1999 LAND ROVER DEFENDER ECU

12ENGINE
36
OVERHAUL 9.Check that the cut-out in piston skirt is
positioned above the oil squirt jet.
10.Repeat for other pistons in turn ensuring that
pistons and connecting rods are fitted in cylinder
bores from which they were removed.
11.Fit connecting rod bearings.See this Section.
CAUTION: If new pistons, connecting rods
or crankshaft have been fitted, it will be
necessary to select correct thickness of
cylinder head gasket.See this Section.CRANKSHAFT
Service repair no - 12.21.33.01
Remove
1.Remove timing chain and sprockets.See this
Section.
2.Remove crankshaft rear oil seal.See this
Section.
3.Remove connecting rod bearings.See this
Section.
4.Check that cylinder reference number is on each
main bearing cap. Make suitable alignment
marks between each main bearing cap and
cylinder block.
5.Starting at No. 3 main bearing cap and working
outwards, progressively loosen, then remove 2
bolts securing each cap. Discard main bearing
cap bolts.
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ENGINE
37
OVERHAUL
6.Fit 2 slave bolts into each main bearing cap in
turn and ease bearing caps from cylinder block.
7.Remove and discard bearing shells from each
cap.
NOTE: These bearing shells are plain.
8.Using assistance, remove crankshaft.
9.Remove and discard main bearing shells and 2
thrust washers from cylinder block.
NOTE: These bearing shells are grooved.
10.Remove Torx screw securing each oil squirt jet
to cylinder block, remove squirt jets.Cylinder block - Inspection
1.Clean main bearing shell and thrust washer
locations in cylinder block, ensure bolt holes are
clean and dry.
2.Clean main bearing caps.
3.Clean crankshaft bearing journals, check oilways
are clear.
4.Ensure drillings in oil squirt jets are clear.
5.Check core plugs in cylinder block for corrosion
or signs of leakage, seal replacement plugs with
Loctite 243.
Crankshaft - Inspection
1.Check crankshaft main and big-end bearing
journals for scoring, wear and ovality, make 3
checks at 120°intervals in centre of journals.
Crankshaft bearing journal diameters:
Main bearings =
62.000 mm±0.013 mm (2.441 in±0.001 in)
Big-end bearings =
54.000±0.01 mm (2.125±0.0004in)
CAUTION: Crankshafts may not be
reground, only one size of main and
big-end bearing shell is available and if
journals are found to be scored, oval or worn,
crankshaft must be replaced. Main and big-end
bearing shells and thrust washers must be
replaced whenever they are removed.
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12ENGINE
38
OVERHAUL Crankshaft spigot bush
1.Check crankshaft spigot bush for wear, replace if
necessary using the following procedures:
2.Secure crankshaft in a suitably padded vice.
3.Tap a thread in spigot bush to accommodate a
suitable impulse extractor.
4.Fit impulse extractor to spigot bush.
5.Remove spigot bush.
6.Clean spigot bush recess in crankshaft.
7.Fit new spigot bush to crankshaft using a
suitable mandrel.
Crankshaft - Refit
1.Fit oil squirt jets, fit Torx screws and tighten to8
Nm (6 lbf.ft).
2.Lubricate new, grooved, main bearing shells with
engine oil and fit to cylinder block.
3.Lubricate new thrust washers with engine oil and
fit, grooved side facing outwards, to recess in
each side of cylinder block No. 3 main bearing.
4.Lubricate crankshaft journals with engine oil and
using assistance, position crankshaft in cylinder
block.
5.Lubricate new, plain, main bearing shells with
engine oil and fit to main bearing caps.
6.Fit main bearing caps in their original fitted
positions ensuring that reference marks are
aligned.
7.Fit and lightly tighten new main bearing cap
bolts.
CAUTION: Do not lubricate bolt threads.
8.Starting with No. 3 main bearing cap and
working outwards, tighten main bearing cap bolts
to:
Stage 1 -33 Nm (24 lbf.ft)
Stage 2 -Further 90
°
CAUTION: Do not carry out stages 1 and 2
in one operation.
