1968 DATSUN 510 check engine

COOLING
SYSTEM
89

FAN
CLUTCH

Fan
Clutch

Operation
and

Inspection

Figure
6
shows
a

typICal
fan
clutch
dISas

sembled
Check
the
umt
whenever
the
water

pump
IS
removed
or
whenever
troubles
are

suspected
m
the

assembly
OperatIon
of
the
fan

clutch
should

be
observed
when
the
vehIcle
is

at

nmning

temperature

Operation
plate
Dust
cover
Drum

o9
Q

SpIder
assembly
LIning

CD

1
Warm

up
the

engme

2
MaIntam

engIne
speed
at
2
500

rpm

3

Usmg
a
thermometer
measure
the

temper

ature
close
to
the
fan
clutch

assembly
on
the

fan

4
The
clutch
should

engage
when
the

temp

erature
reaches
17

degrees
F
65

degrees
C

Conversely
the
clutch
should

deenergIze
when

the

temperature
drops
to
97

degrees
F
54
de

grees
C

5
Take
the
measurements
at
least
twice
SInce

the
thermostat
has
somewhat
of
a
tlme

lag

6
If
the
fan
clutch
falls
to

operate
properly
It

should
be
dIsassembled
and
servIced

Fan
Clutch

Disassembly

1
Follow
the
mstructIons
as

prevIOusly
gIven
to

remove
the
fan
and
clutch

assembly
from
the

water

pump

2
Refer
to
the

appropnate
exploded
illustratIon

for

your
model
and

to

Figure
7
which
shows
a

typiCal
fan
clutch

assembly

3
DIsassemble
unit
and

mspect
all

parts
for

signs
of
wear
or

breakage

4
To
check
the

operatIon
of
the
fan
clutch

thermostat

submerge
the

operatIon

plate
With

the
thermostat
In
hot
water
of
126

degrees
F

70

degrees
C
for
two
to
three
mmutes

Replace

if

It
faIls
to

operate

5
Assemble
the

fan
clutch
m
the
reverse
order

o

dIsassembly
THERMOSTAT

The

system
thermostat
IS
located
inside
the

water
outlet
elbow
on
the

upper
left
hand

por

bon
of
the

cylInder
head
The

temperature
sens

Ing
deVice

IS
threaded
Into
the
base
of
the
therm

ostat

housmg
and
IS
connected

electrlcally
to

the

temperature
gauge
WIthIn
the
vehIcle
dash

board

The

wax

pellet
m
the
thermostat

expands

when
heated
and
contracts
when
cold
The

pellet

IS
connected

through
a

pIston
to

a
valve

Expan

sion

pressure
IS
exerted

agalUst
a
rubber
dIa

phragm
which
forces
the
valve
to

open
and

per

rrut
coolant
to
flow

through
the
entIre

system

As
the

pellet
cools
contractIOn
allows

a

spnng

to
close
the
valve

Thermostat
Removal

1

Open
the
draIn
cock
on
the
bottom
of
the

radiator
and
dram
out

enough
coolant
so
that

the
level
In
the
radIator
IS
below
the
bottom
of

the

upper
radIator
hose

2
DIsconnect
the

upper
radIator
hose
from
the

water
outlet
elbow

3
Remove
the
two
nuts

holdIng
the
water
outlet

elbow
to
the
thermostat

housmg

4
Remove
the

gasket
and
thermostat
from
the

housmg
as
shown
m

FIgure
7

Thermostat

Inspection
and

Replacement

Submerge
the
thermostat
In
a

pan
of
water

Heat
the
water
and
momtor
the

temperature

2
The
thermostat
should
start
to

open
at

1796
1
27

degrees
F
82
1
1
5

degrees
C
Max

Imum

opemng
should
occur
at
203

degrees
F
95

ENGINE
ELECI
RlCAL
SYSTEM
9S

@

@

4
Test
the
COIls
for
shorts

by
unsoldermg
the

connectIons
of
each
coIl
and

repeatlng
the
test

given
m

step
3
If

a
defectIve
coil
IS
found
It

must
be

replaced

BRUSHES
AND
BRUSH
LEAD
WIRE

1
Check
condItIon
of
the
brush
contact
surface

and

general
wear
of
the
brush
If
the
brush
is

worn
to
under
02362
In

60mm
m

length

replace
It

Inspect
all
connectIons

carefully
for

looseness

or
cracks

Replace
or

reparr
as
re

qUIred

2
Check
the
connectIon
of
the
