DATSUN B110 1973 Service Repair Manual

ENGINE

How
to
read

Figure
ET
22

Determining
operating

pressure
and

adjustment
of
vacuum
control
valve

1
When

atmospheric
pressure
is
known

operating

pressure
is
found

by
following
the

arrow
line
A

When
altitude
is
known

operating
pressure
is
found

by
following
the
arroW
line
B

2
Turn

the

adjusting
screw
of
the

vacuum
control

valve
See

Figure
ET
23
and

adjsut
the
vacuum

control
valve
so
that

negative
pressure
in
the
intake

manifold
is

suspended
for

a
few
seconds
at
the
value

of

operating
pressure
found

as
described
in
I
above

while
the

engine
speed
decreases
from
3

000
to

1

000

rpm

I
Vacuum

adjusting
screw

2
Vacuum
control
valve

3

Lock
screw
4
Throttle

opener

solenoid

5
Control
valve

assembly

Fig
ET
23
Vacuum
control
valve

II
When

engine
revolution
does

not
fall
to

tdling
speed

Intake
manifold

I
Throttle

opene
operating

I
vacuum
curve
when

racing

Operating

pressure

Idling

Engine
evolution

3
000
rpm
Notes
a
When

turning
the
vacuum

adjusting
scre
N
do

not

depress
the
screw

with
a
screwdriver

b
When

measuring
operating
pressure
be
sure
to

tighten
the
lock
screw
of
the
vacuum

control
valve

first

c
When

the
servo
diaphragm
does
not
draw
the

link
or

operating

pressure
is

high
vacuum
turn
the

vacuum

adjusting
screw
clockwise
When
the
servo

diaphragm
draws
the
link
at

idling
speed
or

operating
pressure
is
low
vacuum
turn
the
vacu

um

adjusting
screw
counterclockwise

Set
lock
screw

stationarily

repeat
the
above

described

adjustment
and
make

sure
that
tho

operating
pressure
is
correct
and
that
the

engine

speed
settles
down
at
the
rated

idling

speed

When

engine
revolution
does
not
CaU
to

idling

speed
See

Figure
ET
24

When
the

engine
revolution
does
not

fall
to

the

idling
speed
it
is

necessary
to
reduce

the

idling

negative
pressure
of
the
intake
manifold
lower

than

the

operating
pressure
of
the
throttle

opener
See

Figure
ET
24
case
of

Il
Il

I
When

engine
revolution
falls
to

idling
speed

Intake
manifold

I
Throttle

opene
operating

I
vacuun
curve

when

racing

No
load

No
load

Operating

pressure
I

I

I

I

I

I

I

I

I

Idling
Engine
revolution
3
000

rpm

Fig
EY
24

Characteristic
curves

of
throttle

opener

In

this
case
B
it
is

necessary
to

labour
the

engine

on
road
I
by
chassis

dynamometer
2

or
by

raising
rear
axle

by
stand
3

The
car
should
then
be
accelerated
from
64
to
80
kro
h
40
to

SO
MPH

in

top
gear
for
M
T
or

0

position
for
A

T
After

the
above

procedure
has
been

completed
the

ET
16

EMISSION

CONTROL
AND

TUNE
UP

accelerator

pedal
is

released

During
the

testing
measure
the
throttle

opener

operating
pressure
to
see
whether
it
is
in
the

predetermined
value
or
not
See

Figure
ET
25
Adjustment
is

exactly
the

same
as
that
in
the
case

I
When

engine
revolution
falls
to

idling
speed

Page
ET
14

Vacuum

gauge

Intake

man
fol

p

ci

J

v

1
Road
test
r

Vacuum

gauge

7I
t

i

2
Chassis

dynamometer
Vacuum

gauge

y

3
Raise

up
rear
axle

housing
by
stand

Fig
ET
25

Testing
operating
pressure

of
the
throttle

opener

when
fhe

engine
revolufion
does
not

lall
fo
fhe

idling
speed
II

J

3
Withdraw

cotter

pin
and
remove
link

4
Loosen
lock
nut
and
remove
servo

diaphragm

from
carburetor
Removal

When

replacing
the
control
valve

assembly
and

servo

diaphragm
observe
the

following

Control
valve

assembly
Vacuum
control
valve

throttle

opener
solenoid

1

Disconnect

vacuum
hoses

and
throttle

opener

solenoid
harness

from
the
unit

2

Remove

two
installation

bolts
J

@

cY

@
1

Servo
diaphragm

2
Lock
nut

