1977 DATSUN PICK-UP spark plugs replace

p

r

ET002

Fig
E1
11

Checking
specific
gravity

of
bottery
electrolyre

Clean

top
of

battery
and
terminals

with
a
solution
of
bakin

soda
and

Pennissible

value

Frigid
climates
Over
1

22

Tropical
climates

lOver
1
18

Other
climates

lOver
1
20

CHECKING
AND

ADJUSTING

IGN

ITIONTIM
iNG

AD
IUSTING
IGNITION

TIMING

I
Check

spark
plugs
and
distributor

breaker

points
for
condition

2

Thoroughly
remove
dirt
and
dust

from

timing
mark
on
crank

pulley
and

timing
indicator
on
front
cover

3
Warin

up
engine
sufficiently

4
Imtalla
timing
light
on
No
I

cylinder
spark
plug
wire
and
install
a

tachometer

5
Set

idling
spero
toapproxintate
y

750

rpm

6
Check

ignition
timing
with
a

timing
light
if
it
is

specified
value

If

necessary

adjust
it

as
follows

1
Loosen
setscrew
until
distribu

tor

can
be
moved

by
hand

2

Adjust
ignition

timing
to

speci

fied
value

3
0
Lock
distributor
setscrew

ai1d

make

sure
that

timing
is
correc
Engine
Tune

up

water

Rinse
off
and

dry
with
com

pressed
air

Top
of

battery
must
be

clean
to

prevent
current

leakage
be

tween
terminals
and
from

positive

terminal

to
hold
down

clamp

In
addition
to
current

leakage
pro

longed
accumulation
of
acid

and
dirt

o
n

top
If
l

l
ry
may

ca
u
iCbli
t

rj
I
g

of
the
material

covering
connector

straps
and
corrosion
of

straps
After

tightening
terminals
coat
them
with

petrolatum
vaseline
to

protect
them

from
corrosion

Full

charge

value

at
200C
680F

1
28

1
23

1
26

oo

I

ET169

Fig
ET

13

Checking
ignition
timing

Ignition

timing

Manual
transmission

120
750

rpm

Non
California
models

100
750

rpIll

California
models

Automatic
transmission

120

650

rpin

in

0

position

ET
10
CHECKING

ANb

REPLACING

SPARK

PLUG

I

Remove

and
clean

plugs
in

a
sand

blast
cleaner

2

Inspect
insulator
for
cracks
or

chips

3

Check
both
center
and

ground

electrodes

If

they
are

excessively
worn
re

place
with
new

spark

plugs

4

Spark
plug
gap

Breaker

points

type

0

8
to
0
9

mm

0
031
to
0
035
in

Transistor

ignition

type

1
0

to
1
1

mm

0
039
to
0
043
in

Tightening

torq

1
5
to
2
0

kg
m

11
to
A4
ft
lb

Fig
ET
14

Checking

spark
plug
point

gap

CHECK
I
G

DISTRIBUTOR

OPERATING

PARTS

AND

1

lrI9N

WIRING

BREAKER

POINTS

Non

California
models

Check
the
distributor
breaker

points
for
abnonnal

pitting
and
wear

Replace
if

necessary
Make
sure

they

are

properly

aligned
and
that

point

dwell

and

gap
are
correct
Clean
and

apply
distributor

grease
to
the
carn

lobes

Note
00

not

apply
grease
excessively

Point

gap

0

45
to
0
55
mm

Om8
to
0
022

in

Owell

angle

49
to
55

degrees

EE322

Fig
ET
15
Checking
diltribu
tor

point

gap

AIR
GAP

California
models

For

inspection
procedures
and

reference
data
refer

to
the

topic
Air

Gap
in

Section
EE

page
EE
29

DISTRIBUTOR

Check

centrifugal
advance
unit
for

loose
connection
or

improper
opera

tion
If
it
is
not

operating
properly

the

problem
may
be

due
to
a

sticky

spring
or
excessively
worn

parts
This

operation
needs
a
distributor
tester

For

inspection
procedures
and

ref

erence
data
refer
to

relative

topic

under
Distributor
in

Section
EE

If
vacuum
advance
mechanism
does

