Nissan PULSAR N13 Series / ASTRA LD Series. Manual — part 7

Engine Tune-up

29

Check the cylinder compressions using a compression

gauge.

(a) Inject a small amount of engine oil into the

spark plug hole of the cylinder concerned ensuring
that the oil is evenly distributed within the cylinder by
rotating the engine.

(b) Repeat the compression test on the cylinder

concerned.

A substantial increase of compression pressure

indicates faulty or worn piston rings, pistons or
cylinder.

No increase of compression pressure indicates

burnt, obstructed or sticking valves, or a leaking or
blown cylinder head gasket.

(9) Install the fusible link and connect the high

tension lead to the coil.

TO SERVICE THE DISTRIBUTOR

The electronic ignition system requires virtually

no maintenance except for checking of the distributor
cap. rotor and high tension leads as described below.

Refer to the Fuel and Engine Management section

for Specifications and Trouble Shooting.

NOTE: When working on or near electronic
ignition systems, care should be taken as
dangerous high voltages are present in both
the primary and secondary circuits.

The ignition switch should be turned off

before removing or installing any electrical
connections otherwise damage to the igni-
tion system as well as severe electrical shock
could result.

TO SERVICE HIGH TENSION LEADS

Check the leads for perishing or cracking and

renew as required. Never attempt to repair defective
carbon impregnated core leads.

The lead may be carefully cleaned, using cloth

moistened with kerosene and then wiped completely
dry.

If an ohmmeter is available the electrical resis-

tance of the leads may be checked as follows:

View showing the location of the fusible links.

Check the spark plug high tension leads for cracks and

burnt or corroded terminals.

Check the distributor cap for cracks or tracking

between the terminals

.

30

Engine Tune-up

(1) With the distributor cap and leads removed

as an assembly, test one lead at a time, connecting the
meter probes at the spark plug end of the lead and at
the corresponding terminal inside the cap. Resistance
should be less than 15 000 ohms.

(2) If the resistance is more than 15 000 ohms

remove the lead from the distributor cap and check
(he resistance in the lead only. The lead should be
renewed if the resistance is still more than 15 000
ohms.

(3) High distributor cap resistance may be due

to corrosion deposits on the cap terminals. These
deposits should be removed with a small scraper or
emery cloth.

Check the distributor cap for cracks or tracking

between the high tension terminals on both the inside
and outside of the cap. Renew the cap if cracks or
tracking are evident.

Check the carbon brush in the centre of the

distributor cap for evidence of arcing and renew as
necessary.

Check the condition of the rotor and renew if

arced excessively or cracked.

HOW TO CONNECT ELECTRICAL TEST
EQUIPMENT

NOTE: Some types of tachometers, timing
lights and ignition system analysers are not
compatible with this type of electronic igni-
tion system and may result in incorrect
readings. It is therefore recommended that
the manufacturer of the test equipment be
consulted before using the equipment.

Do not allow the tachometer lead connec-

tor to short to earth as damage to the test
equipment or ignition system may result.

Timing Light

(1) Connect the timing light to the engine fol-

lowing the instrument manufacturers instructions.

NOTE: Do not connect or disconnect the
timing light with the engine running as
voltage surges could damage the alternator.
Do not allow the high tension leads to open
circuit as damage to the ignition system
could result.

(2) Where necessary, connect the power leads of

the timing light to an external power source to prevent
possible transient voltages in the timing light damag-
ing the vehicle alternator.

Tachometer

(1) Ensure that the tachometer is compatible

with the vehicle ignition system.

(2) Disconnect the resistor from the tachometer

View showing the location of the tachometer pickup

wiring connector with the resistor installed

.

pick up wiring connector which is located on the
ignition coil wiring harness, and connect the positive
lead of an accurate tachometer to the brown wire
terminal in the wiring connector.

(3) Connect the negative lead to a good earthing

point.

TO CHECK AND ADJUST IGNITION TIMING

(1 ) Connect an accurate tachometer and timing

light to the engine as previously described.

View showing the location of the diagnostic link

connector. Passengers seat removed for clarity.

Inset shows the diagnostic link connector terminal

identification.

(2) Start the engine and allow it to reach normal

operating temperature.

(3) Connect a jumper lead between terminals A

and B on the diagnostic link connector.

(4) With the engine idling at the specified speed,

check the ignition timing with the timing light.

Correct timing exists when the marks on the

crankshaft pulley are aligned with the pointer on the
inner timing cover.

Engine Tune-up

View of the engine timing marks showing the 10 deg
BTDC crankshaft notch aligned with the pointer on the

front of the engine.

(5) If adjustment is necessary, loosen the distrib-

utor body retaining nuts and turn the distributor body
until the correct setting is obtained.

(6) Tighten the distributor body retaining nuts

and ensure that the timing is still correct.

(7) Remove the jumper lead from the diagnostic

link connector.

(8) Disconnect the timing light from the engine.

TO ADJUST IDLE SPEED AND MIXTURE

The idle speed and mixture are not adjusted as

normal service procedure. However, should the per-
formace of the vehicle indicate that the mixture is
incorrect, refer to the Fuel and Engine Management
section for the procedures to test for faulty compo-
nents in the engine management system.

32

ROADSIDE TROUBLE SHOOTING

CAUTION: To prevent severe electrical shock extreme care must be taken when
working on or near the electronic ignition system as dangerous high tension voltages
are produced in both the primary and secondary circuits. See the text for
precautionary notes.

This section deals with the common causes of

engine failure to start, as inevitably there will come a
time when every driver will experience this problem
and will therefore need to call upon his own resources
to rectify the trouble. Roadside breakdowns other
than engine failure can be identified by reference to
the Trouble Shooting section on the particular com-
ponent affected.

1. TROUBLE SHOOTING

Trouble shooting is only a process of elimination

and provided the procedure is carried out correctly
and systematically an accurate diagnosis of the trouble
can be made in the minimum amount of time.

For an internal combustion engine to run there

are three basic requirements, these are ignition, fuel
and compression. There are other factors of course
but as a rule an engine's failure to start can be
attributed to a fault in one of these three systems.

Reports from field engineers of motoring organi-

sations prove that the biggest percentage of engine
breakdowns are in the order of ignition or electrical
failure first, followed by fuel, with mechanical or
compression failure the least common.

Should the engine fail to start, first check that

there is adequate fuel in the tank and if so. carry out
the following checking procedures in the order de-
scribed.

TO JUMP START A VEHICLE

NOTE: Jump starting a vehicle can be
dangerous if the procedure described below
is not performed correctly. If any doubt
exists, it is recommended that the services of
a competent mechanic be obtained.

The vehicles covered by this manual are

equipped with complex electronic circuitry
which can be damaged by voltage surges.
These voltage surges can be generated when

jump starting, or being jump started by
another vehicle. If available use jumper
leads equipped with a surge protection de-
vice and follow the lead manufacturers in-
structions carefully, particularly regarding
the connection and disconnection of the
leads.

(1) Ensure that the booster battery is 12 volts

and the negative terminal is earthed.

(2) Ensure that the vehicles are not touching and

that the ignition and all accessories on both vehicles
are switched Off.

(3) Ensure that the transmissions on both vehi-

cles are in Park or Neutral and the handbrakes are
firmly applied.

(4) Remove the vent caps from the battery and

check the electrolyte level. Replenish with distilled
water as necessary.

View showing the correct jumper lead connections for

jump starting a vehicle. The leads shown are equipped

with a surge protection device.