fuel pressure LAND ROVER DISCOVERY 1995 User Guide

12ENGINE
4
FAULT DIAGNOSIS 3.Are fuel supply, tank, pump, ventilation and
emission control systems in correct working
order or the fuel contaminated?
NO -
See FUEL SYSTEM, Repair, Fuel
Filter See FUEL SYSTEM, Repair,
Fuel Tank See FUEL SYSTEM, Repair,
Fuel Pump and Sender Unit
YES - Suspect valves held open by hydraulic
tappets due to high oil pressure.
See
Engine Oil Pressure Test
4.Is oil pressure high?
YES - Remove oil filter and cooler adaptor and
check pressure relief valve strainer gauze
for blockage and that the relief valve is
not stuck closed.
See Description and
operation, Description
NO - Carry out cylinder compression tests to
determine condition of head gaskets and
valves.
See Cylinder Compression -
Test
5.Are cylinder compressions satisfactory?
NO -
See Repair, Cylinder Heads - Renew
YES - Check brake vacuum connections.See
BRAKES, Description and operation,
Brake Servo Unit
Check heater/ventilation unit vacuum connections.
See HEATING AND VENTILATION, Description and
operation, Heating and Ventilation Unit
If problem is not diagnosed: Continue.
6.Are the brakes binding?
YES - Investigate cause of binding.
NO - Continue.
7.Automatic Transmission only. Is the Torque
Converter and Transmission operating correctly?
Carry out Road test, Static tests and Stall tests
to determine condition of Automatic
transmission.
If problem is not diagnosed: repeat tests starting at 1.Engine backfires into exhaust system
1.Are there any leaking joints/connections or holes
in the exhaust system?
YES -
See MANIFOLD AND EXHAUST
SYSTEM, Repair, Exhaust System
Complete
NO - Continue.
2.Is distributor fitted correctly, HT leads in correct
firing order and routed correctly?
NO -
See ELECTRICAL, Repair, Distributor
- V8i
YES - Continue.
3.Is air fuel ratio correct?
NO - Check multiport fuel injection.
See
Electrical Trouble Shooting Manual.
Check brake vacuum connections.See
BRAKES, Description and operation, Brake
Servo Unit
Check heater/ventilation unit vacuum
connections.
See HEATING AND
VENTILATION, Description and operation,
Heating and Ventilation Unit
Check the crank case and fuel tank ventilation
system.
See EMISSION CONTROL,
Description and operation, Emission Control
YES - Continue.
4.Are cylinder compressions satisfactory?
NO - Carry out compression test to check for
leaking gaskets valves etc.
See
Cylinder Compression - Test
See Repair, Cylinder Heads - Renew
If problem is not diagnosed: repeat tests starting
at 1.

12ENGINE
12
REPAIR
12.Ensure service tools LRT-12-010 and
LRT-12-091 are scrupulously clean. Coat seal
guide and oil seal journal with clean engine oil.
CAUTION: Do not handle oilseal lip, check
it is not damaged. Ensure outside diameter
remains clean and dry.
13.Position oil seal guide LRT-12-010 on crankshaft
flange.
NOTE: Lubricant coating must cover seal
guide outer surface completely to ensure
that oil seal lip is not turned back during
assembly. Position oil seal, lipped side towards
engine, on seal guide. Seal outside diameter
MUST be clean and dry.
14.Fit oil seal using tool LRT-12-091. Remove seal
guide.
15.Tighten rear main bearing cap to
90 Nm.
16.Fit sump.
17.Fit flywheel or flexible drive plate and ring gear.ENGINE
Service repair no - 12.41.01
Remove
1.Park vehicle on level ground and apply park
brake.
2.De-pressurise fuel system.
See FUEL
SYSTEM, Repair, Depressurising Fuel
System
3.Remove bonnet [hood].See CHASSIS AND
BODY, Repair, Bonnet [Hood]
4.Remove battery.See ELECTRICAL, Repair,
Battery
5.Remove radiator/oil coolers.See COOLING
SYSTEM, Repair, Radiator/Oil Coolers
6.Place an absorbent cloth around fuel feed hose
at fuel rail and release compression nut.
Remove feed hose from rail, seal end of pipes
with masking tape to prevent ingress of dirt.
7.Release fuel return hose clamp and remove
hose from pressure regulator, seal both
openings with masking tape to prevent ingress of
dirt.
8.Remove vacuum hose from rear of regulator.
9.Manual vehicles: Disconnect throttle cable from
bracket. Automatic vehicles: Detach throttle
bracket from plenum chamber and lay assembly
to one side.
See FUEL SYSTEM, Repair,
Plenum Chamber DO NOT DISTURB KICK
DOWN CABLE SETTING.
10.Remove ram housing.See FUEL SYSTEM,
Repair, Ram Housing
11.Remove air flow sensor.See FUEL SYSTEM,
Repair, Air Flow Sensor
12.Remove air cleaner assembly.See FUEL
SYSTEM, Repair, Air Cleaner Assembly
13.Remove Generator.See ELECTRICAL,
Description and operation, Generator
14.Release air conditioning compressor from its
mounting and lay to one side. DO NOT
discharge air conditioning system.
See AIR
CONDITIONING, Repair, Compressor

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.

