1995 LAND ROVER DISCOVERY ECU

MANIFOLD AND EXHAUST SYSTEM
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DESCRIPTION AND OPERATION CATALYTIC CONVERTERS - V8i
Description
Catalytic converters which form part of the engine
emission control system, are designed to 'clean' the
exhaust gases, by closely controlling the fuel air ratio
delivered to the engine and converting the residual
exhaust compounds into products more acceptable to
the environment.
The front section of the exhaust system to each
cylinder bank contain the ceramic elements of the
catalytic converters. The oxygen sensors which
transmit information to the fuel ECU for control of the
mixture, are located in the exhaust down pipes.
The Hydrocarbons (HC), Nitogen oxides (NO
x) and
Carbon monoxide (CO) emitted by the engine react
with the catalytic element and exhaust temperature to
convert the toxic gas, into Nitrogen (N), Carbon
dioxide (CO
2) and water vapour.Should the engine be supplied with a rich mixture
causing high CO in the exhaust gas, the ceramic
element will become coated and the useful life of the
catalyst reduced. If the mixture is too weak, excess
oxygen in the exhaust gas will cause the catalysts to
burn out.
1. Catalysts
2. Lambda oxygen sensors

30MANIFOLD AND EXHAUST SYSTEM
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REPAIR Remove
Catalysts - remove and refit 1 to 5
1.Raise vehicle on a ramp [hoist].
2. Catalyst vehicles only:Disconnect two heated
oxygen sensor wiring connectors.
NOTE: NAS models have four heated
oxygen sensors fitted.
3.Remove two nuts securing rear exhaust
assembly to front exhaust assembly.
4.Remove nuts and release front downpipes from
manifolds. Discard gaskets.
5.Lower front exhaust assembly with catalysts (if
fitted), retain olive.
NOTE: Assistance is required for removing
and refitting rear exhaust assembly.
6.Remove bolts securing three hanger brackets to
chassis. Lower exhaust assembly onto rear axle.
Detach rubbers from hanging brackets.
7.Place extended axle stands underneath chassis,
in front of chassis mounted rear towing brackets.
8.Lower ramp[hoist] until vehicle weight is
supported securely on stands.
9.Lower ramp [hoist] until rear shock absorbers
are ALMOST fully extended.
10.Move rear exhaust to a diagonal position, centre
silencer to right of vehicle.
11.Facing rear of vehicle, twist assembly
anti-clockwise clear of rear axle.
12.Remove rear exhaust assembly from vehicle.
Refit
13.Position rear exhaust assembly over rear axle in
a diagonal position, as for removing.
14.Twist assembly clockwise until it is in mounting
position.
15.Reverse removal procedure. 1. to 9. using new
manifold gaskets and applying exhaust sealer to
system joint.
16.Examine system for leaks, ensuring that system
does not foul underbody components. Rectify if
necessary.EXHAUST MANIFOLD - V8i
Service repair no - Left hand - 30.15.10
Service repair no - Right hand - 30.15.11
Remove
1.Disconnect front exhaust pipe(s) from
manifold(s).
2.Tap back bolt locking tabs and remove eight
bolts, lock tabs and washers.
3.Remove manifold(s) and old gaskets.
Refit
4.Ensure that mating surfaces of cylinder head
and exhaust manifold are clean and smooth.
5.Coat threads of each bolt with anti-seize
compound.
6.Place manifold and new gaskets in position on
cylinder head and fit securing bolts, new
lockplates and plain washers. Plain washers are
fitted between manifold and lockplates.
7.Evenly tighten manifold bolts to
20Nmbend
over lockplate tabs.
8.Reconnect front exhaust pipe, using new
exhaust flange gaskets.

MANIFOLD AND EXHAUST SYSTEM
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REPAIR MANIFOLD AND EXHAUST SYSTEM - Tdi
Remove
1.Raise vehicle on a ramp [hoist].
2.Remove anti-roll[sway] bar bolts to chassis and
allow to swing down clear of axle.
See REAR
SUSPENSION, Repair, Anti-roll [sway] Bar
Assembly Rear
3.Remove exhaust support bracket behind
catalyst.
4.Disconnect exhaust at manifold.
5.Disconnect flange between rear and front
exhaust.
6.Fit axle stands in suitable place on chassis.
7.Allow hoist to lower until front suspension is fully
extended.
8.Manoeuvre front exhaust section fron
underneath vehicle.
9.Remove bolts securing three hanger brackets to
chassis. Lower rear exhaust assembly onto rear
axle. Detach rubbers from hanging brackets.
10.Place extended axle stands underneath chassis
in front of chassis mounted rear towing brackets.11.Lower hoist until vehicle weight is supported
securely on stands.
12.Lower hoist until rear suspension is almost fully
extended.
13.Move rear exhaust to a diagonal position, centre
silencer to right of vehicle.
14.Facing rear of vehicle, twist assembly
anti-clockwise clear of rear axle.
15.Remove rear exhaust assembly from vehicle.
Refit
16.Position rear exhaust assembly over rear axle in
a diagonal position, as for removing.
17.Twist assembly clockwise until it is in mounting
position.
18.Reverse removal procedure instructions 1 to 15
using a new manifold gasket and applying
exhaust sealer to system joints.
19.Examine system for leaks, ensuring that system
does not foul under body components. Rectify if
necessary.

