spark plugs NISSAN PULSAR 1987 Workshop Manual

General Information 13

A simple bush removing tool using a bolt, nut, suitable spacer and large and small washers.
Bushes in blind holes can also be removed using
hydraulic force. With the hole packed with grease,
insert a neat fitting drift and tap the drift into the hole.

The pressure of the grease on the rear of the bush
should force it from the hole.

ROTATING THE CRANKSHAFT
There are many occasions when it is necessary to
rotate the crankshaft to a certain position. These
include timing and valve adjustment and checking
valve timing.

To make the engine easier to rotate, remove the
spark plugs. This will re lieve compression pressure.

The simplest method is to use a socket or ring
spanner on the crankshaft pulley nut and turn the
engine in the normal direction of rotation.

On vehicles with manual transmission, the engine
can be turned by selecting top gear and rolling the
vehicle forward. A variation of this method is to raise
one of the driving wheels and, with top gear selected,
rotate the driving wheel in a forward direction to turn
the engine.

Alternatively, the engine can be brought to the
desired position by briefly actuating the starter motor.

25
ENGINE TUNE-UP
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 fo\
r
precautionary notes.

1. TUNE-UP SPECIFICATIONS
Firing orde r................................................... 1 -3-4-2
Spark plugs:
Type .............................................NGK BPR 6ES
Gap ........................................................... 1.1 mm
Tightening torque...................................... 20 Nm
Ignition timing with diagnostic link
connector jumped........................... 10 deg BTDC
Idle speed (ECU controlled):
Manual transaxle 1.8 liter ............ 850 ± 50 rpm
Manual transaxle 1.6 liter............800 ± 50 rpm
Automatic transaxle
(Park or Neutral).......................... 825 ± 50 rpm
Drive belt deflection:
Alternator ........................................... 14-16 mm
Power steering pump ......................... 14-16 mm
Air conditioner compressor .................. 9-11 mm
NOTE: When performing an engine tune-
up, a/ways compare the above Specifications
with the emission control information label
inside the engine compartment.

2. TUNE-UP OPERATIONS
Special Equipment Required:
To Test Compression — Compression gauge
TO SERVICE AIR CLEANER
The air cleaner is equipped with a paper element.
The element should be regu larly inspected but should
not be cleaned in service.

The element should be renewed every 40 000 km.
This distance is only a guide for normal operating
conditions and should be reduced accordingly if the
vehicle is operating under ex tremely dusty conditions.

NOTE: Paper air cleaner elements should
not be washed in petrol or any other type of
cleaning solvent. If the element has been
washed in solvent or has become oil soaked,
it should be discarded and a new element
installed.

1.8 Liter Engine
(1) Release the clamp securing the air intake
hose to the throttle body and disconnect the throttle
cable from the support bracket. (2) Release the clips reta ining the upper air
cleaner housing to the lowe r air cleaner housing and
raise the upper housing while disconnecting the air
intake hose from the throttle body. Remove the air
cleaner element.

The air cleaner element should be renewed at 40 000
km intervals. 1.8 liter engine.
(3) Clean the inside of the air cleaner housing
using a damp rag to remove all traces of dust and
check the upper housing and air inlet hose for cracks
and air leaks. Renew if necessary. (4) Install a new air cleaner element to the lower
housing ensuring that the element is correctly seated
around the edges. (5) Install the upper housing and lock the clips,
securing it to the lower housing. Connect the air
intake hose to the throttle body and the throttle cable
to the support bracket. Tighten the hose clamp
securely. (6) Start the engine and check the air cleaner
assembly for air leaks.

Engine Tune-up 27

move the alternator or power steering pump as
required until the drive belt concerned has the
specified deflection.

On models with air conditioning, loosen the nut
in the centre of the idler pulley and turn the adjusting
bolt until the drive belt has the specified deflection.

(3) Tighten the alternator or power steering
pump bolts securely and check the belt tension.

On models with air conditioning, tighten the idler
pulley nut securely.

TO SERVICE SPARK PLUGS
The spark plugs should be renewed at intervals of
40 000 km.

Before removing the spark plugs ensure that the
area around each plug is cl ean to prevent foreign
matter entering the cylinder when the plugs are
removed.

Spark plugs removed from an engine in good
mechanical condition should have a light powdery
deposit ranging from light brown to grayish tan in
color. After considerable service the electrodes will
show signs of wear or no rmal burning. Spark plugs
showing a thick black oily deposit indicate an engine
in poor mechanical condition or possibly, that a plug
with too low a heat range has been installed.

