Defender (1993+). Manual — part 98

ELECTRICAL EQUIPMENT

DISTRIBUTOR - LUCAS 35DLM8

Overhaul

16. Renew pick-up and base plate assembly if

module is known to be faulty, otherwise check
pick-up winding resistance (2k-5k ohm).

DISTRIBUTOR COVER

RE-ASSEMBLY

1.

Unclip and remove the cover.

17. This is mainly a reversal of the dismantling

2.

Renew the cover if known to be faulty.

3.

Clean the cover and

HT

brush with a nap free

cloth.

LUBRICATION

procedure, noting the following points:

ROTOR ARM

Apply clean engine oil:

4. Pull rotor arm from keyed shaft.
5.

Renew rotor arm if known to be faulty.

a. Three drops to felt pad reservoir in rotor shaft.

Apply Chevron SR1 (or equivalent) grease.

INSULATION COVER (Flash shield)

b. Auto advance mechanism.

d. Pre tilt spring and its rubbing area (pick-up

and base plate assy).

VACUUM UNIT

e. Vacuum unit connecting peg (pick-up and

base plate assy) and

8. Remove two screws from vacuum unit

f.

the connecting peg hole in vacuum unit

6. Remove cover, secured by three screws.

c. Pick-up plate centre bearing.

7.

Renew cover if known to be faulty.

securing bracket, disengage vacuum unit

connecting rod.

connecting rod from pick-up base plate
connecting peg, and withdraw vacuum unit

FITTING PICK-UP AND BASE PLATE ASSEMBLY

from distributor body.

18. Pick-up leads must be prevented from fouling

AMPLIFIER MODULE

the rotating reluctor. Both leads should be
located

in

plastic carrier as illustrated. Check

9. Remove two screws and withdraw the module.

during re-assembly.

10. Remove the gasket.
11.

Remove two screws securing the cast
heatsink and remove the heatsink.

WARNING: The amplifier contains Beryllia.

Do

not open or crush.

PICK-UP AND BASE PLATE ASSEMBLY

12. Use circlip pliers to remove the circlip

retaining the reluctor on rotor shaft.

13.

Remove the flat washer and then the ' O ' ring
recessed in the top of the reluctor.

14. Gently withdraw the reluctor from the shaft,

taking care not

to

damage the teeth.

REFlTTlNG RELUCTOR

19. Slide reluctor as far as

it

will go on rotor shaft,

then rotate reluctor until it engages with the
coupling ring beneath the pick-up base plate.
The distributor shaft, coupling ring and reluctor
are 'keyed' and rotate together. Fit the 'O'
ring, flat washer and retaining circlip.

NOTE: Coupling ring fitted beneath reluctor.

15. Remove three support pillars and cable

grommet. Lift out the pick-up and base plate
assembly.

NOTE:

Do

not disturb the two barrel nuts

securing the pick-up module, otherwise the air
gap will need re-adjustment.

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REISSUED: FEB 1993

ELECTRICAL EQUIPMENT

compression stroke.

PICK-UP AIR GAP ADJUSTMENT

2. Turn distributor drive until rotor arm

IS

approximately 30° anti-clockwise from number
one sparking plug lead position on cap.

20. The air gap between the pick-up limb and

reluctor teeth must be set within the specified
limits, using a non-ferrous feeler gauge.

21. If adjustment is necessary, slacken the two

barrel nuts to set the air gap. See Engine

Tuning Data.

3.

Fit distributor to engine.

4. Check that centre line of rotor arm is now

in

line with number one sparking plug lead on
cap. Reposition distributor if necessary.

5. If distributor does not seat correctly in front

drive is not engaged. Engage

sing down distributor while

turning engine.

6. Fit clamp and bolt leaving both loose at this

stage.

7 .

Connect the vacuum pipe to the distributor.

8. Fit low tension lead to coil.
9.

Fit distributor cap.

10.

Reconnect the battery.

11.

Using suitable electronic equipment set the
ignition timing dynamically.

Dynamic ignition timing

Equipment required

Calibrated Tachometer
Stroboscopic lamp

NOTE: When the original pick-up and base plate

assembly has been refitted the air

gap

should be

checked, and adjusted if necessary.

1.

Couple

stroboscopic

timing

lamp

and

tachometer

to

engine

following

the

When renewing the assembly the air gap will

manufacturers instructions.

require adjusting to within the specified

limits.

2.

Disconnect the vacuum pipes from the
distributor.

AMPLIFIER MODULE

3. Start engine, with no load and not exceeding

3,000

rev/min, run engine until normal

22. Before fitting the module, apply MS4 Silicone

operating temperature is reached. (Thermostat

grease

or

equivalent heat - conducting

open). Check that the normal idling speed

compound to the amplifier module backplate,

falls within the tolerance specified in the data

the seating face on distributor body and both

section.

faces of the heatsink casting.

4.

Idle speed for timing purposes must not

exceed 750 rpm, and this speed should be
achieved by removing a breather hose NOT

BY ADJUSTING IDLE SETTING SCREWS

1.