lead

clIp
and

WIre

3
Check
brush
holders
and

sprmg
clIps
for

damage
Replace
1f

they
will
not
hold
the
brushes

agaInst
the
commutator

properly
Clean
all

brushes
aIld
brush
holders

thoroughly

4
Check
brush

sprmg
tenSIon
WIth
a

spnng

scale
as
shown
m

Figure
14
The

reading
should

be
1
76
Ibs
0
8

kg
Replace
the

spnng
if
the

tenSIon
IS
under
1
54
Ibs
0
7

kg
@

ARMATURE
ASSEMBLY

1
Check
external

appearance
of
the
armature

and
commutator

2
Use
a

dIal

gauge
Figure
15
to
measure
the

armature
shaft
for
bend

Replace
the
armature

shaft
1f
the
bend
exceeds
0
001
in
0
08mm

@

3

Inspect
the
commutator
If
the
surface
IS

rough
sand

It
With
No
500

emery
paper
untIl

smooth
Use
a
dIal

gauge
to
check
the

commu

tator
If
out
of
round

IS
more
than
00079

In

0
2mm
or
the

depth
of
the

Insulatlng
mica
is

less
than
0
0079
In
0
2mm
from
the
commu

tator
surface
the
commutator
should
be
turned

on
a
lathe
Out
of
round
should
be
less
than

o
0020
in
0
05mm

Insulatmg
mica

should
be

undercut
as
shown

m

Figure
16

to
a

depth
of

from
0
0197
to
0
0315
in

0
5
to
0
8mm

4

Inspect
the

soldered
connectIon
of
the

arma

ture
lead
and
the
commutator
If
the
connection

is
loose
resolder
It

5

Usmg
a
clrcmt
tester
test
the
armature
for

ENGINE
ELECI
RlCAL
SYSTEM
97

No
Load
Lock

Torque
Test

1
Connect
the
starter
motor
in
series
with

a

12
volt

battery
and
antmeter
as
shown
in

Figure

19
The
antmeter
should
be

capable
of

mdIcatIng

1
000

amps

@
Switch

Voltmeter
Ammeter

2
Use

torque
testlng
equipment
to
determine

the

torque
the
motor

develops

3
Connect
a
voltmeter
and
a
vanable
resistor

WhICh
IS
used
to

regulate
the

voltage
Into
the

circwt

4
Close
the
sWitch

and

regulate
the

voltage
as

reqUIred
Figure
20

proVIdes

power
voltage

amperage
and

torque
mformatIon

that
1f
fol

lowed
will
mdIcate
the
condItion
of
the
starter

motor

Power
kw

Voltage
v

@

Test

Diagnosis

1
Low

speed
with

high
current
draw

might
re

sult
from

tIght
dirty
or
worn

bearings
bent

armatlIre
shaft
loose
field
call
or
a
shorted

armatlIre

2
Fatlure
to

operate
With

htgh
current
draw

may
result
from
a

gromlded
or

open
field
coil
a
defectIve
armature
coll
or
a
burned

out
com

mutator
bar

3
Low

torque
low
current
draw
and

low

speed

would
be
caused

by
hIgh
Internal
reSIStance
due

to
loose
connectIons

dirty
commutator
defec

tIve
leads
and

a
burned
out
commutator
bar

4

HIgh
speed
With
low

torque
would
be
caused

by
a

grounded
field
coll

Magnetic
Switch

Assembly
Test

H
the
above
tests
are

satIsfactory
check
the

magnetIc
SWitch

assembly
as
follows

1
Connect

Jumper
cables
between
the

negative

battery
tennmal
and
the
starter
motor
M
term

inal

as
shown
In

Figure
21
Also
connect
the

positIve
battery
terminal
to
the
S
terminal
and

place
a
SWitch
m
senes
in
the
CIrCuit

@
Ignition
switch

9

I

i
j

Battery
Starter
motor

rr

2
Close
the
SWitch
and
measure
the

dimension

given
m

Figure
22
The
dimensIon
should
be
as

specIfied

o
0591m

15mm

ENGINE
ELECTRICAL

SYSTEM

103

2
Check
the
lead

Wires
of
the
armature
coil

Includmg
the

neutral
wire

for

ground
as
shown

In

Figure
42

HIgh
reSIStance
no
current
flow

indicates

gqod
condItion

If

not
the
stator
must

be

replaced

DIODE

INSPECTION

The
diodes
can
be

inspected
through
the
use

of
a

lamp
and

battery
or
with

a
tester
The

lamp

and

battery
test
can
be
made
