spark plugs LAND ROVER DISCOVERY 1995 Workshop Manual

ENGINE TUNING DATA
1
INFORMATION ENGINE 3.9 V8i
Type3.9 Litre V8i .................................................................................
Firing order1-8-4-3-6-5-7-2 .....................................................................
Cylinder Numbers
Left bank 1-3-5-7..........................................................................
Right bank 2-4-6-8........................................................................
No 1 Cylinder locationPulley end of left bank ...................................................
Timing marksOn crankshaft vibration damper ..................................................................
Spark plugs
Make/type(8.13:1 Compression) Champion RN11YCC......................................
Gap 0.84-0.96mm..................................................................................
Make/type(9.35:1 Compression) Champion RN11YCC......................................
Gap 0.84-0.96mm..................................................................................
Coil
Make/type Bosch 0-221-122-392,........................................................................
Compression ratio8.13:1 or 9.35:1 .........................................................
Fuel injection systemLucas 14 CUX Hot-wire air flow sensor system .....................................................
electronically controlled
Valve Timing Inlet Exhaust
Opens 32°BTDC .............................................................................. 70°BBDC
Closes 73°ABDC .............................................................................. 35°ATDC
Duration 285° ........................................................................... 285°
Valve peak 104°ATDC ....................................................................... 114°BTDC
Idle speed - controlled by MFI system
- all loads off in neutral 665 to 735 rev/min.....................................................
- auto gearbox in gear, air con operating 650±28 rev/min .........................
- auto gearbox in gear, air con off 600±28 rev/min ....................................
- manual gearbox 700±28 rev/min .............................................................
- manual gearbox, air con operating 750±28 rev/min ................................
Base idle speed525±25 rev/min
See FUEL SYSTEM, Fault..............................................................
diagnosis, Base idle speed setting.
Ignition Timing - dynamic at 800 rev/min max,
vacuum disconnected
8.13:1 compression, non catalyst 2°BTDC±1° .....................................
9.35:1 compression, non catalyst 4°BTDC±1° .....................................
9.35:1 compression, catalyst 5°BTDC±1° ............................................
Exhaust gas
CO content at idle 0.5 to 1.0% max.............................................................

ENGINE TUNING DATA
3
INFORMATION ENGINE 4.0 V8
Type4.0 Litre V8 .................................................................................
Firing order1-8-4-3-6-5-7-2 .....................................................................
Cylinder Numbers
Left bank 1-3-5-7..........................................................................
Right bank 2-4-6-8........................................................................
No 1 Cylinder locationPulley end of left bank ...................................................
Spark plugs
Make/type Champion RN11YCC........................................................................
Gap 0.90 - 1.00 mm.................................................................................. 0.035 - 0.040 in
Coils
Make Lucas 2D1S2................................................................................
Type Twin coils, bank of 4.................................................................................
High Compression Low Compression
Compression ratio 9.35:1............................................................ 8.2:1
Fuel injection systemSagem - Lucas GEMS8 Hot-wire air flow sensor .....................................................
system electronically controlled
Valve Timing Inlet Exhaust
Opens 28°BTDC .............................................................................. 66°BBDC
Closes 77°ABDC .............................................................................. 39°ATDC
Duration 285° ........................................................................... 285°
Valve peak 108°ATDC ....................................................................... 110°BTDC
Idle speed - controlled by GEMS system
all loads off 700±20 rev/min ..............................................................
Base idle speedNot adjustable ..............................................................
Idle air control valve position, checked viaTestBook
CO at idle
vehicles without heated oxygen sensors 1.5% ñ 0.5%.................
Fuel
9.35:1 catalyst 95 RON minimum unleaded.................................................................
USA vehicles - Premium unleaded (PUG) 95 RON minimum.......................
8.2:1 catalyst 91 RON minimum unleaded.................................................................
Non catalyst 91 RON minimum unleaded or leaded.........................................................