not

properly
operate
check
for
the

following
items
and

correct
the

prob

lem

as

required

1
Check
vacuum
inlet
for

signs
of

leakage
at
connection
If

necessary

retighten
or

replace

2

Check
vacuum
diaphragm
for
air

leak

If

necessary
replace
diaphragm

3

Inspect
breaker

plate
for
smooth

movement

If

plate
does
not
move
smoothly

this
condition
could
be
due

to

sticky

steel
balls
If

necessary
replace
break

er
plate
assembly

IGNITION
WIRING

Use

an
ohmmeter
to
check
resist

ance
of

secondary
cables
Disconnect

cables
from

spark

plugs
and
install
a

proper
adapter
between
cable
and

spark
plug
Remove

distributor
cap

and
secondary
cables
as
an

assembly

Do
not
remove
cables
from

cap

Check
resistance
of
one
cable
at
a

time

Connect
ohmmeter
between

spark

plug
adapter
and

corresponding
elec

trade
inside
cap
If
resistance
is
more

than
30
000
ohms
remove
cable
from
Engine
Tune

up

cap
and
check
cable
resistance

only
If

resistance
is
still
more
than

30
000

ohms

replace
cable

assembly

EF125

Checking
high
tension

cable

CHECKING

DISTRIBUTOR
CAP

ROTOR
AND

CONDENSER

Note
This

operation
is

to
be

per

formed
while

checking
distributor

points
Inspect
distributor

cap
for

cracks
and

flashover

External
surfaces
of
all

parts
of

secondary
system
must
be
cleaned
to

reduce

possibility
of

voltage
loss
All

wires
should
be
removed
from
distrib

utor

cap
and
coil
so
that
terminals

can

be

inspected
and
cleaned
Burned
or

corroded
terminals
indicate
that
wires

are
not

fully
seated
which

causes

arcing
between
end
of
wire
and
ter

minal
When

replacing
wires
in

ter

minai
be

sure
they
are

fully
seated

before

pushing
rubber

nipple
down

over
tower
Check
distributor
rotor
for

damage
and
distributor
cap
for

cracks

CONDENSER

I
Clean

outlet
of
condenser
lead

wire

and
check
for

loose
setscrew

Retighten
if

necessary

2
Check

condenser
with
a
con

denser
tester

Condenser

capacity

0
20
to
0
24

IF

Micro
Farad

Condenser
insulation
resistance

5Mn

Mega
ohms

ADJUSTING

CARBURETOR
IDLE

RPM
AND
MIXTURE

RATIO

Cautions

a
On
automatic
transmission

equip

T
11
ped
models
check
should
be

per

fonned
in

the
D

position

Be
sure

to

engage
parking
brake
and

to
lock
both
front
and
rear

wheels

with
wheel
chocks

b

Keep
your
foot
down
on
the
brake

pedal
while

depressing
the
accelera

tor

pedal
Otherwise
vehicle

surges

forward

dangerously

Notes

a
Do
not

attempt
to
screw
the
idle

adjusting
sc
ew
down

completely

Doing
so
could
cause

damage
to

tip

which
in

turn
will
tend
to
cause

malfunctions

b

If
idle
limiter

cap
obstructs

proper

adjustment
remove
it

To
install
idle
limiter

cap
refer
to

Idle
Limiter

Cap

c

After
idle

adjustment
has

been

made
shift
the
lever
to
the
N
or

P

position
for
automatic
trans

mission

d
When

measuring
CO

percentage
in

sert

probe
into

tail

pipe
more
than

40
em
15
7
in

CO
idle

adjustment
with

CD
meter

Idle
mixture

adjustment
requires

the
use
of
a

CO
meter

especially
for

California
models
When

preparing
to

adjust
idle
mixture
it
is

essential
to

have
the
meter

thoroughly
warmed

up

and
calibrated

I
Check
carburetor

pipes
for

proper

connection

2

Warm

up
engine
until
water
tem

perature
indicator

points
to