Without

disassembl

ing
the
alternator
wh1le
the

tester
should
be
used

when
the
dIodes

are

dIrectly
acceSSIble

1
Positive
Dwde
Test
Connect

the

battery

negative
terrmnal
WIth
the

connector
A
terrmnal

WhIte
and
the

battery

pOSItIve
terminal
With

the
connector
N

terrmnal

yellow
as
shown

m

Figure
43
The

lamp
m
the
circuit
should

hght

@

Reverse
the
connection
as

shown
m

Figure
44

If
the

lamp
does
not

hght
the

pOSItIve
diodes

are

satisfactory
If
the

lamp
does

light
one
or

all
of

the

pOSItIve
dIodes

are
defective
and
must

be

replaced
@

Qg

2

Negative
DIOde
Test

Connect
the

battery

negatIve
termmal
to

the
connector
N
terrmnal

yellow
and
the

battery

pOSItIve
termInal
to
the

connector
E
termmal

black
The

lamp
m
the

CIrcUit
should

lIght
Reverse

the
connectIons
If

the

lamp
does

not

lIght
the

nega1
ve
dIodes
are

satlsfactory
If
the

lamp
does

lIght
one

or
all

I

of
the

negatIve
dIodes

are
defectIve
and
must
be

replaced

To
test
the

indiVIdual
dIodes
With
a
tester

proceed
as
follows

1
There

are
two
kInds
of
diodes
as
shown
m

Figure
45
Check
dlOd
reSIstance

usmg
a
tester

In
both
dIrectIons

as

jl
own
in

Figure
46

f

Current
flow
@

Current
flow

re

ack

flgUre

e

terminal

r

Positive
diode

Negative
diode

@

106
CHAPTER
NINE

@

Igmtlon
switch

IgnItion

plug

engine

Condenser

IgnItIon
cod

@

II

9

ft

O

CHECKING
AND
ADJUSTMENT
foreIgn
matenal
or
cracks
Qean
the

cap
thor

oughly
Replace
it
If
cracks
are
found

Inspect

the

hIgh
tensIon
cables
to
see
that
all
connectIons

are

firmly
made
and
that
the
cables
are
not

cracked

Replace
any
defective
cables
Do
not

try
to

tape
or
mend
them
Cap
and
Rotor
Head

The

cap
and
the
rotor
head
must

always
be

kept
clean

to

prevent
lugh
voltage
leaks

Inspect

the

cap
penod1cally
for

SIgnS
of
carbon

bwldup

CHAPTER
TEN

EMISSION

CONTROL
SYSTEM

ThIs

chapter
covers
emission

control
and

exhaust

systems
The
emission

devices
used
in

clude
crankcase
ermssion

controls
an
exhaust

ermssion

system
and

evaporative
emission
con

trols

EXHAUST
EMISSION

CONTROL
SYSTEM

Two
methods
of
exhaust
emission

control
are

used

on
the
Datsun

One
is

an
aIr

injection

system
the
other
consists

of

engine
modifica

tIons
Datsuns

were

equipped
With
the
air

injec

tIon

system
only
through
1970
SInce
then
all

models

have
combined
aIr

mjection
with

engine

modIficatIons
EmisSIon

servicing
IS

complex

and

should
be
left
to

qualIfied

professionals

Figure
1

Illustrates
the

system
used

through

model

year
1969

Figure
2
IS
the

system
used

after
1970

Figures
3

through
7
offer
detaIls
of

various

emission

components

Maintenance
and

Testing

Penodlc

mspection
and
service

should
be

done

every
12
months

or
12
000
miles
The

engine
must
be

in

good
working
order
to
main

tain

a
low

level
of
harmful
emissions
There

fore

perform
a

general
tune

up
as

spec1fied
in

Chapter
Four
before

followmg
the

procedures

below
CRANKCASE
EMISSION

CONTROL
SYSTEM

The
crankcase

emission
control

system
is

shown
in

FlgDre
8
It
IS
a
closed

system
that

pre

vents
crankcase

gases
from

escaping
to
the
at

mosphere

Blowby
gases
are
dIrected

to
the

intake

manifold

through
the
ventilation

control

valve

Normally
capacity
of
the

valve
is

suffi

cient
to
handle
the

blowby

gas
plus
a
small

amount
of

ventIlating
air
drawn
from
the

air