05ENGINE TUNING DATA
6
INFORMATION ENGINE - Mpi - 2.0 LITRE
Type/Capacity 20 T4/1994 cm
3..................................................................
Firing order 1-3-4-2.......................................................................
Compression ration 10 : 1..........................................................
Idle speed:
Controlled by ECM 875±50 rev/min ...........................................................
Exhaust gas Co content:
- Catalyst 0.5% Max. Not adjustable..................................................................
- Non Catalyst 1,0±25% adjustable using Testbook .........................................................
Ignition
Knock sensor ADU 8229...................................................................
Crankshaft sensor ADU 7340............................................................
Ignition Coils
Type NEC 10049.................................................................................
Primary resistance at 20°C 0.4 to 0.61 ohm..............................................
Consumption - engine idling 0.25 to 0.75 amp.............................................
Spark Plugs
Type/Gap GSP 6662 -0,85 mm.........................................................................
Multipoint Fuel Injection
Type Indirect multipoint injection with engine control module.................................................................................
using speed/density method of air flow measurement.
Fuel pressure regulator MKW 10011....................................................
Fuel pump delivery pressure 2.3 - 2.5 bar............................................
Throttle potentiometer voltage
- Throttle closed 0 - 1 Volt......................................................
- Throttle open 4 - 5 Volts.........................................................
MEMS engine control module MKC 10121..........................................
95 RON minimum -UNLEADEDfuel
CAUTION: Do not use LEADED fuel as it will
damage the catalyst. Serious damage to the
engine may occur if a lower octane number fuel
than that recommended is used.

10MAINTENANCE
4
MAINTENANCE UNDER BONNET [HOOD] MAINTENANCE
CHECK COOLING/HEATER SYSTEMS
Check cooling/heater systems for leaks and hoses for
security and condition.
Cooling system hoses should be changed at first
signs of deterioration.
CHECK CONDITION OF ENGINE MOUNTING
RUBBERS
CHECK BRAKE SERVO HOSE FOR SECURITY
AND CONDITION
CHECK FUEL EVAPORATIVE LOSS CONTROL
SYSTEM FOR LEAKS - V8i CATALYST, Mpi
CHECK FUEL FILLER CAP SEAL FOR LEAKS - V8i
- CATALYST, Mpi
CHECK CONDITION OF HEATER PLUG WIRING
FOR FRAYING, CHAFING AND DETERIORATION -
Tdi
CHECK IGNITION WIRING
Check ignition wiring and high tension leads for
fraying, chafing and deterioration.
CLEAN DISTRIBUTOR CAP - V8i
The electronic ignition employs a Lucas 35DLM8
distributor.
Internal operating parts of distributor are pre-set at
factory and do not normally require resetting.
Adjustments should only be made if unit is known to
be faulty or damaged. Distributor maintenance
consists of following items.
1.Clean outer surfaces of distributor cap to remove
dirt, grease etc.
2.Unclip cap, check cap for cracks.
3.Wipe inside cap with lint free cloth.
4.Check rotor arm, cap and flash shield tracking.
DO NOT DISTURB clear plastic insulating
cover (flash shield) which protects magnetic
pick-up module.
LUBRICATE DISTRIBUTOR ROTOR SPINDLE - V8i
Apply a spot of clean engine oil into rotor spindle after
rotor arm has been removed.
CLEAN/ADJUST SPARK PLUGS - V8i CATALYST
RENEW SPARK PLUGS V8i - V8i CATALYST
Clean, adjust and renew
1.Take great care when fitting spark plugs not to
cross-thread plug, otherwise costly damage to
cylinder head will result.

MAINTENANCE
5
MAINTENANCE 2.Clean or replace spark plugs as applicable.
3.It is essential that correct type of spark plugs are
fitted.
4.Incorrect grade of plugs may lead to piston
overheating and engine failure.
Remove
5.Disconnect battery negative lead. Remove H.T.
leads from spark plugs.
6.Remove plugs and washers.
7.When pushing leads onto plugs, ensure that
shrouds are firmly seated.Fitting H.T. leads
8.Ensure replacement H.T. leads are correctly
refitted as illustrated.
Failure to observe this instruction may result in
cross-firing between two closely fitted leads
which are consecutive in firing order.
3.9 V8
4.0 V8

10MAINTENANCE
6
MAINTENANCE
RENEW SPARK PLUGS - Mpi
Spark plugs - Mpi
Remove
1.Release 4 screws and remove spark plug cover.
2.Disconnect 4 plug leads.
3.Release plug leads from securing clips.
4.Remove spark plugs from cylinder head.
Refit
5.Inspect spark plugs.
6.Set plug gaps.
CAUTION: Use correct type and grade of
plug.
7.Apply anti-seize to plug threads. Fit spark plugs.
8.Connect and route spark plug leads as
illustrated.
9.Refit spark plug cover.