the
middle

of

gauge
The

procedure
to
warm

up

engine
is
not

specifically
recom

mended
Either

driving
vehicle
or

oper

ating
engine
at

no
load
will
be

good

3
Make

sure
that
water
tempera

ture
indicator

points
to

the
middle

Further

keep
engine
running
at
about

2

000

rpm
for
about
5
minutes
with

out

applying
load
to

engine
in

order
to

stabilize

engine
condition
Engine

hood
should
be

open

4
Run

engine
for

about
10
minutes

at
idling
speed
During
this
10

minutes

proceeq
as
described
i

steps

5

to
9
below

5
Remove
air
hose
between
3

way

connector
5

way
connector
for
Cali

fornia
models
and
air

check
valve
as

shown
in

Figure
ET
17

Plug
the

dis

Condition

ENGINE
POWER
NOT

UP
TO
NORMAL

Low
compression

Ignition
system
out
of

order

Fuel

system
out

of

order

Air
intake

system
out

of
order

Emission
control

Overheating

O

cooIing

Others
Engine
Tune

up

Probable
cause

Incorrect

iSnition
timing

Damaged

spark
plugs

Worn
distributor

points

Malfunction
of
choke

system

Clogged
fuel

pipe
or

floating
valve

Dirty
or

clogged
fuel
strainer

Fuel

pump
will
not
work

properly

C10ssed
carburetor

jets

Malfunction
of
altitude

compensator

CIOJBed
air
cleaner

Ail

inhaling
from
manifold

gasket
or

carburetor

gasket

Malfunction
of

E
G
R
valve

Stick
E
F
E

valve
shaft

Insufficient
coolant

Loose
fan
belt

Worn
or
oiled
fan
belt

Inoperative
thermostat

Worn
water

pump

Clogged
or

leaky
radiator

Worn
radiator
filler

cap

Ail

in

cooling
system

Improper
engine
oil

grade

Incorrect

ignition
timing

Clossed
carburetor
lean
mixture

Disconnected
altitude

compensator
hOlle

Inoperative
thermostat

Improper
octane
fuel

L

j
tire

pressure

Dragging
brake

Clutch

slipping

ET

30
Corrective
action

Previously
mentioned

Adjust

Clean

adjust
or

replace
plull

Dress

or

replace
points
Also
check

condenser

Adj
lst

Clean

Replace

Repair
or

replace

Disassemble
and
clean

Check
and

replace

Replace
element

Replace
gasket

Check
and
replace

Repair

Replenish

Adjust
fan
belt

Replace

Replace

Replace

Flush

repair
or

replace

Replace

Retighten
each

part
of

cooling
system

Replace
with

proper
grade
oil

Adjust

Overhaul
carburetor

Connect

Replace

Replace
with

specified
octane
fuel

Inflate

to

specified

pressure

Adjust

Adjust

Except
transistor

ignition
system

Condition

ABNORMAL

COMBUSTION

backfue
afterflre

run
on
etc

Improper

ignition
timing

Fuel

system
out
of

order

Faulty
cylinder
head
etc

Others

EXCESSIVE
OIL

CONSUMPTION

Oilloak

Excessi
lo
oil

consumption

Others
Engine
Tune

up

probable
cause

Improper
ignition
timing

Improper
heat

range
of

spark
plugs

Damaged
carburetor

or
manifold

gasket

backfue
afterfire

Clol
l
ed
carburetor

jet

Improper
function
of

the
float

Uneven

idling
Run
on

Improperly
adjusted
B

C
D
D

set

pressure

Malfunction
of
anti

dieseling
solenoid
valve

Malfunction
of
auio
choke

Improperly
adjusted
valve
clearance

Excess
carbon
in

combustion
chamber

Damaged
valve

spring
backfire
afterflre

Malfunction
of

A
T
C

air
cleaner

Inoperative
ariti
backfue
valve

Loose
oil
drain

plug

Loose

or
damaged
oil

pan
gasket

Loose
or

damaged
chain
cover

gasket

Worn
oil
seal
in
front
and
rear
of
crankshaft