9.Check that crankshaft rotates smoothly.
10.Assemble a magnetic base DTI to front of
cylinder block with stylus of gauge on end of
crankshaft.
11.Using suitably padded levers, move crankshaft
rearwards and zero DTI.
12.Move crankshaft forwards and note crankshaft
end-float reading on gauge.
Crankshaft end-float =0.02 to 0.25 mm (0.001
to 0.011 in)
CAUTION: Oversize thrust washers are not
available, if end-float exceeds figure given,
crankshaft must be replaced.
13.Remove DTI.
14.Fit connecting rod bearings.See this Section.
15.Fit timing chain and sprockets.See this
Section.
16.Fit crankshaft rear oil seal.See this Section.
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EMISSION CONTROL
9
DESCRIPTION AND OPERATION EGR MODULATOR
1.Port to vacuum source (white band)
2.Port to EGR valve (blue band)3.Port to atmosphere via in-line filter (green band)
4.Harness connector
The EGR modulator is located on a plate fixed to the inner RH front wing. The modulator is attached to the plate
by two studs, each with two nuts which secure the assembly to a rubber mounting, which helps reduce noise. The
modulator must be mounted vertically with the two vacuum ports uppermost.
Modulator operation is controlled by a signal from the ECM which determines the required amount of EGR needed
in response to inputs relating to air flow, engine operation, and ambient conditions. The modulator has a two pin
connector at its base to connect it to the ECM via the engine harness.
The modulator features three ports:
The top port is identified by a white band and connects to a T-piece in the vacuum line via a small bore light
brown plastic hose. The two other ports on the T-piece connect to the vacuum line hoses of black vinyl tubing
between the vacuum pump and the brake servo assembly attached to the bulkhead. The vacuum pump end of
the tubing terminates in a rubber elbow, which gives a vacuum tight seal on the suction port of the vacuum
pump. The brake servo end of the tubing terminates with a non-return valve in a plastic housing which plugs
into the front face of the brake servo housing.
The middle port is identified by a blue band, and connects to the suction port on the EGR valve through a small
bore blue plastic hose.
The lower port is identified by a green band and connects to atmosphere through an in-line filter via a small
bore green plastic hose.
The blue and brown vacuum hoses are protected by corrugated plastic sheaths. The ends of the hoses are fitted
with rubber boots to ensure vacuum tight seals at the component ports.
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17EMISSION CONTROL
10
DESCRIPTION AND OPERATION INLET THROTTLE (ILT) MODULATOR
1.Port to vacuum source (white band)
2.Port to ILT valve (blue band)
3.Port to atmosphere via in-line filter (green band)
4.Harness connector (green)
The ILT modulator is located on a plate fixed to the inner wing on the RH side of the engine below the EGR
modulator. The modulator is attached to the plate by two through-studs, each with two nuts which secure the
modulator assembly to a rubber mounting which helps to reduce noise. The modulator must be mounted in the
vertical orientation with the two vacuum ports uppermost.
The modulator operation is controlled by a signal from the ECM which determines the required ratio of exhaust
gas to fresh inlet air needed in response to inputs relating to air flow and engine operating and ambient conditions.
The modulator has a green two-pin connector at its base to connect it to the ECM through the engine harness.
The ILT valve modulator features three ports:
The top port is identified by a white band and connects to a’T’-piece in the vacuum line via a small-bore brown
plastic hose where it is connected in parallel with the vacuum source line to the EGR valve modulator. The two
other ports on the’T’-piece connect vacuum line hoses of black vinyl tubing between the vacuum pump
attached to the alternator and the brake-servo assembly attached to the bulkhead.
The middle port is identified by a blue band and connects to the suction port on the ILT valve through a
small-bore blue plastic hose.
The lower port is identified by a green band and connects to atmosphere through an in-line filter via a green
plastic hose and a three-way connector positioned in-line between the modulators and the filter. The ILT
modulator hose is connected opposite to the two parallel ports at the three-way connector which connect the
vent lines to the EGR valve modulator and the in-line filter. The other port of the in-line filter vents directly to
atmosphere.