Spark plugs showing a white or yellowish deposit
indicate sustained high speed driving or possibly that
plugs with too high a heat range have been installed,
particularly when these deposits are accompanied by
blistering of the porcelain and burning of the elec-
trodes.

If the spark plugs are to be cleaned, use a
sandblasting machine and blow clean with com-
pressed air. Ensure that all traces of abrasive grit are
removed from the spark plug threads and from the
well in the plug body. Carefully open the electrode gap
a little, by bending the side electrode, and lightly file
the electrodes flat with a points file.


Black damp deposits can be caused by excessive oil
consumption or incorrect plug type. Spark plugs in this
condition are usually not firing.
Cutaway view of spark plug showing a crack in the
insulator nose which can be caused by exerting pres-
sure against the centre electrode when adjusting the
gap. The other crack shown on the insulator is caused
by tilting the plug spanner.

When plug electrodes are eroded to this degree the
spark can be considered worn out and should be
renewed using a plug of the recommended heat range
.
CRACK

Engine Tune-up
Spark plug with burnt electrodes and white blistered
appearance, possibly due to incorrect plug type, loose
plug or motor running too hot.
NOTE: Never attempt to alter the electrode
gap by bending the centre electrode as
damage to the porcelain insulator will
result.

Before installing any spark plugs measure the gap
between the electrodes, pref erably with clean wire
gauges. If wire gauges are una vailable, use clean feeler
gauges. Move the side electrode towards or away from
the centre electrode to obtain the correct gap-

Screw the plugs into the cylinder head ringer tight,
then use a torque wrench to tighten the plugs lo the
specified torque.



Checking the spark plug electrode gap with a wire
gauge.
NOTE: If a torque wrench is unavailable,
extreme care must be taken when tightening
the spark plugs as over tightening may lead
to stripping of the thread from the cylinder
head. If the plugs are tightened with the
fingers and then taken up an additional 1/4
of a turn with a spark plug wrench, they will
be tight enough.

TO TEST COMPRESSION
(1) With the engine at operating temperature.
disconnect the high tension leads from the spark
plugs.
(2) Ensure that the area around each spark plug
is clean to prevent foreign matter entering the cylin-
ders and remove the spark plugs. (3) Remove the fusible link that is positioned
third from the front of th e fusible link connecting
block, located at the rear of the battery. Disconnect
the coil high tension lead from the coil.
NOTE: Failure to remove the fusible link
can result in an explosion.

(4) Install a compression gauge to number one
spark hole according to the gauge manufacturers
instructions. (5) Have an assistant fully open the throttle and
operate the starter switch to rotate the engine. Ob-
serve the compression gauge and stop the engine when
the gauge has reached the highest reading, usually
after 3 or 4 compression strokes.
(6) Record the reading a nd check the compres-
sion of the remaining cylinders in the same manner.
(7) Compare all the readings taken. Variation
between the highest and lowest reading cylinders
should not exceed 100 kPa. (8) If a low reading is recorded on one or more
cylinders the trouble may be isolated as follows :

Lightly file the plug electrodes flat with a points file

Roadside Trouble Shooting
ing the wiring from any component, ensure
that the ignition switch is off and the
negative battery terminal is disconnected to
prevent damage to the solid state circuitry.

(4) Open the electrode gap of a serviceable spark
plug to 6 mm. Securely earth the plug using a jumper
lead or by tying the plug to an earthed engine
component.
(5) Disconnect the high tension lead from a
spark plug and connect it to the test spark plug.
(6) Have an assistant operate the starter motor.
(7) Check that a spark, if any, jumps the gap on
the test spark plug. If the spark is satisfactory, proceed to operation

(8).
If there is no spark, proceed as follows:
(a) Check the high tension leads to ensure that
they are dry and that the insulation is not cracked or
perished. Check the ends of the leads for burning. Using an ohmmeter, measure the resistance in

each high tension lead. The resistance should be no
more than 15 000 ohms per lead.
(b) Check the distributor cap to ensure that it is
dry and clean. Examine both the inside and outside of
the cap for cracks or tracki ng, particularly between the
high tension lead segments.

Check that the carbon brush in the centre of the
distributor cap interior fa ce is clean and dry and
ensure that the brush moves freely in and out of its
locating hole.