Loose
or

damaged
locker
cover

gasket

Improper
tightening
of
oil
filter

Loose
or

damaged
oil

pressure
switch

Cylinder
and

pioton
wear

Improper
location
of

piston
ring

gap
or

reversely
assembled

piston
ring

Damage
piston
rings

Worn

piston
ring
groove
and

ring

Fatigue
of
valve
oil
seal

lip

Worn
valve

stem

Inadequate
quality
of

engine
oil

Engine
overheat

ET32
Corrective
action

Adjust
ignition
timing

Use

specified
spark
plugs

Replace
them
with
new

parts

Disassemble
carburetor
and
check
it

Adjust
the
level
and
check
needle
valve

Adjust

Adjust

Check
or

replace

Adjust

Adjust

Remove
head
and

get
rid
of
carbon

Replace
it
with
a
new
one

Check
for
loose
vacuum
hoses

Replace
if

necessary

Replape

Tighten
it

Renew

gasket
or

tighten
it

Renew

gasket
or

tighten
it

Renew
oil
seal

Renew

gasket
or

tighten
it
but
not
too

much

Renew

gasket
and

tighten
it
with
the

proper

torque

Renew
oil

pressure
switch
or

tighten
it

Overhaul

cylinder
and
renew

piston

Remoun
t

piston
rings

Renew

rings

Repair
or
renew

piston
and

cylinder

Renew

piston
and

piston
ring

Replace
seal

lip
with
a

new
one

Renew
valve
or

guide

Use
the

designated
oil

Previously
mentioned

NON
CALIFORNIA
MODELS
Engine
Electrical

System

IGNITION
CIRCUIT

CONTENTS

EE
26

CALIFORNIA
MODELS
EE
2B

NON

CALIFORNIA
MODELS

The

ignition
circuit
consists

of
the

ignition
switch
coil

distributor

wiring
spark
plugs
and

battery

The
circuit

is

equipped
with
a

resistor

During
cranking
electrical

current

bypasses
the
resistor

thereby

connecting
the

ignition
coil

directly
to

battery
This

provides
full

battery

voltage
available
at
coil
and

keeps

ignition

voltage
as

high
as

possible

The

low

voltage
current
is

supplied

by
the

battery
or

alternator
and

flows

through
the

primary
circuit

It
consists

of
the

ignition
switch
resistor

primary
winding
of
the

ignition
coil

distributor
contact

points
condenser

and
all

connecting
low
tension

wiring

The

high

voltage
current
is

pro

duced

by
the

ignition
coil

and
flows

through
the

secondary
circuit
result

ing
in

high

voltage
spark
between
the

electrodes
of

the

spark
plugs
in

engine

cylinders
This
circuit
contains

the

0
cl

Battery

Ignition
coil
secondary
winding
of

the

ignition
coil

high
tension

wiring
distributor
rotor

and

cap

When
the

ignition
switch
is

turned

on
and
the

distributor
contact

points

are
closed

the

primary
current

flows

through
the

primary
winding
of
the

coil
and

through
the

contact

points
to

ground

When
the

contact

points
are

opened

by
the

revolving
distributor
earn
the

magnetic
field
built

up
in
the

primary

winding
of
the

coil
moves

through
the

secondary
winding
of
the

coil

inducing

high
voltage
The

high

voltage
is

produced

every
time

the

contact

points

open
The

high
voltage
current

flows

through
the

high
tension
wire

to
the
distributor

cap
Then
the
rotor

distributes
the
current
to

one
of
the

spark

plug
terminals
in
the
distributor

Re5istor

To

starter

Secondary

winding

Cap

Breaker

point

f

Distributor

EE
26
cap

Then
the

spark
obtains
while
the

high
voltage
current

jumps
the

gap

between
the

insulated
electrode
and

the

ground
side
electrode
of
