check engine NISSAN PULSAR 1987 User Guide

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

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 li nk 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 inst alling 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 a ttempt to repair defective
carbon impregnated core leads.

The lead may be carefully cleaned, using cloth
moistened with kerosene a nd 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 in side 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.

32
ROADSIDE TROUBLE SHOOTING
CAUTION: To prevent severe electrical shock extreme care must be taken w\
hen
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.

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 accur ate 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 bigg est 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 av ailable 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.

Roadside Trouble Shooting
(5) Place the vent caps loosely over the cell
apertures.

(6) Connect one end of the red jumper lead to
the positive ( + ) battery terminal of the booster
battery and the other end of the red lead to the
positive (+) battery terminal of the discharged bat-
tery.

NOTE: The battery emits hydrogen gas
which is explosive. Do not expose the battery
to naked /lames or sparks.

Do not lean over the battery when con-
necting the jumper leads.

Do not allow the ends of the jumper leads
to touch one another or any part of the
engine.

(7) Connect one end of the black juniper lead to
the negative (-) battery terminal of the booster
battery and the other end of the black lead to a good
earthing point on the engine of the vehicle with the
discharged battery.

NOTE: Do not connect the jumper lead
directly to the negative (-) battery terminal
of the discharged battery.

(8) Start the engine on the vehicle with the
booster battery and run the engine at a moderate
speed. (9) Start the engine on the vehicle with the
discharged battery.
(10) If possible, leave the engines of both vehi-
cles running for 10 minutes.
(11) Disconnect the jumper leads in the reverse
order of the sequence in which they were connected.
2. TO CHECK IGNITION AND ELECTRICAL SYSTEM

(1) Switch on the ignition and check for warning
lamp illumination on the dashboard. (2) Operate the starter and check that the starter
rotates the engine at a steady speed.
(3) Switch on the headlamps and check for good
light intensity. Should the lamps not illum inate or the starter
motor not turn the engine, carry out the following
steps:

(a) Remove the battery terminals and clean both
terminals and posts. Connect the terminals and where
applicable tighten firmly but not excessively.
(b) Check that the earth lead from the battery to
the engine or body frame is not broken and that the
connections are clean and secure. . (c) Check that the lead from the battery to the
starter motor or starter solenoid is intact and has a
clean and secure connection.


Ensure that the battery posts and terminals are clean.
(d) Where necessary carry out repairs to (b) and
(c).

Repeat the check procedur e. Should the starter
motor still not operate, or the lamps not illuminate,
one or more of the following faults may be the cause:

No starter motor operation or lamps: Battery flat
or defective.

Lamps illuminate but no starter operation: Starter
motor drive jammed in mesh with flywheel ring gear.
Starter motor or solenoid defective. Ignition/starter
switch faulty. On automatic transaxle models, faulty
neutral safety switch.

Lamps dim and starter operation sluggish: Dis-
charged battery or fault in starter motor. Battery flat
due to broken fan belt or de fective alternator. Faulty
battery due to cell breakdown.

NOTE: Electronic ignition systems can pro-
duce dangerously high voltages in both the
primary and secondary circuits. For this
reason, extreme care must be taken when
performing these checks. When disconnect-


Securely earth the body of a test spark plug to check
for sparks at the spark plug leads.

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.

Engine 39
Oil pump cover plate screws............................ 6 Nm
Oil pump mounting bolts.................................. 6 Nm
Oil pump pickup bolts
(coat with Loctite 242)..................................... 8 Nm
Sump bolts (coat with Loctite 242) .................. 5 Nm
Sump drain plug .............................................. 35 Nm
*Use new bolts
Head bolts maximum torque 135 Nm

1. ENGINE MECHANICAL TROUBLE
SHOOTING

ENGINE MISSES AT IDLING SPEED
NOTE: For other causes of engine misfire,
refer to the Fuel and Engine Management
section.

(1) Blown head gasket: Check the cylinder com-
pressions and renew the he ad gasket as necessary.
(2) Burnt valves or seats in the cylinder head:
Check the cylinder compressions and overhaul the
cylinder head as necessary. (3) Broken or worn piston rings: Check the
cylinder compressions and renew the piston rings as
necessary.
(4) Weak or broken valve springs: Remove the
camshaft housing top cover and check the condition
of the valve springs. (5) Air leak at the inlet manifold gasket; Check
for air leaks by applying oil around the manifold
joints. Renew the gasket if an air leak is evident.
NOTE: Use a compre ssion gauge and check
the compression pressure in each cylinder as
described in the Engine Tune-up section. If
a low pressure reading is indicated in one or
more cylinders, remove the cylinder head for
gasket and valve inspection. Should the


gasket and valves prove satisfactory, inspect
the cylinder bores, pistons and rings.