3
Link
@

CV

@

EC017

4
Bracket

5

Stopper

6
Carburetor

1
Installation

bolts

2

Vacuum
control

valve

3
Vacuum
hose
4
Throttle

opener
solenoid

5
Control
valve

assembly
Fig
ET
2
7

Removing
servo

diaphragm

TRANSMISSION
CONTROLLED

VACCUM
ADVANCE

SYSTEM

Fig
ET
26

Removing
control
valve

assembly

This

system
provides
the

vacuum
advance

only
when

the

gear
is
in

the

top
4th

position
and
retarded

spark

timing
with
no

vacuum
advance
at
other

positions
for

complete
combustion

This

system
however
allows
vacuum
advance

during

the

warming
up
in

cold
weather
and

enswes

satisfactory

driving
performance
immediately
after

starting
the

engine
Servo

diaphragm

1

Disconnect
vacuum
hose
from
servo

diaphragm

2
Remove

servo

diaphragm
together
with
carbu

retor

ET
17

ENGINE

Gear
Vacuum
advance
Note

R
No

1st
No

2nd
No

3rd
No

4th
Yes
Immediately
after

starting
the

engine
in
cold

weather
vacuum
advance
is
available

for
all

gear

positions

A12

Engine
with
Manual
Transmission

Distributor

Ignition
switch

8

1

J
Battery
Thermo
switch

9

Transmission

L

r
l

r
Vacuum
advance
unit

To
carburetor

Needle

valve

OFF

l
To
air
cleaner

ON

Vacuum

cutting
valve

solenoid

Top
switch

Top
off
I

7
1

OFF
Vacuum
actuated

ON
Vacuum
eminated

into

atmosphere

Fig
ET
28

Schematic

drawing
of
transmission
controlled
vacuum

advance

system

When

electric
current
flows

through
the

vacuum

cutting
valve

solenoid
the
needle
valve

opens
and
intro

duces
air
from
the
air
cleaner
into
the
vacuum
advance

unit

of
the
distributor

through
the

vacuum
hose
and
the

vacuum
advance
is
eliminated
When
the
vacuum

cutting

valve
solenoid
is

deenergized
the

needle
valve

closes
and

the
vacuum
created

by
the
carburetor
is

introduced
into

the

vacuum
advance
unit
of
the
distributor
to

provide

usual
vacuum
advance

The

Top
switch
located

on
the
transmission
case

operates
so
as

to

interrupt
the
flow

of
electric
current

when
the

gear
is

placed
into

Top
but

allows
it

to
flow

in

other

gear
positions

Fig
ET
29

Top
switch
installation

ET
18

EMISSION
CONTROL
AND
TUNE
UP

The
thermo
switch
is
screwed
on
the

dash
side

panel

RH
The
bi
metallocated
in
the

thermo
switch

prevents

the
flow
of
electric

current
when
the

temperature
is

below

the

specifications
and

thus
ensures
a

proper
running

performance
immediately
after

starting
the

engine
in
cold

weather

A

Fig
ET
30
Thermo
switch
installation

A
view

I

llf

F

ID

1
Note
Operation
of
the
thermo
switch
is

hysteresis
of
the

bi
metal
It

opens
between
50C

410FI
and

130C

550
F
when

temperature
rises
from
low
to

high
It

closes
above
lOC

34
0
F
when

temperature
lows

from

high
to
low

An
orifice
is

employed
in
the

vacuum
hose

connecting

the
carburetor
and

tee
to
restrict
the
air
flow

by
passing

the
carburetor
when
the
needle
valve

opens
and
air
is

freely
introduced

through
the

vacuum
hose

1
Flow

guide
valve

2
Orifice

3
Vacuum

cutting

valve

solenoid

r

d

01
DATSUN

Fig
ET
31
Vacuum

tube

diagram

Checking
electrical
advance

control

system

Disengage
the

clutch
and
race
the

engine
at
normal

ambient

temperature
if
ambient

temperature
is
low

warm

up
the

engine
and

pull
off
the
vacuum
hose
from

the
distributor

Through
this

vacuum
hose

if
vacuum
is
felt
at
the

top
gear
position
and
is
not
felt
at
other

positions
it
is

satisfactory

It
is

correct
if
vacuum
is

always
felt
at
low

tempera

tures
below
l30C
550F

before
the

engine
is
warmed

up

ET
19

ENGINE

Caution

lock
the
front

and
rear
wheels

by
fully

pulling
the

parking
brake
lever
before
con

