Rover 214 & 414 Service and Repair Manual - Rover club

3.8 Disconnecting multiplug from purge
valve
A Hose securing clip
8 Disconnect the multiplug from the purge
valve (see illustration).
9 Release the securing clip and disconnect
the hose from the purge valve.
10 Note 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.
11 Release the securing strap and remove
the canister/purge valve assembly.
12 Refitting 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
13 Disconnect the battery negative terminal
then disconnect the wiring connector from the
purge valve (see illustration).
14 Release the retaining clips and disconnect
the inlet and outlet hoses from the valve.
15 Prise 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.
16 Undo the bolt securing the purge valve to
its mounting bracket and remove the valve
from the vehicle.
17 Refitting is a reverse of the removal
procedure. Use a new inlet hose adaptor Oring.
Purge valve (on charcoal canister) -
renewal
18 Disconnect the battery negative lead.
19 Disconnect the multiplug from the purge
valve.
20 Release the securing clip and disconnect
the hose from the purge valve.
21 Pull the valve from its location on the
canister and discard its O-ring (see
illustration).
22 Refitting 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.
3.13 Purge valve assembly
1 Wiring connector
2 Inlet hose -
charcoal canister
to purge valve
3 Outlet hose -
purge valve to
throttle housing
4 C-clip
5 Inlet hose
connector
6 O-ring
7 Purge valve
Exhaust emission control
23 If 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
24 The performance of the catalytic
converter can be checked only by using a
good-quality, carefully-calibrated exhaust gas
analyser.
25 Check 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.
26 Once 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 the
1689 Rover 214 & 414 Updated Version 09/97
Emission control systems 4D•3
3.21 Renew purge valve O-ring (arrowed)
level at the gas-sampling pipe (below 0.5 %
approximately on fuel-injected engines,
slightly higher on carburettor engines).
27 If 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
28 The performance of the catalytic
converter can be checked only by using a
good-quality, carefully-calibrated exhaust gas
analyser.
29 Where 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.
30 If 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
31 Refer to Section 18 in Part A of this
Chapter.
Lambda (oxygen) sensor - operational
check
32 The 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.
4D