It

is essential that the following procedures

5.

With the distributor clamping bolt slackened

are adhered to. Inaccurate timing can lead to

turn distributor until the timing flash coincides

serious engine damage and additionally create

with the timing pointer and the correct timing

failure to comply with the emission regulations

mark on the rim of the torsional vibration

applying to the country of destination. If the

damper as shown in the engine tuning

engine is being checked in the vehicle and

is

section.

fitted with an air conditioning unit the

6.

Retighten

the

distributor

clamping

bolt

compressor must be isolated.

securely. Recheck timing in the event that

2.

On initial engine build, or if the distributor has

retightening has disturbed the distributor

been disturbed for any reason, the ignition

position.

timing must be set statically to 6° B.T.D.C.

IGNITION TIMING ADJUSTMENT

7.

Refit vacuum pipes.

(This sequence is to give only an approximation in

8.

Disconnect stroboscopic timing lamp and

order that the engine may be started) ON NO
ACCOUNT MUST THE ENGINE BE STARTED

BEFORE THIS OPERATION IS CARRIED OUT

Static ignition timing

tachometer from engine.

1.

Set engine - No. 1 piston to 6° B.T.D.C. on

REISSUED:

FEB

1993

5

ELECTRICAL EQUIPMENT

ELECTRONIC IGNITION - PRELIMINARY CHECKS

EXPECTED READINGS

Inspect battery cables and connections to ensure

they are clean and tight. Check battery state

of

charge if in doubt as to its condition.
Inspect all LT connections to ensure that they are
clean and tight. Check the

HT

leads are correctly

positioned and not shorting to earth against any
engine components. The wiring harness and
individual cables should be firmly fastened to prevent

chafing.

V1.

More than 11.5 volts

V2.

1

volt max below volts at point

1

in

test circuit

V3.

1

volt max below volts at point

1

in test circuit

V4. 0 volt 0.1 volt

PICK-UP AIR GAP

Check air gap with a non-ferrous feeler gauge.

NOTE: The gap is set initially at the factory and
will only require adjusting if tampered with or
when the pick-up module

is

replaced.

TEST 1:

Check HT Sparking

Remove coil/distributor

HT

lead from distributor cover

and hold approximately 6 mm from the engine block.
Switch the ignition 'on' and operate the starter.
If

regular sparking occurs, proceed to Test 6. If

no

sparking proceed to Test

2.

(c) If all readings are correct proceed to Test 3.

(d) Check incorrect reading(s) with chart to

identify area of possible faults, i.e. faults listed
under heading 'Suspect'.

(e) If coil or amplifier is suspected, disconnect LT

lead at coil, repeat V3. If voltage is still
incorrect, fit new coil. If voltage is now correct,

check

LT

lead, if satisfactory

fit

new amplifier.

(f) If engine will not start proceed to Test 3.

KEY

O K Expected Voltage.
H Voltage higher than expected.

L Voltage lower than expected.

TEST 3:

Check Amplifier Switching

Connect the voltmeter between battery positive (-ve)
terminal and

HT

coil negative (- ve) terminal: the

voltmeter should register zero volts.

Switch the ignition

'on'

and crank the engine. The

voltmeter reading should increase just above zero, in
which case proceed with Test

5.

TEST

2:

L.T.

Voltage

Switch the ignition

'ON'

(a) Connect voltmeter to points in the circuit

indicated by the arrow heads and make a
note of the voltage readings.

(b) Compare voltages obtained with the specified

values listed below:

6

REISSUED:

FEB

1993

ELECTRICAL

EQUIPMENT

If

there is no increase in voltage during cranking

proceed to Test 4.

TEST 5:

Coil

HT Sparking

Remove existing coil/distributor HT lead and fit test
HT lead to coil tower. Using suitable insulated pliers,
hold free end about 6 mm from the engine block and

crank the engine. There should be

a

good HT spark.

If weak or no sparking,

fit

new coil, repeat test.

HT sparking good, repeat test with original HT lead.
If sparking is good, carry out Test 6.

If

weak or no sparking, fit new HT lead, if engine will

not start carry out

Test

6

TEST 4:

Pick-Up Coil Resistance.

Disconnect the pick-up leads at the harness

connector. Connect the ohmmeter leads to the two
pick-up leads in the plug.

The ohmmeter should register between 2k and 5k
ohms if pick-up is satisfactory. If the ohmmeter
reading is correct, check all connections between
pick-up and amplifier, if satisfactory, fit new amplifier.

If the engine still does not start carry out Test 5.

Change the pick-up if ohmmeter reading is incorrect.
If

the engine still does not start proceed to Test

5.

TEST

6:

Rotor

Arm

Remove distributor cover. Disconnect coil HT lead

from cover and using insulated pliers, hold about 3

mm above rotor arm electrode and crank the engine.

There should be no HT sparking between rotor and

HT lead.

If

satisfactory carry out Test 7 .

If HT sparking occurs, an earth fault on the rotor arm

is indicated. Fit new rotor arm.

If engine will not start carry out Test 7 .

REISSUED:

FEB 1993

7