4.0 V8
7
REPAIR 171.Route drive belt around pulleys.
172.Pivot tensioner downwards.
173.Align belt to tensioner and release tensioner.
174.Connect battery positive lead and tighten.
175.Secure terminal cover.
176.Align gearbox breather pipe, clip to engine lifting
eye and fit bolt. Tighten to
9 Nm.
177.Align and secure engine harness brackets to
inlet manifold and fit nuts. Tighten to
9 Nm.
178.Connect injector multiplugs.
179.Connect air intake temperature sensor multiplug.
180.Connect fuel temperature sensor multiplug.
181.Connect coolant temperature multiplug.
182.Connect temperature gauge connector.
183.Connect oil pressure switch Lucar.
184.Connect camshaft sensor multiplug and secure
to bracket.
185.Fit ignition coil bracket.
See FUEL SYSTEM
SFI, Repair, Ignition Coils
186.Position heater hose/pipe assembly.
187.Connect hose to inlet manifold.
188.Align pipe to bracket and fit bolt. Tighten to
9
Nm.
189.Tighten hose clip.
190.Connect heater return hose and tighten clip.
191.Remove plugs from fuel feed and return hose
connections.
192.Clean feed unions.
193.Connect return hose and tighten clip.
194.Connect feed hose union and tighten.
195.Remove cloth.
196.Connect purge hose.
197.Connect leads to generator, tighten terminal nuts
and fit cover.
198.Connect sensing Lucar.
199.Connect servo vacuum hose.
200.Position expansion tank and secure with fixings.
201.Connect hose and tighten clip.
202.Lower ramp.
203.Fit mass air flow sensor.
See FUEL SYSTEM
SFI, Repair, Mass Air Flow Sensor (MAF
Sensor)
204.Fit plenum chamber.See FUEL SYSTEM SFI,
Repair, Plenum Chamber
205.Fit radiator.See COOLING SYSTEM, Repair,
Radiator
206.Fit bonnet.See CHASSIS AND BODY, Repair,
Bonnet [Hood]
207.Reconnect battery negative lead.
208.Bleed power steering system.
See STEERING,
Repair, Power Steering System - Bleed
209.Drain engine oil and refill.See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
Recommended Lubricants and Fluids - USA
Vehicles
210.Start engine. Check for fuel, coolant and oil
leaks.FRONT COVER GASKET
Service repair no - 12.65.04 - Front Cover Gasket
Remove
1.Disconnect battery negative lead.
2.Drain cooling system.
See COOLING SYSTEM
V8, Adjustment, Coolant
3.Remove radiatorSee COOLING SYSTEM,
Repair, Radiator
4.Remove water pump pulley.See COOLING
SYSTEM, Repair, Viscous Coupling, Fan
Blades, Pulley and Fan Cowl
5.Slacken bottom hose clip. Remove hose from
water pump.
6.Raise vehicle on ramp.
7.Disconnect oil cooler hoses from front cover and
position aside. Plug hoses and connections.
8.Disconnect Lucar from oil pressure switch.

12ENGINE
6
REPAIR ENGINE
Service repair no - 12.41.01
Remove
1.Site vehicle onto ramp [hoist].
2.Remove the drive belt.
See SECTION 10,
Maintenance, Under Bonnet [Hood]
Maintenance
3.Remove radiator.See COOLING SYSTEM,
Repair, Radiator - Mpi
4.Remove bonnet [hood].See CHASSIS AND
BODY, Repair, Bonnet [Hood]
5.Drain engine oil.
6.Position absorbent cloth around fuel pipe to fuel
rail union.
Unscrew union to relieve pressure.
CAUTION: Plug the connections
7.Release clip and disconnect hose from coolant
pump.
8.Release clip and disconnect hose from heater
rail.

Mpi
9
REPAIR 29.Disconnect oil pressure switch multiplug.
30.Disconnect air conditioning compressor
multiplug.
31.Remove 3 bolts securing engine harness to
manifold and fuel pipe.
32.Disconnect knock sensor multiplug.
33.Remove 2 nuts securing harness to starter motor
solenoid, remove harness.
34.Disconnect crankshaft sensor multiplug.
35.Disconnect fuel injection harness multiplug.
36.Disconnect inlet manifold air temperature sensor
multiplug.
37.Release clip and disconnect fuel hose from
pressure regulator.
CAUTION: Plug the connections.