the

spark

plug
This

process
is

repeated
for
each

power
stroke
of

the

engine

The
distributor
contact

point
and

spark
plugs
should
be

inspected
clean

ed

and

regapped
at

tune

up
They

should
also
be

replaced
periodically
as

specified
in

the
Maintenance

Sched

ule
In

addition

apply
grease
NLGl

consistency
No
I

containing

MoS2
or

equivalent
to
distributor

shaft
and

grease
MIL
G
l0924B

containing

MoS2
or

equivalent
to
cam
as
reo

quired

The
remainder

of
the

ignition

component

parts
should
be

inspected

for

only
their

operation
tightness
of

electrical
terminals
and

wiring
con

dition

The

ignition
circuit
is
shown
below

IR

IB

I

is
21

J
g

Rotor

head

EE060

Fig
EE

53

Ignition
ydem
circuit

diagram

Primary
winding

1

Ignition
coo

I

Secondary

winding
CALIFORNIA
MODELS

The

ignition
circuit

consists
of

igni

tion

switch
transistor

ignition
unit

distributor

wiring
spark

plugs
and

battery

The

distributor
is
of
the
contactless

type
and
is

equipped
with
a

pick
up

coil
which

electrically
detects
the

igni

tion

timing

signal
in

place
of
the

circuit

breaker
of
the
conventional

distributor
The
transistor

ignition
unit

is
a
new
addition
which

generates
the

signal
required
for
the
make

and
break

of
the

primary
electric
current
for
the

ignition
coil

The
circuit
is

equipped
with
a

resistor

During
cranking
electrical

current

bypasses
the

secondary
resis

tor

thereby
connecting
the

ignition

coil

through
the

primary
resistor
This

makes

battery
voltage
available
at
ef

ficiently
and

keeps
ignition
voltage
as

high
as

possible

The

primary
resistor

selVeS
to

pro

tect
transistor

ignition
circuit

The
low

voltage
current
is

supplied

by
the

battery
or
alternator
and
flows

through
the

primary
circuit

It
consists
of
the

ignition
switch
Engine
Electrical

System

resistor

primary
winding
of
the

igni

tion

coil
transistor

ignition
unit
and

all

connecting
low
tension

wiring

The

high
voltage
current
is

pro

duced

by
the

ignition
coil
and

flows

through
the

secondary
circuit

result

ing
in

high

voltage
spark
between
the

electrodes
of
the

spark
plugs
in

engine

cylinders

This
circuit
contains
the

secondary

winding
of

the

ignition
coil
distribu

tor

high
tension
wires
to
coil
and

spark
plugs
distributor
rotor
and

cap

When
the

ignition
switch
is
turned

on
and
the

distributor
reluctor
rotates

the

primary
current
flows

through
the

primary
winding
of
the

coil
and

through
transistor

ignition
unit
to

ground

When
the

prim

ary
circuit
is

opened

by
circuit

of
transistor

ignition
unit

the

magnetic
field

built

up
in
the

primary
winding
of
the
coil
moves

through
the

secondary

winding
of
the

coil

inducing
high
voltage
This

high

Battery
Primary
Secondary

I

Resistor

To

starter

r
Transis
tor

ignition

unit
I

I

Pick
up

rcoil

r
Rotor
head

nl

J
R5

U1f

1

Retuctor
r
oi

l
f
S

park

plugs
voltage
is

produced

every
time
the

primary
circuit

opens

The

high

voltage
current
flows

through
the

high
tension
wire
to

the

distributor

cap
then
the
rotor

distri

butor

cap
then
the

rotor
distributes

the

current
to

one
of

the

spark
plug

terminals
in

the
distributor

cap

Then
the

spark
occurs
while