cleaner

through
a
tube

leading
to
the
crankcase

Under
fun

throttle
condItIons
manifold
vacuum

is

Insufficient
to
draw
the

blowby
through
the

valve
When
this

happens
b10wby
flows

through

the

system
In
the
reverse
dIrection

General

1
Start
the

engine
and

bring

up
to

operating

temperature

2
Check

hoses
and
hose
connections
for

leaks

3

Examine
the
hoses
for

signs
of

cracks
or
de

terioraoon

Replace
as

required

Crankcase

Ventilation

Control
Valve

1
Start
the

engme

2
Remove

the
ventIlator
hose
from
the
crank

case
ventilatIon
control
valve
A

htssmg
nOISe

EMISSION

CONTROL
SYSTEM
117

ENGINE
EMISSION
CONTROL
COMPONENTS

CD

1
Relief
valve

2
Air

pump

3
Check

valve

4
Anti
backfire

valve

AIR
INJECTION
SYSTEM

CD

SILENCER

CHECK
VALVE

NOZZLE

c

122

CHAPTER
TEN

1
Start
the

engIne
and

bnng
It

up
to
normal

operatIng
temperature

2

Inspect
all
hoses
and
connectIons
for
leaks

and
detenoratIon
Shut
off
the

engme
Replace

any
defectIve
hoses

3
Remove
the
hose
attached
to
the
check

valve

4

VIsually
Inspect
the

posItIon
of
the
valve

plate
InsIde
the

valve

body
See

Figure
10
It

should

be

lIghtly
posItIoned
agaInst
the

valve

seat

away
from
the
aIr
dlstnbutor
manifold

5
Insert
a

probe
Into
the
valve
connectIon
on

the
check
valve

Depress
the
valve

plate
It

should
return

freely
agaInst
the
valve
seat
when

released

6
Leave
the
hose
dISconnected
and
start
the

engme

7

Slowly
Increase

engine
speed
to
1
500

rpm

Watch
for
exhaust

gas
leakage
at
the
check

valve
There
should

not
be

any
The
valve

may

flutter

or
VIbrate
at
Idle

speeds
ThIS
IS
normal

Replace
the
valve
u

defecuve

Anti
Backfire
Valve

1
Start
the

engme
and

bnng
to

operating

temperature

2

Inspect
all
hoses
and
hose
connectIons
for

leaks
and
detenoratIon

Replace
as

required

3
DIsconnect
the
hose
at
the
antI
backfire

valve

leading
to
the
Intake

manuold
Insert
a

plug
ill

the

hose
and
fasten

securely

4

Open
and
close
the
throttle
valve

rapidly
See

Figure
11
Place
a

finger
over
the
valve
outlet
to

the

m
take
manuold
If

arr
flow
IS
felt
for

one
to
two
seconds
the
valve
IS

functIonIng

properly

If
there
s
no
aIr
or
If
the
flow
is
felt
for
more

than
two
seconds
the
valve
IS
defectIve
and
must

be

replaced

5
Connect
the
alr
hose
to
the
mtake
manuold

after

remOVIng
the

plug

6
DIsconnect
the
aIr
mlet
hose
from
the
air

pump
at
the
antI
backfire
valve
If
the

engine

Idle

speed
changes
excessIvely
the
valve
is
de

fectIve
and
must
be

replaced

Air

Pump

1
Check
the
atr

InjectIon
pump
belt
tension

DeflectIon
of
the
belt
should
be
0
5
In
when

pushed
In

by
thumb

pressure
Adjust
belt
u

necessary

2

Operate
the

engme
untIl
normal

temperature

IS
reached

3

Inspect
all
hoses
hose

connectIons
and
the

arr

gallery
for

SIgnS
of

leaks
or
detenoratIon

Replace
as

required

4
DIsconnect
the
air

supply
hose
at
the
check

valve

5
Insert
the

open
pipe
end
of
a

pressure
test

gauge
adapter
Into
the
air

supply
hose
See

Fig

ure
12

Clamp
the

adapter
firmly
to
the
hose

Install
the

pressure
test

gauge
to

the

adapter

PosItIon
the

adapter
and
test

gauge
so
that
the

alr
blast
emitted

through
the
dnlled

pipe
plug

Will
be

harmlessly

dislppated

6
Install
a
tachometer

on
the

engme
WIth
the

engIne
speed
set
to

1
500

rpm
observe
the

pres

sure

readmg
AIr

pressure
should
be
0
47
m

Hg

16mm
Hg