The blue and brown vacuum hoses are protected by corrugated plastic sheaths. The ends of the hoses are fitted
with rubber boots to ensure vacuum tight seals at the component ports.
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17EMISSION CONTROL
14
DESCRIPTION AND OPERATION EGR SYSTEMS
There are two types of exhaust gas recirculation system used with the Td5 engine dependent on legislation and
market requirements, these are type 1 and type 2.
Type 1 EGR system is fitted to all Td5’s built up to the introduction of 2002 MY, except for Japanese specification
vehicles.
Type 2 EGR system is fitted to all Japanese specification vehicles and was introduced into European markets for
2002 MY to meet EU3 emission requirements. An additional feature introduced at 2002 MY is the EGR cooler,
which is bolted to the front of the cylinder head.
EGR System - Type 1
This EGR system features a modulator which is electrically controlled to modulate a vacuum source to the EGR
valve. The controlled vacuum opens the valve by the amount required to ensure the optimal proportion of exhaust
gas is allowed through to the inlet manifold to be combined with the fresh air intake. Control feedback is achieved
by monitoring the mass of fresh air flowing through the MAF sensor.
EGR modulator operation is controlled by a signal from the ECM, which determines the required amount of EGR
needed in response to inputs relating to air flow and engine operating and ambient conditions. The ECM is
low-side driven, sinking current returned from the vacuum modulator for switching operating condition.
The exhaust gases are routed from the exhaust manifold through a shaped metal pipe which connects to the
underside of the EGR valve. The pipe is held securely in position to the front of the cylinder head using a clamp
bracket. The EGR pipe is attached to a mating port at the front end of the exhaust manifold using 2 Allen screws,
and at the EGR valve assembly by a metal band clamp. The 2 Allen screws should be replaced every time the
EGR pipe is removed.
CAUTION: Extreme caution should be exercised when removing and refitting the EGR pipe to
avoid damage.
When a vacuum is applied to the EGR suction port, it causes a spindle with sealing disc (EGR valve) to be raised,
thus opening the port at the EGR pipe to allow the recirculated exhaust gas to pass through into the inlet manifold.
The valve is spring loaded so that when the vacuum is removed from the suction port the valve returns to its rest
position to tightly close the exhaust gas port.
By controlling the quantity of recirculated exhaust gas available in the inlet manifold, the optimum mix for the
prevailing engine operating conditions can be maintained. This ensures the intake gas to the combustion
chambers will have burning rate properties which will reduce NO
Xemissions to an acceptable level. Normally, full
recirculation is only applicable when NO
Xemissions are most prevalent.
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EMISSION CONTROL
15
DESCRIPTION AND OPERATION EGR System - Type 2
This system features twin modulators mounted one above the other on a metal plate located on the inner wing at
the RH side of the engine. The modulators are electrically controlled by the engine management system and are
used to modulate a vacuum source to the EGR valve and a supplementary Inlet Throttle (ILT) valve; the two
valves are controlled to operate in tandem. The ILT valve vacuum pot is mounted adjacent to the EGR valve
housing and has a linkage which connects to a butterfly valve mounted in front of the EGR valve at the air intake
manifold.
The modulator operations are electrically controlled by signals from the engine management system which
determines the required volume of exhaust gas needed in response to inputs relating to air flow, engine operating
conditions and ambient parameters such as temperature and altitude. The engine management ECM switches on
the circuit by completing the path to ground, operating the vacuum modulators.
Pre EU3 models:The exhaust gases are routed from the exhaust manifold through a shaped metal pipe which
connects to the underside of the EGR valve. The pipe is held securely in position to the front of the engine cylinder
head using a metal clamp bracket. The EGR pipe is attached to a mating port at the front end of the exhaust
manifold using two Allen screws and at the EGR valve assembly by a metal band clamp. The two Allen screws
fixing the EGR pipe to the exhaust manifold should be replaced every time the EGR pipe is removed.