V8i
1
FAULT DIAGNOSIS ENGINE OIL PRESSURE TEST
Service tools:
LRT-12-052: Pressure test equipment
WARNING: Use suitable exhaust
extraction equipment, if test is being
carried out in workshop.
WARNING: If vehicle has been running,
engine oil will be hot, care must be taken
when fitting equipment to prevent
personal injury due to scalding.
Test
1.Check lubricant is to correct level.
2.Place vehicle on a ramp [hoist].
3.Disconnect battery negative lead. Remove oil
pressure switch.
4.Fit the test gauge.
5.Reconnect battery negative lead.
6.Start and run engine to normal operating
temperature.
7.At a steady engine speed of 2500 rev/min -
engine oil pressure reading should be - 2.75 bar
(40 lbf/in
2).
8.If the pressure is low - Remove and overhaul oil
pump
CYLINDER COMPRESSION - TEST
Equipment:
Compression pressure gauge
Test
1.Start and run engine until normal engine
operating temperature is achieved (thermostat
open).
2.Remove all spark plugs.
3.Disconnect both coil negative (WB) leads
4.Insert compression gauge, crank engine until
reading stabilises.
5.Expected readings, throttle fully open, battery
fully charged:
8.31:1 = 10.2-10.9 bar, 150-160lbf/in
2
9.35:1 = 11.5-12.2 bar, 170-180lbf/in2

V8i
5
REPAIR CYLINDER HEADS - RENEW
Service repair no - 12.29.15
1.Remove cylinder heads and gaskets.
See
Cylinder Head Gaskets - Renew
2.Remove spark plugs.
3.Using spring compressor LRT-12-034, remove
seals, valves, collets, springs and caps.
CAUTION: Keep components in fitted
order
4.From left hand cylinder head, remove earth lead
studs.
5.Remove three bolts securing power steering
pump mounting bracket to cylinder head.
6.Remove four bolts securing generator mounting
bracket to cylinder head.
7.Right hand cylinder head, remove rear lifting
bracket.
8.Fit lifting bracket to new right hand cylinder
head.
9.Fit mounting brackets and earth lead studs to
new cylinder head. Tighten bolts to
30 Nm.
10.Regrind valves- refer to engine overhaul
publication
11.Lubricate valve stems, fit valves, springs, and
caps. Fit new inlet and exhaust valve stem seals.
12.Using spring compressor LRT-12-034, compress
springs, fit collets. Tap valve to check correct
collet seating.
13.Fit spark plugs.
14.Fit cylinder heads with new gaskets.
See
Cylinder Head Gaskets - Renew
ROCKER COVER - RIGHT HAND - RENEW
Service repair no - 12.29.41
1.Disconnect battery negative lead.
2.Disconnect purge pipe from charcoal canister at
plenum.
3.Remove breather pipe from rocker cover.
4.Remove coolant pipes from inlet manifold.
5.Remove spark plug leads from plugs and
retaining clips.
6.Remove four rocker cover bolts. Moving fuel
pipes aside, remove rocker cover.
7.Discard rocker cover gasket.
8.Remove plug lead retaining clips from rocker
cover, fit to new rocker cover.
9.Clean and dry rocker cover and cylinder head
mating faces, using Bostik cleaner 6001.
NOTE: Gasket fits one way round only. It
must be fitted accurately, first time.
Subsequent movement will destroy
bonding.
10.Apply Bostik 1775 impact adhesive to rocker
cover seal face and gasket, using a brush to
ensure an even film. Allow adhesive to become
touch dry.