(c) Check the rotor arm for cracks, deposits and
burning on the metal arm. (d) Ensure that the high tension leads have dry.
clean and secure connections on the distributor cap. (8) If the above checks r esult in a good spark at
the spark plug high tension leads but the engine is still
not operating satisfac torily, remove all the spark plugs
and check the condition and electrode gap as de-
scribed in the Engine Tune-up section under the
appropriate heading.

3. TO CHECK FUEL SYSTEM
Due to the complex nature of the EFI system, it is
recommended that should the following checks prove
satisfactory but the engine fail to start, reference be
made to the Fuel and Engine Management section of
this manual or a Nissan workshop be consulted.

(1) Check that the fuel tank contains a reason-
able amount of fuel. (2) Have an assistant switch the ignition on and
off while squeezing the fuel supply hose with the
fingers. If the fuel pump is operating it should be
possible to feel the fuel pr essure increase for approx-
imately two seconds.
NOTE: When conducting the above test it
should be possible to hear the fuel pump and
ignition relays clicking when the ignition is
switched on and off

If the fuel pump relay fails, power will be
supplied to the fuel pump via the oil pressure


Check the distributor cap for cracks or tracking between the terminals. Squeeze the fuel supply hose while the ignition is
switched On. An increase in pressure should be felt.

Check the spark plug high tension leads for cracks and
burnt or corroded terminals.

Roadside Trouble Shooting 35


View showing the location of the fuel pump fuse and the EGI and fuel pump relays.
switch. When starting the engine, the fuel
pump will not operate until the oil pressure
is sufficient to extinguish the oil pressure
warning lamp. Therefore it will be necessary
to operate the starter motor for a longer
period than usual to start the engine.

(3) If the fuel pump cannot be felt operating,
check the fuel pump fuse located in the fuse panel
adjacent to the steering column.

If the fuel pump fuse is serviceable, refer to the
Fuel and Engine Management section for detailed
tests on the fuel pump.

(4) Check that all fuel hose connections are
secure.
(5) Remove the spark plugs and check for petrol
saturation of the electrodes which indicates flooding.
Thoroughly clean and dry the spark plugs before
replacement. Fully depress the throttle pedal and turn the
ignition switch to the start position. If the engine does
not start, proceed as follows.

Check that the MAP sensor hose is not blocked or split
and ensure that all electrical connections are clean and
secure.
If flooding persists, refer to the Fuel and Engine
Management section.

(6) Check that all EFI electrical wiring connec-
tors are clean and secure.
(7) Check that the MAP sensor vacuum hose is
securely connected at each end and is not split or
blocked.
4. TO CHECK MECHANICAL SYSTEM
The following check procedure assumes that the
starter motor will rotate the engine. If not, on manual
transaxle models, depress the clutch pedal to disen-
gage the engine from the tr ansaxle in case the fault lies
within the transaxle.

If the starter motor will not rotate the engine, it
will be necessary to remove the starter motor and
attempt to turn the engine over manually. This will
establish whether the fault lies with the starter motor,
which could be jammed or defective, or with the
engine, which could be seized or have broken internal
components such as connecting rods, pistons and
crankshafts etc.

If the starter motor is not at fault and the engine
will not rotate manually, refer to the Engine Mechan-
ical Trouble Shooting heading in the Engine section.

It should be noted that the only way that cylinder
compression can be accurately tested is with a com-
pression gauge. The method described in the following
procedure is only intended to give a rough indication
when checking for causes of engine breakdown,

(I) When the engine is cool, check for loss of
coolant from the cooling system.

If coolant loss is evident, check carefully for any
indication of external leakage. Remove the engine oil
dipstick and check for wate r contamination (emulsi-
fication) of the oil. When oil mixes with water it will
Ensure that all fuel connections are securely tightened.

36 Roadside Trouble Shooting


Check the engine oil for level and dilution on the dipstick.
turn creamy. The oil level will also have increased. If
the oil is emulsified, proceed to operation (5).

(2) Remove the fusible link that is positioned
third from the front of th e fusible link connection
block, located at the rear of the battery. Disconnect
the coil high tension lead from the coil. (3) Remove all of the spark plugs except one.
(4) Have an assistant operate the ignition switch
to rotate the engine and listen to the sound made by
the engine as it is being turned over. Move the spark
plug to a different cylinder and repeat the lest. By performing the same test on all cylinders, a
rough comparison can be made to determine if there
is any loss of compression in any cylinder. This will be
apparent by the different sound made by the engine as
it is being turned over.