CAUTION: Extreme care should be exercised when removing and refitting the EGR pipe to avoid
damage.
EU3 models:The exhaust gases are routed from the exhaust manifold through the EGR cooler to the underside
of the EGR valve. The EGR cooler is bolted to the front of the engine cylinder head. An EGR pipe connects the
EGR cooler to the exhaust manifold and is secured by two Allen screws. The two Allen screws fixing the EGR pipe
to the exhaust manifold should be replaced every time the EGR pipe is removed. A second pipe connects the
EGR cooler to the EGR valve; this pipe is secured to the EGR valve by a clip, and to the cooler by two Allen
screws.
CAUTION: Extreme care should be exercised when removing and refitting the EGR pipe to avoid
damage. When refitting the EGR cooler, always tighten the pipe connections BEFORE tightening
the bolts securing the cooler to the cylinder head.
When a vacuum is applied to the EGR suction port, it causes a spindle with sealing disc (EGR valve) to be raised,
opening the port at the EGR pipe to allow the recirculated exhaust gas to pass through into the inlet manifold. The
valve is spring loaded so that when the vacuum is removed from the suction port, the valve returns to its rest
position to tightly close the exhaust gas port.
A vacuum is simultaneously applied to the inlet throttle (ILT) valve suction port which causes the butterfly valve in
the inlet manifold to close by means of a spindle and lever mechanism. Closing the butterfly valve limits the supply
of fresh intercooled air entering the inlet manifold and causes a depression within the inlet manifold to create a
greater suction at the open port to the EGR delivery pipe. In this condition a greater mass of recirculated exhaust
gas is drawn into the inlet manifold for use in the combustion process. When the vacuum is released from the ILT
valve suction port a spring returns the butterfly valve to its fully open position.
By controlling the quantities of recirculated exhaust gas and fresh intake air available in the inlet manifold, the
optimum mix for the prevailing engine operating conditions can be maintained which ensures the intake gas to the
combustion chambers will have burning rate properties which will reduce the NO
2emissions to an acceptable
level. Normally, full recirculation is only applicable when the NO
2emissions are most prevalent.
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EMISSION CONTROL
1
REPAIR VALVE - EGR - NON EU3 MODELS
Service repair no - 17.45.01
Remove
1.Disconnect battery negative lead.
2.Remove 3 bolts and remove engine acoustic
cover.
3.Remove cooling fan.See COOLING SYSTEM,
Repair.
4.Remove battery cover.
5.Disconnect battery negative lead.
6.Disconnect vacuum hose from EGR valve
7.Loosen clip screw and release air intake from
EGR valve.
8.Remove 4 bolts, release EGR valve from inlet
manifold and discard gasket.
9.Remove 2 bolts and release EGR valve clip from
cylinder head.
10.Remove and discard 2 Allen screws securing
EGR valve pipe to exhaust manifold.
11.Remove EGR valve assembly.
12.Remove clip and remove pipe from EGR valve.Refit
13.Clean EGR valve and mating face on pipe.
14.Position pipe to EGR valve, fit retaining clip and
finger tighten bolt.
15.Clean inlet manifold face.
16.Position EGR valve to inlet manifold using new
gasket and tighten bolts to10 Nm (7lbf.ft).
17.Position air intake hose and tighten clip screw.
18.Position EGR pipe bracket, fit bolts and finger
tighten.
19.Position EGR valve pipe to exhaust manifold and
finger tighten allen screws
20.Tighten EGR valve clip to5 Nm (3 lbf.ft).
21.Tighten EGR pipe bracket bolts to10 Nm (7
lbf.ft).
22.Tighten 2 Allen screws to10 Nm (7 lbf.ft).
23.Connect vacuum hose to EGR valve.
24.Fit cooling fan.See COOLING SYSTEM,
Repair.
25.Fit engine acoustic cover.
26.Reconnect battery negative lead.
27.Fit battery cover.
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