ducting
this
test

Fig
ET
32

Checking
for
operation
of
vacuum

advance

system

If

any
objection
is

found

by
the
check

mentioned

above

either
of
the

following
defects

may
be
the

cause

Poor
connection
or

broken
harness
and
fuse

2
Air

leakage
resulting
from

poor
connection
of
vacu

um
tube

3
Incorrect

operation
of

Top
switch

4
Defective

operation
of
vacuum

cutting
valve
sole

naid

5
Incorrect

operation
of
thermo
switch

Testing
of

Top
switch

1
Make
sure
of
insulation
between
lead
wire

terminal

of
transmission
switch
and
switch

body

2

Disconnect
lead
wires
at
the
switch

and
connect

ohmmeter
to
tenninals

3
Ohmmeter

should
indicate

infmity
co
when
shift

lever

is
in

Top
gear
position
And
it
should
indicate

zero
at
other

gear
position
including
Neutral

posi

tion

4
If

it
does
not

work

properly
in

step
3

replace
the

switch
with
a
new
one

Testing
of
thermo
switch

I

MaJ
e

sure
of

insulation
between
lead
wire
terminal

of
thermo
switch
and
thetmo
switch

body

2

Disconnect
lead
wire

at
switch
and
connect
ohm

meter
to
terminals
Ohmmeter
should
indicate
zero
when

temperature

indicate
the

passenger
compartment
is
above
l30C

550F

4
If
it
does

not
work

properly
in

step
3

replace

thermo
switch
with
a
new

one

AUTOMATIC

TEMPERATURE

CONTROL
AIR
CLEANER

A
T
C
AIR

CLEANER

Replacing
carburetor
air
cleaner

filter

The

paper
element

viscous

type
has
been

specially

treated
to

eliminate
bother

of

cleaning
until

replacement

It

should
be

replaced
with
a

new
one
at

regular
intervals

or
more
often

according
to
the

operating
conditions

Checking
hot
air
control
valve

Inspection

Among
the

possible
troubles
of
this
device
the

most

liable
is
the

permanent
opening
of
valve

This
trouble
is
not

noticed
in
warm
weather
but
in

cold
weather

appears
as

poor

performance
of

engine

such

as

tardy
acceleration
hesitation
or

engine
stall
In

such

case
first

inspect
this

device
before

checking
the

carburetor

Another
trouble
which

might
be

expected
is
that
the

underhood
air
is

kept
closed

by
the
valve

regardless
of

the

temperature
of
suction
air
around
the

sensor
while

the

engine
is

running
This
ttOuble

appears
in
the

form

of

extremely
excessive
fuel

consumption
or
decrease
in

power

The

inspection
of
this
device

should
be

proceeded
as

follows

Fig
ET

33
Correct

position
of
hoses

ET
20

EMISSION
CONTROL
AND

TUNE
UP

Appearance

1
First

inspect
whether
vacuum
hoses

are
connected

to
correct

positions

2

Inspect
hoses

for
cracks
distortion
or

plugging

Checking
of
vacuum
motor

I

With

engine
shut
down

inspect
the

position
of
valve

placing
a
mirror
at
the
end
of
inlet

pipe
for

inspec

tion

The
correct
condition
of
valve
is
that
it

keeps
the

inlet
of
underhood
air

open
and
that
of
hot
air

closed

Otherwise

inspect
the

linkage
of
valve

Fig
ET
34

Inspecting
valve

position

2
Disconnect
hose
at
vacuum

motor
inlet
and
direct

ly
apply
vacuum
of
manifold
to
vacuum
motor

by

connecting
another
hose

sucking
by
mouth

may
be

substituted
for
this

process
If
underhood
air
inlet
is

closed

by
valve
valve
is
in

good
condition

Inspect

linkage
if
found
otherwise
And
then
no

defect
is

found
even
in

linkage
it

signifies
the
trouble
of

vacuum
motor

Fig
ET
35

Checking
vacuum
motor

ET
21
3
The
valve

shows
correct
condition
if
it

keeps

underhood
air
inlet
closed
when
the

passage
in

the
hose

is

stopped
by
twisting
or

clamping
it
while

applying

vacuum
If
otherwise
it
is
an
indication
of

leakage

taking
place
in
the
vacuum
motor

4
When
defect
is
found

in
vacuum

motor

through
this