the

high

voltage
current

jumps
the

gap

between
the
insulated
electrode

and

the

ground
side
electrode
of
the

spark

plug
This

process
is

repeated
for

each

power
stroke
of

the

engine

The

spark

plug
should
be

inspected

cleaned
and

regapped
at
tune

up

Spark
plugs
should
also
be

replaced

periodically
as

specified
in
the
Main

tenance
Schedule

The

remainder
of
the

ignition
com

ponent
parts
should

be

inspected
for

only
their

operation
air

gap
of

distri

butor

tightness
of
electrical
terminals

and

wiring
condition

Apply
grease

NLGI
consistency

No
I

containing
MoS
or

equivalent

to
distributor
rotor
shaft
as

required

EE287

EE
28
Fig
EE
55

Ignition

8Y3tem
circuit

diagram

Engine
Electrical

System

Transistor

ignition
unit

r
1
Power

switching

circuit
Duty

control

circuit

To
starter

To
distributor

Ba

ttery
Ignition
coil
1
Spark
timing

1
Signal
mom

toring
circuit
Lock

j
preven
ling

circuit

nm

Distributor

EE437

Fig
EE
75
Transistor

ignition
unit
circuit

diagram

REMOVAL
AND

INSTALLATION

Transistor

ignition
unit
is

located

on
the

right
hand
dash

side

panel
in

passenger
compartment

Disconnect

battery
negative
cable

2
Disconnect

wiring
harness
from

unit

3
Remove
two

setscrews
and
te

move
unit

4

To
install
reverse
the
order
of

removal

Note
Be

sure
to
connect

wiring
har

nesses
to
their

proper

positio

Failure
to
do
so
will

damage
the

unit

Refer
to

Figure
EE
76

Fig
EE
76
External
view

of

ignition

unit
INSPECTION

If
the

engine
does

not
run
due

to

faulty
ignition
system
check
the

igni

tion

system
as
follows

Check
for
a
cracked
distributor

rotor
or

cap
and
corroded
tenninals

Visually

inspect
high
tension
wires

for

condition
and
if

necessary
use
an

ignition
oscilloscope
or
a
circuit
tester

to
make

performance
checks
Check

spark
plugs
and

adjust
gaps
as
neces

sary

Replace
a

spark
plug
which

is
not

suitable
for
further
use
If
the

above

checks
cannot
correct
the

problem

check
the
entire

ignition
system
with

an

oscilloscope
or

a
circuit

tester

L
CHECKING
WITH
AN

OSCILLOSCOPE

An

oscilloscope
can
be
used
for

checking
almost

all
the
items
in

a

transistor

ignition
system

CHECKING
WITH
A

CIRCUIT

TESTER

A
circuit
tester
can
not
be

used
for

the

duty
control
circuit

and

power

t18nsistor

performance
tests

Both

methods
use
of

an

oscilloscope
and
a

circuit
tester

are
described
in
this

section

EE

37
The
items

are
classified

by
numerals

in

accordance
with
the

objective
of

checks
to

be

performed
Several

wiring

diagrams
are
found

on

pages
EE
41

to

EE
45
The
thick
lines
indicate

the

objective
of

each
individual
item

check

When

checking
a
circuit
with
an

oscilloscope
or
a
circuit
tester
be

careful
not
to

confuse
the

polarity
of

the
lead
wires
if

potential
difference

exists
between
the
check

points
at

which
the
lead
wires
are
to
be
con

tacted

Also
do
not

attempt
to
con

nect
the

lead
wires
to

any
points
in
the

circuit
other

than
those

designated

Careless

handling
of
the
lead
wires

will

result
in

damage
to
the
transistor

ignition
unit

as
well
as
to
the
oscillo

scope
or
circuit

tester

The
connection
of

a
tachometer

or

a

timing
light
in

parallel
with
an

oscilloscope
