1999 LAND ROVER DEFENDER air filter

12ENGINE
20
OVERHAUL GASKET - ENGINE SUMP
Service repair no - 12.60.38.01
Remove
1.Remove 2 bolts securing centrifuge oil drain pipe
to sump, remove and discard gasket.
2.Using sequence shown and noting their fitted
positions, remove 20 bolts securing sump to
cylinder block.
3.Remove sump, remove and discard gasket.
CAUTION: Do not lever between sump and
cylinder block.Refit
1.Clean sump and mating faces, ensure bolt holes
in cylinder block are clean and dry.
2.Using suitable solvent, remove all traces of
sealant from joint faces of timing chain cover and
crankshaft rear oil seal housing.
3.Clean centrifugal filter oil drain pipe and mating
faces.
4.Apply a bead of sealant, Part No. STC 3254 to
joint faces of timing chain cover and crankshaft
rear oil seal housing.
CAUTION: Assembly and bolt tightening
must be completed within 20 minutes of
applying sealant.
5.Position new sump gasket.
CAUTION: Gasket must be fitted dry.
6.Position sump, fit and lightly tighten bolts
ensuring they are in their original fitted positions.
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17 - EMISSION CONTROL
CONTENTS
Page
DESCRIPTION AND OPERATION
EGR SYSTEM COMPONENTS - TYPE 1 2............................................................
EGR SYSTEM COMPONENTS - TYPE 2 4............................................................
EMISSION CONTROL SYSTEMS 6.......................................................................
CRANKCASE EMISSION CONTROL 7..................................................................
EXHAUST GAS RECIRCULATION 8.....................................................................
EGR MODULATOR 9..............................................................................................
INLET THROTTLE (ILT) MODULATOR 10.............................................................
EGR VALVE 11.......................................................................................................
INLET THROTTLE (ILT) VALVE 12........................................................................
IN-LINE AIR FILTER - PRE EU´ u MODELS 13........................................................
EGR SYSTEMS 14.................................................................................................
REPAIR
VALVE - EGR - NON EU3 MODELS 1...................................................................
VALVE - EGR - EU3 MODELS 2............................................................................
INLET THROTTLE (ILT) MODULATOR 3...............................................................
SOLENOID - VALVE - EGR 3.................................................................................
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EMISSION CONTROL
3
DESCRIPTION AND OPERATION 1.EGR Solenoid
2.Vacuum hose (light brown)
3.T-piece
4.Vacuum hose to brake servo
5.Non-return valve
6.Brake servo
7.Inlet manifold
8.Exhaust manifold
9.EGR pipe
10.Vacuum pump/alternator assembly
11.Air intake hose from intercooler
12.EGR valve assembly
13.Vacuum hose to vacuum pump
14.Vacuum hose to EGR valve suction port (blue)
15.To atmosphere
16.In-line filter
17.Vent hose - EGR solenoid to in-line filter (green)
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EMISSION CONTROL
5
DESCRIPTION AND OPERATION
CAUTION: Inset A shows the Pre-EU3 condition for the EGR pipe. Inset B shows the Pre-EU3
condition filter and venting.
1.ILT valve modulator
2.ILT modulator vacuum hose (brown)
3.EGR valve modulator
4.EGR modulator vacuum hose (brown)
5.Vent hose - EGR modulator to in-line filter (green)
6.Vacuum hose to ILT valve suction port (blue)
7.Vacuum hose to EGR valve suction port (blue)
8.’T’-piece (4-way)
9.Vacuum hose to brake servo
10.Non-return valve
11.Brake servo
12.Inlet manifold
13.Exhaust manifold
14.ILT valve
15.EGR cooler - EU-3 models
16.Vacuum pump/alternator assembly
17.Air intake hose from intercooler
18.EGR valve (incorporating ILT valve) assembly
19.Vacuum hose to vacuum pump
20.Vent hose - ILT valve modulator to in-line filter (green)
21.3-way connector
22.Vent hose to air cleaner
23.ILT modulator harness connector (green)
24.EGR modulator harness connector (black)
25.To atmosphere - Pre-EU3 models
26.In-line filter - Pre-EU3 models
27.EGR pipe - Pre-EU3 models
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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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EMISSION CONTROL
13
DESCRIPTION AND OPERATION IN-LINE AIR FILTER - PRE EU´ u MODELS
1.To modulator vent port
2.Filter element3.To atmosphere
The in-line air filter is placed in the ventilation line from the EGR modulator. The modulator needs to be able to
vent to atmosphere in order to release the vacuum supplied to the EGR valve. The filter prevents contamination
entering the modulator via the vent port which could cause failure. The filter should be periodically changed in
accordance with the recommended service intervals. The filter is attached to the RH inner front wing, and is held
in position by a clamping bracket. The filter must be mounted vertically.
NOTE: EU3 models are not fitted with an in-line air filter. The ventilation line connects directly to
the air cleaner housing, where it vents to atmosphere.
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ENGINE MANAGEMENT SYSTEM
7
DESCRIPTION AND OPERATION SENSOR - MASS AIR FLOW (MAF)
The MAF sensor is located in the intake system between the air filter housing and the turbocharger. The ECM
uses the information generated by the MAF sensor to control exhaust gas recirculation (EGR).
The MAF sensor works on the hot film principal. The MAF sensor has 2 sensing elements contained within a film.
One element is controlled at ambient temperature e.g. 25°C (77°F) while the other is heated to 200°C (360°F)
above this temperature e.g. 225°C (437°F). As air passes through the MAF sensor the hot film will be cooled.
The current required to keep the constant 200°C (360°F) difference provides a precise although non-linear signal
of the air drawn into the engine. The MAF sensor sends a voltage of between 0 and 5 volts to the ECM,
proportional to the mass of the incoming air. This calculation allows the ECM to set the EGR ratio for varying
operating conditions.
Inputs / Outputs
The MAF sensor receives battery voltage (C0149-3) via the ECM on a brown/orange wire. Signal output on a
slate/light green wire from the MAF sensor (C0149-2) to the ECM (C0158-11) is a variable voltage proportional to
the air drawn into the engine. The MAF sensor is provided an earth (C0149-1) via the ECM (C0158-20) on a
pink/black wire.
The MAF sensor can fail or supply an incorrect signal if one or more of the following occurs:
Sensor open circuit.
Short circuit to vehicle supply.
Short circuit to vehicle earth.
Contaminated sensor element.
Damaged sensor element.
Damaged wiring harness.
MAF sensor supplies incorrect signal (due to air leak or air inlet restriction).
In the event of a MAF sensor signal failure any of the following symptoms my be observed:
During driving, engine speed may dip before recovering.
Difficult starting.
Engine stalls after starting.
Delayed throttle response.
EGR inoperative.
Reduced engine performance.
MAF signal out of parameters.
In the event of a MAF sensor failure, the ECM will use a fixed default value from its memory.
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