Normally, if the compression is satisfactory the
cylinder with the spark plug installed will create a
resistance to the rotating engine.

However, if the compression is low in a particular
cylinder, the engine will tu rn over easily and smoothly
when that spark plug is in place.

(5) If the above checks show a loss of coolant
which is present in the engine oil or on the spark plug,
one or more of the following faults may be the cause:

Blown cylinder head gasket.
Cracked cylinder or cylinder head.
If the compression check showed any weak or
inconsistent compressions, in addition to the above
faults any of the following could also be the cause:

Broken piston{s)
Burnt or broken valve(s).
Provided the previous checks do not indicate an

View showing the location of the fusible links.
internal leakage of coolant, proceed with the follow-
ing:

(6) Remove the distributor cap and, with the aid
of an assistant operating th e starter motor, check that
the rotor arm rotates as the engine turns over. (7) Remove the camshaft hous ing top cover and.
again with an assistant operating the ignition switch,
check that all the valves open and close as the engine
turns over.
If the rotor arm or valves do not operate with
engine rotation, one of the following faults may be the
cause:

Rotor arm does not turn but valves operate:
Distributor drive shaft broken.

Rotor arm and valves do not operate: Broken
camshaft drive belt. Sheare d crankshaft timing gear
drive key. Sheared camshaft liming gear drive dowel.

Provided that all the previous checks have been
performed correctly and the operator is satisfied that
none of the components are at fault, all that remains
is for the ignition and valve timing to be checked. It
should be noted, however, that if loss of valve timing
proves to be the fault, th e cause of this occurrence
must be sought and rectified.

(8) In order to check the valve timing it will be
necessary to remove the distributor cap and the
camshaft housing top cover and turn the engine
clockwise via the crankshaft pulley until No. 1 piston
is at TDC on the compression stroke. In this position
the valves of No. 1 cylinder should be closed, the
valves of No. 4 should be rocking and the distributor
rotor should be pointing to the No. 1 high tension lead
segment in the distributor cap.

Fuel and Engine Management 83
the fuel pump will not operate until the oil
pressure is sufficient to extinguish the oil
pressure warning lamp. Therefore it will be
necessary to operate the starter motor for a
longer period than usual to start the engine.

(3) Faulty EFI component wiring connections:
Check that all component wiring connections are
clean and secure.
(4) Manifold absolute pressure (MAP) sensor
vacuum hose blocked or disconnected: Clear or recon-
nect the vacuum hose. (5) Fault in the ignition system: Check the
primary and secondary ignition circuits.
(6) Engine flooded: Fully depress the throttle
pedal until the engine starts. Check the coolant
temperature sensor. Check th e injector(s) for leakage.
ENGINE STARTS THEN STALLS

(1) Water in the fuel: Dr ain the fuel from the
system and renew the fuel filter.
(2) Air leakage at the inlet manifold: Check all
joints and hoses for air leaks. (3) Faulty EFI wiring connections: Check that
all component wiring connections are clean and
secure.
(4) Ignition timing incorrectly set: Check and
adjust the timing. (5) MAP sensor faulty or supply hose discon-
nected or blocked: Check the vacuum supply hose.
Check the operation of the MAP sensor.
ENGINE MISFIRES

(1) Faulty, dirty or incorrectly adjusted spark
plugs: Renew or clean and adjust the spark plugs.
(2) Condensation in the distributor cap: Dry and
examine the cap for cracks. (3) Faulty high tension leads: Check and renew
the high tension leads.

Testing the fuel system pressure using a pressure
gauge.
(4) Faulty ignition coil: Check and renew the
ignition coil.
(5) Fuel blockage: Check for blockage in the fuel
filter, lines and injector(s). (6) Low fuel pressure: Check the fuel pump and
fuel pressure regulator. (7) Water in the fuel: Dr ain the fuel from the
system and renew the fuel filter. (8) Loose fuel supply wiring connectors: Check
all connectors for tightness. (9) Faulty fuel injector: Check the connections
and test the condition of the fuel injectors.
ENGINE LACKS POWER

(1) Ignition timing incorrectly set: Check and
adjust the timing.
(2) Water in the fuel: Dr ain the fuel from the
system and renew the fuel filter.
(3) Incorrectly adjusted throttle cable: Adjust the
throttle cable.