Mpi
13
REPAIR 19.Connect crankshaft sensor, knock sensor, air
conditioning compressor, fuel injector harness,
inlet manifold air temperature and fuel
temperature sensor multiplugs.
20.Connect fuel hose to pressure regulator and
secure with clip.
21.Fit and tighten fuel pipe to fuel rail union.
22.Connect multiplugs to throttle housing.
23.Connect vacuum hose to manifold.
24.Connect oil pressure switch multiplug.
25.Connect brake servo hose to manifold, secure
with clip.
26.Connect throttle cable to cam.
27.Position engine harness and connect breather
hose to inlet manifold, secure with clip.
28.Connect coolant temperature sensor multiplugs,
secure harness with cable tie.
29.Connect oxygen sensor multiplug, secure
harness with cable tie.
30.Connect alternator harness.
31.Connect heater hose to heater rail and secure
with clip.
32.Connect hose to coolant pump and secure with
clip.
33.Connect inlet hose to power steering pump and
secure with clip.
34.Fit and tighten outlet pipe union to power
steering pump.
35.Connect bypass and top hose, secure with clip.
36.Connect air cleaner to throttle housing hose and
secure with clip.
37.Remove engine lifting bracket.
38.Position spark plug cover and secure with
screws.
39.Fill engine with oil.
40.Fit bonnet [hood].
See CHASSIS AND BODY,
Repair, Bonnet [Hood]
41.Fit radiator.See COOLING SYSTEM, Repair,
Radiator - Mpi
42.Adjust throttle cable.See FUEL SYSTEM,
Adjustment, Throttle Cable Adjustment
ENGINE SUMP GASKET
Service repair no - 12.60.43
Remove
1.Drain engine oil.
2.Refit drain plug, use new sealing washer if
necessary, tighten to the correct torque.
3.Remove 18 bolts securing sump.
NOTE: 25mm long bolt is fitted at rear L.H.
corner of sump.
4.Release sump from cylinder block.
5.Discard gasket.

12ENGINE
14
REPAIR Refit
1.Clean sump, remove all traces of gasket from
mating faces of sump and cylinder block.
Visually check sump for damage.
2.Apply beads of RTV sealant to front main
bearing cap.
3.Position new gasket to sump, ensuring that
location pips on gasket are located in sump.
Check gasket lays flat on sump flange.
4.Fit sump. Fit bolts, ensuring that longest bolt is
inserted at position 7.
5.Working around the sump in the sequence
illustrated, tighten the bolts to the stage 1 torque
figure. Then, in the same sequence, tighten the
bolts to the stage 2 torque figure.
NOTE: For torque values.See
Specifications, torque, Torque Values
6.Fill engine with oil.CYLINDER HEAD GASKET
Service repair no - 12.29.01
Remove
1.Disconnect battery negative lead.
2.Position absorbent cloth around fuel pipe to fuel
rail union. Unscrew union to relieve pressure.
CAUTION: Plug the connections.
WARNING: Do not carry out the next
instruction until the coolant is cool to
avoid personal injury from scalding.
3.Release clip and disconnect radiator bottom
hose, allowing coolant to drain into a suitable
container.

12ENGINE
16
REPAIR 14.Release clip and disconnect brake servo hose
from manifold.
15.Disconnect fuel temperature sensor multiplug.
16.Remove 3 bolts securing engine harness to
manifold.
17.Disconnect fuel injection harness multiplug.
18.Disconnect inlet manifold air temperature sensor
multiplug.
19.Release clip and disconnect fuel hose from
pressure regulator.
CAUTION: Plug the connections
20.Release clips and disconnect 3 hoses from
manifold.
21.Remove bolt securing dipstick tube to coolant
rail.

12ENGINE
18
REPAIR Refit
1.Fit location dowels to cylinder head.
2.Fit cylinder head gasket to cylinder block.
3.Using assistance fit cylinder head to cylinder
block.
4.Lubricate cylinder head bolts.
5.Fit and tighten cylinder head bolts to the correct
torque and in the correct sequence.
NOTE: For torque values.See
Specifications, torque, Torque values
6.Fit timing belt.
7.Fit camshaft covers.
8.Fit spark plug leads to spark plugs and secure to
clips.
9.Fit spark plug cover and secure with screws.
10.Fit new gasket and secure downpipe to exhaust
manifold with nuts.
11.Fit bolt securing dipstick tube to coolant rail.
12.Connect 3 vacuum hoses to inlet manifold.
13.Connect fuel to pressure regulator, secure with
clip.
14.Connect fuel injection harness, inlet manifold air
temperature sensor and fuel temperature sensor
multiplugs.
15.Secure engine harness to manifold with bolts.
16.Connect brake servo hose to manifold, secure
with clip.
17.Connect air cleaner hose to throttle housing,
secure with clip.
18.Connect stepper motor and throttle
potentiometer multiplugs.
19.Fit and adjust throttle cable.
20.Connect oxygen sensor multiplug, secure with
cable tie.
21.Connect the bypass and top hose, secure with
clips.
22.Connect coolant temperature sensor multiplugs,
secure with cable tie.
23.Connect hose to heater rail and secure with clip.
24.Connect radiator bottom hose and secure with
clip.
25.Tighten fuel pipe to fuel rail union.
26.Reconnect battery negative lead.