12ENGINE
6
REPAIR 11.Place one end of gasket into cover recess with
edge firmly against recess wall, holding
remainder of gasket clear. Work around cover,
pressing gasket into place ensuring edge firmly
contacts recess wall.
12.Allow cover to stand for thirty minutes before
fitting.
13.Fit rocker cover to cylinder head with four
screws, short screws inboard, tighten to
9 Nm.
14.Position fuel pipes.
15.Fit breather pipe to rocker cover, tighten clip.
16.Fit coolant pipes to inlet manifold, tighten bolts.
17.Fit spark plug leads to plugs and retaining clips.
18.Connect purge pipe from charcoal canister at
plenum, tighten clip.
ROCKER COVER - LEFT HAND - RENEW
Service repair no - 12.29.40
1.Remove air flow sensor.
See FUEL SYSTEM,
Repair, Air Flow Sensor
2.Remove plenum chamber.See FUEL SYSTEM,
Repair, Plenum Chamber
3.Remove dipstick.
4.Remove spark plug leads from plugs and
retaining clips.
5.Disconnect HT lead from coil.
6.Remove generator heat shield securing nut from
rocker cover.
7.Remove air flow meter harness clip.
8.Remove bolt securing dipstick tube clip.
9.Remove four rocker cover bolts, remove rocker
cover.
10.Discard gasket
11.Remove plug lead retaining clips from rocker
cover, fit to new rocker cover.
12.Clean and dry rocker cover and cylinder head
mating faces, using Bostik cleaner 6001.
NOTE: Gasket fits one way round only. It
must be fitted accurately, first time.
Subsequent movement will destroy
bonding.
13.Apply Bostik 1775 impact adhesive to rocker
cover seal face and gasket, using a brush to
ensure an even film. Allow adhesive to become
touch dry, approximately fifteen minutes.
14.Place one end of gasket into cover recess with
edge firmly against recess wall, holding
remainder of gasket clear. Work around cover,
pressing gasket into place ensuring edge firmly
contacts recess wall.
15.Allow cover to stand for thirty minutes before
fitting.
16.Fit rocker cover to cylinder head with four
screws, short screws inboard. Tighten to
9 Nm.
17.Position dipstick tube clip. Fit and tighten bolts.
18.Fit and tighten air flow meter harness clip.
19.Fit generator heat shield to rocker cover.
20.Connect HT lead to coil.
21.Connect spark plug leads to plugs and retaining
clips.
22.Fit dipstick.
23.Fit plenum chamber.
24.Fit air flow meter.

4.0 V8
3
REPAIR ENGINE ASSEMBLY
Service repair no - 12.41.01/99
Remove
1.Position vehicle on ramp.
2.Remove bonnet.
See CHASSIS AND BODY,Repair, Bonnet [Hood]
3.Remove radiator.See COOLING SYSTEM,
Repair, Radiator
4.Remove plenum chamber.See FUEL SYSTEM
SFI, Repair, Plenum Chamber
5.Remove mass air flow sensor.See FUEL
SYSTEM SFI, Repair, Mass Air Flow Sensor
(MAF Sensor)
6.Slacken hose clip securing bottom hose to
expansion tank.
7.Disconnect hose.
8.Remove 2 nuts securing expansion tank.
9.Remove nut and bolt securing expansion tank.
10.Remove expansion tank.
11.Disconnect servo vacuum hose from ram
housing.
12.Disconnect battery sensing lead Lucar from
generator.
13.Remove generator terminal cover.
14.Remove 2 terminal nuts and release leads from
terminals.
15.Release purge hose from ram pipe housing.
16.Position cloth to absorb fuel spillage.
17.Slacken clip securing fuel return hose to fuel rail.
18.Disconnect hose.
19.Plug connections.
20.Disconnect fuel feed hose union.
21.Plug connections. Position hoses aside.
22.Slacken clip securing heater return hose to pipe.
23.Disconnect hose.24.Slacken clip securing heater feed adaptor hose
to inlet manifold.
25.Remove bolt securing pipe bracket.
26.Disconnect feed hose from inlet manifold.
27.Disconnect hose/pipe assembly.
28.Disconnect leads from spark plugs and remove
ignition coils.
See FUEL SYSTEM SFI, Repair,
Ignition Coils
29.Disconnect fuel temperature sensor multiplug.
30.Disconnect coolant sensor multiplug.
31.Disconnect temperature gauge sensor lead.
32.Release camshaft sensor multiplug from bracket
and disconnect multiplug.
33.Disconnect oil pressure switch Lucar.
34.Disconnect air intake temperature sensor
multiplug.
35.Disconnect 8 injector multiplugs.
36.Remove 4 nuts securing harness brackets to
inlet manifold.
37.Release harness brackets.
38.Remove bolts securing gearbox breather pipes
to engine lifting bracket.