Check the distributor cap for cracks or tracking be- tween the terminals. The air filter element should be renewed at 40 000 km
intervals. 1.8 liter engine.

Fuel and Engine Management 85


View of the 1.6 liter engine showing the engine management components. Air cleaner removed for clarity.
series of tests on various components in the system
and records the results, If a fault is discovered, the
ECM warning lamp on the instrument cluster will
illuminate while the engine is running. When the self
diagnosis mode is activated, the ECM warning lamp
will flash codes indicating the area in which the fault
has occurred.

This function is very useful in locating system
faults, particularly intermittent problems. However,
the self diagnosis mode does not provide comprehen-
sive testing of the EFI system, and therefore should
always be used in conjunction with the other test
procedures described later in this section in order to
accurately locate system faults.

The high energy electronic ignition system con-
sists of a distributor and an ignition coil.

The distributor has two functions. The first is to
produce and distribute secondary high tension voltage
to the spark plugs.

The second function is to provide the control unit
with information on engine speed and crankshaft
position.

The ignition timing is constantly adjusted by the
control unit to suit varying engine and vehicle oper-
ating conditions.

In the fuel injection system, a metered amount of
fuel is sprayed into the air stream. The air/fuel

mixture then enters the combustion chamber via the
inlet valves.

On 1.6 liter engines, the fuel is injected by a single
injector, located above the throttle valve within the
throttle body assembly. The injector fires twice per
engine revolution under most operating conditions.

On 1.8 liter engines, four injectors are used. The
fuel is distributed to the injectors via the fuel rail. All
injectors fire simultaneous ly once per engine revolu-
tion under most operating conditions.

Under conditions of high load the control unit
may signal the injector(s) to fire more often. However,
if the engine speed exceeds 6 700 rpm the control unit
will cease firing the injectors until the engine speed is
below 6 200 rpm.

Fuel is supplied under pressu re by an electric fuel
pump mounted in the fuel tank and the pressure is
regulated by a pressure regulator.

On 1.6 liter engines, the regulator consists of a
spring tensioned diaphragm which is mounted to the
side of the throttle body assembly. The fuel pressure is
regulated by the tension of the spring against the
diaphragm, opening and closing the fuel return port.

On 1.8 liter engines, the pressure regulator is
mounted adjacent to the fuel rail and consists of a
diaphragm with fuel pressu re acting on one side and
spring tension and manifold vacuum acting on the

Fuel and Engine Management 105

DISTRIBUTOR
To Remove and Install
(1) Disconnect the negative battery terminal.
(2) Disconnect the distribu tor wiring connec-
tors.
(3) Disconnect the high tension leads from the
spark plugs. (4) Remove the distributor cap retaining screws
and remove the cap and high tension leads from the
vehicle. (5) Turn the engine in the normal direction of
rotation until the mark on the crankshaft pulley aligns
with the timing pointer and the rotor is pointing
towards the No. 1 spark pl ug lead terminal on the
distributor cap. (6) Mark the distributor body to camshaft hous-
ing relationship to aid in setting the ignition timing on
installation.
(7) Remove the distributor retaining nuts and
withdraw the distributor from the camshaft housing.
Installation is a reversal of the removal procedure
with attention to the following points:

(1) Ensure that the engine has not been rotated
while the distributor has been removed. If the engine
has been rotated, align the timing marks and ensure
that No. 1 piston is on the compression stroke.

(2) Check and renew the distributor base O ring
if the sealing quality is suspect. (3) Install the distributor to the camshaft
hous-
ing, aligning the coupling with the slot in the camshaft
and ensuring that the rotor does not move in relation
to the distributor body. Align the marks made on
removal. (4) Install and securely tighten the distributor
retaining nuts. (5) Install the distributor cap and tighten
the
retaining screws.
(6) Connect the distributor wiring connector.
(7) Connect the negative battery terminal and
check the ignition timing as previously described in
this section.
To Dismantle and Assemble
With the distributor removed from the engine and
the distributor cap removed, dismantle the distributor
as follows:

(1) Disconnect the pickup coil wiring connector
from the control module. (2) Measure the resistance between the terminals
on the pickup coil wiring connector and the distribu-
tor body. The r esistance should be infinity.
(3) Measure the resistance between the terminals


View of the distributor removed from the engine show-
ing the pickup coil connector. 0 RING RETAINING SPRING
Dismantled view of the distributor.