaust gas
analyser.
25Check that the CO level is as specified at
the gas-sampling pipe when the engine is fully
warmed-up to normal operating temperature.
If not, check the fuel and ignition systems until
the fault is found and the level is restored to
its correct value.
26Once the CO level is known to be correct
upstream of the catalytic converter, take the
vehicle on a brisk 4-mile road test and check
the CO level at the tailpipe immediately on
return. It should be significantly lower than thelevel at the gas-sampling pipe (below 0.5 %
approximately on fuel-injected engines,
slightly higher on carburettor engines).
27If the tailpipe CO level is little different
from that at the gas-sampling pipe, repeat the
check ensuring that it is made immediately on
return from road test or the converter may not
be at normal operating temperature and will
not have reached its peak conversion
efficiency. If the results are the same, the
catalytic converter is proven faulty and must
be renewed.
Testing - closed-loop system
28The performance of the catalytic
converter can be checked only by using a
good-quality, carefully-calibrated exhaust gas
analyser.
29Where a gas-sampling pipe is fitted, the
test described above can be carried out. If the
CO level at the tailpipe is little different from
that at the gas-sampling pipe, the catalytic
converter is probably faulty and must be
renewed, once the fuel-injection and ignition
systems have been checked thoroughly using
Rover diagnostic equipment and are known to
be free from faults.
30If a gas-sampling pipe is not fitted and the
CO level at the tailpipe is too high, the
complete fuel-injection and ignition systems
must be checked thoroughly by using Rover
diagnostic equipment. Once these have been
checked and are known to be free from faults,
the fault must be in the catalytic converter,
which must be renewed.
Catalytic converter - renewal
31Refer to Section 18 in Part A of this
Chapter.
Lambda (oxygen) sensor - operational
check
32The manufacturer’s maintenance
schedule calls for regular checks of the
lambda sensor’s operation. This can be done
only by attaching Rover diagnostic equipment
to the sensor wiring and checking that the
voltage varies from low to high values when
the engine is running. Do not attempt to test
any part of the system with anything other
than the correct test equipment.
Emission control systems  4D•3
3.21  Renew purge valve O-ring (arrowed)
3.13  Purge valve assembly
1 Wiring connector
2 Inlet hose -
charcoal canister
to purge valve
3 Outlet hose -
purge valve to
throttle housing4 C-clip
5 Inlet hose
connector
6 O-ring
7 Purge valve
3.8  Disconnecting multiplug from purge
valve
A  Hose securing clip
4D
1689 Rover 214 & 414 Updated Version 09/97 
						

							Lambda sensor - renewal
33Note that the lambda sensor is delicate
and will not work if it is dropped or knocked, if
its power supply is disrupted, or if any
cleaning materials are used on it.
34Disconnect the battery earth lead.
35Release the sensor’s wiring connector
from the bracket on the gearbox and unplug it
to disconnect the sensor (see illustration).
36Raising and supporting the front of the
vehicle, if required, to remove the sensor fromunderneath, unscrew the sensor from the
exhaust system front pipe. Retain its sealing
washer.
37On refitting, clean the sealing washer and
renew it if it is damaged or worn, then refit the
sensor, tightening it to its specified torque
wrench setting. Reconnect the wiring and refit
the connector plug.
Lambda sensor relay - general
38Refer to Chapter 12.
4D•4 Emission control systems
3.35  Lambda sensor viewed from above
1689 Rover 214 & 414 Updated Version 09/97