or
a
circuit
tester
is
al

lowable

provided
that
such
a

connec

tion
is

made
with
due
consideration
to

wiring
connections

1
POWER
SUPPLY

WIRING

AND

BAnERY
CHECK

See

wIrIng
diagram

In

FIgure
EE
88

Procedure

I
Turn
on

ignition
switch

2

Connect

a
circuit
tester
or

an

oscilloscope
as
shown
in
the

figure

below

DC
50
volt

range

EE302

Fig
EE
77

Checking
power
supply

wiring
and

batt

ry

Criterion

When

power
source

battery

voltage
is

indicated
OK

Lower

or
no
indication
N
G

DESCRIPTION

INSPECTION

CLEANING
AND
REGAP

DESCRIPTION

The

spark
plugs
are
of
the

conven

tional

type
having
14
mm
0

551
in

threads
The

spark
plug
gaps
are
1
0
to

1
1
mm
0
039
to
0
043
in
on
Cali

fomia
models
and
0
8

to
0
9
mm

0
031
to

0
035
in
on
non
California

models
The

inspection
and

cleaning

should
be
made
every
suitable
mainte

nance

period
If
necessary
replace

Note
All

spark

plugs
installed
on
an

engine
must
be

of
the
same
brand

and
the

same
number
of
heat

range

INSPECTION

L
Remove

spark
plug
wire

by

pulling
on

boot
not
on
wire
itself

2
Remove

spark
plugs

3

Check
electrodes
and
inner

and

outer

porcelains
of

plugs
noting
the

type
of

deposits
and
the

degree
of

electrode
erosion

Refer
to

Figure

EE
96

Normal
Brown
to

grayish
tan
de

posits
and

slight
electrode
wear

indicate
correct

spark
plug
heat

range

Carbon
fouled

Dry
fluffy
carbon

deposits
on
the
insulator
and

electrode
are

usually
caused

by

slow
speed
driving
in

city
weak

ignition
too
rich
fuel
mixture

dirty
air
cleaner
etc

It
is

advisable
to

replace
with

plugs

having
hotter
heat

range

Oil
fouled
Wet
black

deposits
indi

cate
excessive
oil
entrance
into

combustion
chamber

through
worn

rings
and

pistons
or
excessive
clear

ance
between
valve

guides
and

stems
If
the
same
condition
re

mains
after

repair
use
a
hotter

plug
Engine
Electrical

System

SPARK
PLUG

CONTENTS

EE
4B

EE
47

EE
47

EE
47
SERVICE
DATA
AND
SPECIFICATIONS

TROUBLE
DIAGNOSES
AND

CORRECTIONS
EE
4B

Overheating
White
or

light

gray
in

sulator
with
black
or

gray
brown

spots
and
bluish
burnt
electrodes

indicate

engine
overheating
More

over
the

appearance
results
from

incorrect

ignition
timing
loose

Normal

Overheating

EE079

4
After
cleaning
dress
electrodes

with
a
smaU
fine
file
to
flatten
the

surfaces
of
both
center
and
side

electwdes
in

parallel
Set

spark
plug

gap
to

specification

5
InstaU

spark
plugs
and

torque

each

plug
to
L5

to
2
0

kg
m

11
to
14

ft
Ib

6
Connect

spark

plug
wires

CLEANING

AND
REGAP

Clean

spark
plugs
in

a
sand
blast

type
cleaner
Avoid
excessive

blasting

Clean
and
remove
carbon
or
oxide

deposits
but
do
not

wear
away

porcelain
If

deposits
are
too
stubborn

EE
47
spark
plugs
low
fuel

pump
pres

sure

wrong
selection
of
fuel
a

hotter

plug
etc

It
is
advisable
to

replace
with

plugs

having
colder
heat

range

Ir

i

Carbon
fould

Worn

Fig
EE
96

Spark
plug

discard

plugs

After

cleaning
spark
plugs
renew

firing
surface
of
electrodes
with
me

mentioned
aboVe
Then

gap
spark

plugs
to

specified
values
with
a
round

wire
feeler

gauge
All

spark
plugs
new

or
used
should
have
the

gap
checked

and
reset

by
bending
ground
electrode

EEOBO

Fig
EE
97

Setting
park
plug
gap