Check for air leaks at the inlet manifold
by applying engine oil around the manifold
joints. If the oil can be seen or heard sucking
into the manifold or excessive smoke begins
to issue from the exhaust system, there is an
air leak at the inlet manifold.

NOISY VALVE OPERATION
(1) Faulty hydraulic tappets: Renew the faulty
tappet assemblies. (2) Weak or broken valve springs: Remove the
camshaft housing top cover and check the condition
of the valve springs. (3) Worn valve guides: Overhaul the cylinder
head as described in this section. (4) Worn rocker gear: Remove (he rocker gear
and check the components for wear.

Camshaft lobe wear is also a cause of noisy valve
operation.
BIG END BEARING NOISE
(1) Inadequate oil supply: Check the oil level in
the sump and the condition of the oil pump and relief
valve. Renew the oil filter.

(2) Excessive bearing clearance: Renew the bear-
ing shells, check and regrind the big end journals if
oval or tapered. (3) Thin oil or oil diluted by petrol or water:
Change to the correct oil grade. Check and rectify the
cause of the oil dilution. Ch eck that the engine is not
operating in overheat conditions.
(4) Low oil pressure: Check the engine oil level.
Check the pressure relief valve and spring and the oil
filter bypass valve. (5) Misaligned big end bearings: Align the con-
necting rods and renew the big end bearing shells.
NOTE: Big end bearing noise is indicated
by a metallic knock wh ich is usually loudest
at approximately 60 km/h with the throttle
Air leaks at the inlet manifold can be located by
applying engine oil around the suspect joints.

40 Engine


Check the engine oil for level and dilution on the dipstick.
dosed. Before dismantling the engine to
inspect the big ends check the engine oil for
correct level and dilution on the dipstick.
Also, remove the oil pressure sender unit
and connect an oil pressure gauge into the
oil gallery to check the oil pressure readings.

MAIN BEARING NOISE (APPARENT)
(1) Loose flywheel: Tighten the flywheel securing
bolls to the specified torque. (2) Low oil pressure: Check the bearing to
journal clearance. Check the condition of the oil
pump and pressure relief valve. Recondition the oil
pump as necessary. (3) Excessive crankshaft end float: Renew the
main bearings. (4) Crankshaft journals out of round and exces-
sive bearing to journal clear ance: Regrind the journals
and renew the bearings (undersize).
(5) Insufficient oil supply: Replenish the oil in
the sump to the correct level.
NOTE: Main bearing noise is indicated by a
heavy but dull knock when the engine is
under load. A loose flywheel is indicated by
a thud or dull click when the ignition is
turned off. It is us ually accompanied by
vibration.

Crankshaft end float noise is indicated by
a sharp rap at idle speed. The crankshaft
can be readily checked for excessive end
float by levering the crankshaft backwards
and forwards.

If the oil pressure is not satisfactory,
remove the main bearing caps and assess
the bearing clearance using the Plastigage
method as described in this section. Ovality
and wear on the main bearing journals can
only be checked with a micrometer after the
crankshaft has been removed.

EXCESSIVE OIL CONSUMPTION
(1) Oil leaks: Check and renew the engine gas-
kets or seals as necessary.
(2) Damaged or worn valve stem oil seals:
Dismantle the cylinder head and renew the damaged
or worn oil seals. (3) Excessive valve stem to valve guide clear-
ance: Ream the valve guides and renew the valves as
necessary. (4) Worn or broken piston rings: Renew the
piston rings on all pistons. (5) Rings too tight or stuck in the grooves:
Renew the rings and clean the ring grooves.
(6) Excessive wear in the cylinders, pistons and
rings: Recondition the cylinders and renew the pistons
and rings. (7) Compression rings incorrectly installed. Oil
rings clogged or broken: Renew the piston rings.
NOTE: Before checking the engine for oil
leaks the engine should be completely de-
greased and cleaned. Run the engine at
operating temperature for a period and
visually check for oil leakage. By placing
white paper on the floor directly beneath the
engine any excessive leak can be readily
pinpointed.

Damaged or worn valve stem oil seals
which allow oil to be drawn down past the
valve stems into the combustion chambers
can be diagnosed by allowing the engine to
idle for a few minutes and then opening the
throttle. If oil is being drawn past the valve
stems a heavy discharge of blue smoke will
be seen at the tailpipe.

Piston, ring and cylinder bore troubles are
normally accompanied by a loss of compres-
sion. Cylinder compression can only be
accurately assessed by using a compression
gauge.

Run the engine over white paper to check for oil leaks.