Range Rover Classic. Manual — part 42
MFI
1
FAULT DIAGNOSIS
ENGINE TUNING
Circuit fault diagnosis may be carried out on all V8i
vehicles, using Testbook. Testbook will guide the
operator by visual prompts through a series of
diagnostic checks.
Before commencing any fault diagnosis, the following
preminary checks must be carried out.
Preliminary checks
CAUTION: Catalyst exhaust: If engine is
misfiring or fails to start within 12 seconds
the cause must be rectified. Failure to do
so will result in irreparable damage to the
catalysts. After rectification the engine must be
run at 1500 rev/min (no load) for 3 minutes to
purge any accumulation of fuel in the system.
1. Check that the inertia fuel shut off switch is not
tripped.
2. Check fuse in main fuse panel.
3. Check for ample fuel in tank.
4. Check air inlet system for possible leaks into the
intake manifold.
5. Check HT cables for correct firing order and
routing.
6. Check ignition timing.
Only when the above checks have been carried out,
should circuit diagnosis begin.
See Electrical
Trouble Shooting Manual.
INJECTOR TESTS
NOTE: Before removing any of the
injectors, remove and examine the spark
plugs, check for consistent colouration of
plugs. A leaking injector will result in the
appropriate spark plug being ’sooted up’.
The following test may only be carried out using
suitable injector test equipment.
Leak Test
Leak test with the injectors closed but pressurise to
2.54 Kgf/cm
2
. No injector should leak more than 2
drops of fuel per minute.
Fuel Delivery Test
Fuel delivery test with the injector open and
pressurised as above, fuel delivery from each injector
should be 160-175cc per minute using white spirit, or
180-195cc per minute using petrol at 20˚C æ 2˚C.
19
FUEL SYSTEM
2
FAULT DIAGNOSIS
BASE IDLE SPEED SETTING
NOTE: Base idle speed is set at factory. It
should not require further adjustment
unless plenum chamber is changed. The
adjustment screw is sealed with a plug to prevent
unauthorised alteration. Check ignition timing
before attempting following procedure, since this
will affect idle speed.
Equipment required
Two blanking hoses. these are manufactured using
a new air by-pass valve hose - Part No.ETC7874. Cut
two equal pieces 90mm long from hose and seal one
end of each, using 13mm diameter bar. Use a suitable
clamp to ensure an air tight seal.
Checking procedure
1. Drive vehicle at least two miles until engine and
transmission are hot. Switch off engine.
2. Check all electrical loads are OFF, including air
conditioning.
3. Remove air by-pass valve hose.
4. Fit blanking hoses to both plenum chamber and
air by-pass valve. Ensure hoses are securely
fitted to prevent air leaks. Note throttle cable and
cruise control actuator have been omitted from
illustration.
5. Start engine and check idle speed is within
limits.
See ENGINE TUNING DATA,
Information, Basic Idle Speed
Adjusting base idle speed
6. Drill tamper proof plug and insert a self tapping
screw to enable plug to be extracted.
7. Start engine, adjust idle screw clockwise to
decrease or counter-clockwise to increase idle
speed.
8. Stop engine, remove blanking hoses. Reconnect
hose to plenum.
9. Fit new tamper proof plug.
MFI
3
FAULT DIAGNOSIS
FUEL PRESSURE CHECK
In order to check the fuel pressure it is necessary to
first depressurise the fuel system as follows:
WARNING: Under normal operating
conditions the multiport fuel injection
system is pressurised by a high pressure
fuel pump, operating at up to 2.3 to 2.5 bar. When
engine is stationary pressure is maintained within
system. To prevent pressurised fuel escaping and
to avoid personal injury it is necessary to
depressurise multiport fuel injection system
before any service operations are carried out.
If vehicle has not been run there will be a small
amount of residual pressure in fuel line. The
depressurising procedure must still be carried out
before disconnecting any component within the
fuel system.
The spilling of fuel is unavoidable during this
operation. Ensure that all necessary precautions
are taken to prevent fire and explosion.
A
Pressure gauge 18G1500
B
Fuel tank and pump
C
Fuel filter
D
Fuel injectors x 8
E
Regulator
1. Remove fuel pump relay module.
See Repair,
Multiport Fuel Injection Relay Modules
2. Start and run engine.
3. When sufficient fuel has been used to cause fuel
line pressure to drop, injectors will become
inoperative, resulting in engine stall. Switch off
ignition.
4. Disconnect battery negative lead. .
NOTE: Fuel at low pressure will remain in
system. To remove low pressure fuel,
place absorbent cloth around fuel pipe at
the filter during disconnection.
5. Connect the pressure gauge on the outlet from
the filter, located on the chassis under the right
rear wheel arch.
6. Reconnect the battery and turn the ignition to
position II while observing the pressure gauge.
Results
Expected reading 2,39-2,672 kgf/cm
2
Pressure drop-max 0.7 kgf/cm
2
in one minute.
If pressure is low check that filter is not blocked
and pump is operating satisfactorily. Then
recheck pressure. If pressure is still low renew
regulator.
See Repair, Fuel Pressure
Regulator
MFI
1
REPAIR
AIR CLEANER ASSEMBLY
Service repair no - 19.10.01
Remove
1. Release 2 clips securing air cleaner to air flow
sensor.
2. Release clip and disconnect hose from air
cleaner.
3. Release 2 rubber mountings securing bottom of
air cleaner to body.
4. Slide air cleaner backwards and release from
mounting bracket.
5. Remove air cleaner assembly.
Do not carry out
further dismantling if component is removed
for access only.
6. Release 4 clips securing top of air cleaner and
remove.
7. Withdraw air cleaner element and discard.
Refit
8. Fit new air cleaner element and secure in
position.
9. Reverse removal procedure.
AIR CLEANER ELEMENT
Service repair no - 19.10.08
Remove
1. Release four clips retaining air cleaner cover.
2. Release two clips to air flow meter.
3. Remove air cleaner cover, retain air flow meter
’O’ring.
4. Remove element.
Refit
5. Fit new element.
6. Fit O ring.
7. Position air cleaner cover, secure two clips to air
flow meter.
8. Secure four air cleaner cover clips.
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