30MANIFOLD AND EXHAUST SYSTEM
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REPAIR EXHAUST MANIFOLD - Tdi
Service repair no - 30.15.10
Remove
1.Disconnect battery negative lead.
2.Remove heat shield from rear of air intake
manifold.
3.Release dip stick tube from cylinder block.
4.Disconnect the intake hose from the manifold.
5.Remove the two bolts and two nuts securing the
intake manifold to the cylinder head and
withdraw the inlet manifold.
6.Remove air filter inlet pipe to turbo unit.
7.Remove intercooler pipe from turbo to
intercooler.
8.Disconnect the EGR pipe from the inlet manifold
hose.
9.Remove the three fixings at the exhaust pipe
flange.
10.Release the turbo charger oil pipes from the
cylinder block.
11.Remove the turbo boost pipes.
12.Remove seven bolts securing the exhaust
manifold, release the heater rail and remove the
manifold gasket, complete with turbo unit.
13.Remove four bolts and disconnect diaphragm
rod from manifold, and remove turbo charger if
necessary.
Refit
14.Reverse removal procedure. 1 to 12. Use a new
manifold and exhaust flange gaskets.
15.Reconnect battery negative lead. Start engine
and check for leaks.

30MANIFOLD AND EXHAUST SYSTEM
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REPAIR 10.Release clip and disconnect breather hose from
manifold.
11.Release 2 bolts securing cam cover brackets to
manifold.
12.Remove 3 bolts securing engine harness to
manifold.
13.Disconnect 3 vacuum hoses from manifold.
14.Release clip and disconnect fuel hose from
pressure regulator.
CAUTION: Plug the connections.
15.Disconnect intake air temperature sensor
multiplug.
16.Disconnect fuel injector harness multiplug.
17.Remove 2 nuts and 7 bolts securing manifold to
cylinder head
18.Remove manifold assembly and collect gaskets.

MANIFOLD AND EXHAUST SYSTEM
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REPAIR Refit
19.Ensure mating faces of inlet manifold and
cylinder head are clean.
20.Fit a new gasket, position inlet manifold to
cylinder head.
21.Fit nuts and bolts, tighten in the order shown to
the correct torque
25Nm
22.Position engine breather hose to manifold and
secure with bolts.
23.Connect fuel injector harness and intake air
temperature sensor multiplug.
24.Connect fuel hose to pressure regulator and
secure with clip.
25.Fit fuel pipe to fuel rail, tighten union to
10Nm
26.Connect vacuum hoses to manifold.
27.Position engine harness and cam cover brackets
to manifold, secure with bolts.
28.Connect breather hose and brake servo hose to
manifold, secure with clips.
29.Connect multiplug to fuel temperature sensor.
30.Connect breather hose to throttle housing and
secure with clip.
31.Connect throttle cable to cam and secure to
abutment bracket.
32.Connect coolant bypass hose to throttle housing.
33.Connect stepper motor and throttle
potentiometer multiplugs.
34.Connect air cleaner hose to throttle housing and
secure with clip.
35.Connect battery negative lead.
36.Adjust throttle cable.EXHAUST MANIFOLD GASKET - Mpi
Service repair no - 30.15.12
Remove
1.Raise vehicle.
2.Loosen 2 nuts securing downpipe to silencer
box.
3.Remove 4 nuts securing downpipe to exhaust
manifold.
4.Release downpipe from exhaust manifold.
5.Discard gasket.

30MANIFOLD AND EXHAUST SYSTEM
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REPAIR 6.Disconnect oxygen sensor multiplug.
7.Release multiplug from bracket on thermostat
housing.
8.Release harness from cable tie.
9.Remove drive belt.
10.Remove 2 front bolts securing generator to
mounting bracket.
11.Remove 2 rear bolts securing generator to
mounting bracket.
12.Move generator from mounting bracket and
place aside.
13.Remove exhaust manifold heat shield.
14.Remove dipstick and bolt securing dipstick tube
to coolant rail.
15.Remove dipstick tube from cylinder block.16.Remove 3 bolts and 2 nuts securing exhaust
manifold to cylinder head.
17.Release coolant rail bracket from manifold studs.
18.Remove exhaust manifold and discard gasket.
Refit
NOTE: For torque values.See
Specifications, torque, Torque Values
19.Clean mating faces of exhaust manifold and
cylinder head.
20.Fit new manifold gasket and align exhaust
manifold to cylinder head.
21.Position coolant rail bracket to manifold studs.
22.Fit manifold nuts and bolts, tighten to the correct
torque in the order shown.
23.Secure oxygen sensor multiplug to bracket.
24.Connect oxygen sensor multiplug.
25.Fit new manifold flange gasket and align exhaust
front pipe to manifold.
26.Fit nuts and tighten diagonally to the correct
torque.
27.Tighten exhaust downpipe to silencer box nuts
to the correct torque.
28.Position generator to mounting bracket.
29.Fit and tighten 4 generator securing bolts.
30.Refit drive belt.

30MANIFOLD AND EXHAUST SYSTEM
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REPAIR 10.Release clip and disconnect breather hose from
manifold.
11.Release 2 bolts securing camshaft cover
brackets to manifold.
12.Disconnect 4 vacuum hoses from manifold.
13.Remove 6 bolts securing manifold chamber to
lower manifold.
14.Remove manifold chamber and collect gaskets.
Refit
NOTE: For torque values.See
Specifications, torque, Torque Values
15.Ensure mating faces of manifold chamber and
lower manifold are clean.
16.Fit a new gasket, position manifold chamber to
lower manifold.
17.Fit bolts, tighten to the correct torque.
18.Connect vacuum hoses to manifold.
19.Position camshaft cover brackets to manifold,
secure with bolts.
20.Connect breather hose and brake servo hose to
manifold, secure with clips.
21.Connect multiplug to fuel temperature sensor.
22.Connect breather hose to throttle housing and
secure with clip.
23.Connect throttle cable to cam and secure to
abutment bracket.
24.Connect coolant bypass hose to throttle housing.
25.Connect stepper motor and throttle
potentiometer multiplugs.
26.Connect air cleaner hose to throttle housing and
secure with clip.
27.Reconnect battery negative lead.
28.Adjust throttle cable.