compression ratio NISSAN PULSAR 1987 Workshop Manual

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.

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.