check
replace
the
air
cleaner

assembly

Checking
of
sensor

I
Perform
the

engine
test

by
keeping
the

temperature

around
the

sensor
below
300C
860F
Make

sure
that

the

engine
is
cooled
down

before
the
test
is
conducted

2
Before

starting
the

engine
make
certain
that
the

valve

on
underhood
air
side

fully
opens

3
Start
the

engine
and

operate
it

at
an

idling
speed

The
valve
is
in

good
condition

if
underhood
air
side

fully
closes

immediately
after

starting

4

Carefully
watch
the
valve

to
ascertain
that

it

gradually
begins
to

open
as
the

engine
warms

up
But

when
the
ambient

temperature
is
low
it
takes

con

siderable

length
of
time

for
the
valve
to

begine
to

open

or
in
some
case
it

hardly
opens
This
should

not

however
be

regarded
as
trouble

If
the
valve
does

not

operate
satisfactorily
or
if
the

condition
of
the
valve
is

questionable
further
conduct

the

following
test

5
Remove

the
air

cleaner
cover
and

put
a
thermister

or
a
small
thermometer
as
close
to
the

sensor
as

possible
with
adhesive

tape
Install
the

air
cleaner

cover

again

Fig
ET
36

Checking
sensor

1

ENGINE

6
Start
the

engine
and
continue

idling
as
described

under

paragraphs
I
2
and
3
above

When
several

minutes
have

passed
and

the
valve
is

partially
opened

read
the

thermister
indication
It
is
correct

if
the

reading
falls
between
380C
1000
F
and

550C

1300
F

If
the

reading
is
abnormal

replace
the
sensor

7

On
the

engine
equipped
with

an
idle

compensator
as

service

option
do
as
follows
before

replacing
the

sensor

Clog
hose
on
idle

compensator
side

by

twisting
or

clamping
it

and
check
the

temperature
as

given
in

paragraphs
5
and

6
above
If
the
thermometer

shO
vs

correct

temperature

replace
the
idle

compensa

tOf
if
the

reading
is
abnormal

replace
the
sensor

CRANKCASE

EMISSION
CONTROL

SYSTEM

This

system
returns
blow

by

gas
to
both
the

intake

manifold
and
carburetor

air
cleaner
The
Posirive
Crankcase
Ventilation

PCV
valve
is

provided
to
conduct
crankcase
blow

by

gas
to
the
intake

manifold

Duirng
partial
throttle

operation
of

the

enigne

the
intake

manifold

sucks
the

blow

by
gas
through
the

valve

Normally
the

capacity
of
the

valve
is
sufficient
to

handle

any
blow

by
and

a
small

amount
of

ventilating
air

The

ventilating
air

is
then

drawn
from

the
clean
side
of

the
carburetor
air

cleaner

through
the

tube

connecting

carburetor
air

cleaner
to
rocker
cover

intu
the
crankcase

Under
full

throttle
condition
the
manifold
vacuum
is

insufficient
to
draw

the
blow

by
flow

through
the
valve

and
its
flow

goes

through
the
tube

connection
in
the

reverse
direction

In
cars
with
an

excessively
high
blow

by

some
of

the
flow

will

go
through
the
tube

connection

to

the
carburetor
air

cleaner
under

all
conditions

j

Fresh
air

Blow

by

gas

1m
Air
used
in

filtering
oil
t

2

3

4
PCV
valve

Flame

arrester

Oil
filler

cap

Baffle

plate
and

steel

net

ECOOl

Fig
ET
3
7
Crankcase
emission
control

system
at

partially
throttle

open

ET
22

EMISSION
CONTROL
AND

TUNE
UP

CD

@

Fresh
air

Blow

by

gas

Air
used
in

filtering
oil
1
PCV
valve

2
Flame
arrester

3
Oil
filler

cap

4

Baffle

plate
and

steel
net

E
C002

Fig
ET
J8
Crankcase
emission
control

system
at

full
throttle

open

Checking
and

replacing
PCV
valve

Test
PCV

valve
in
accordance
with
the

following

me
thod

With

engine
running
at
idle
remove
the
ventilator
hose

from
PCV

valve
If
the
valve
is

working
a

hissing
noise

will
be

heard
as
air

passes
through
the
valve
and

a

strong

vacuum
should
be
felt

immediately
when

a

finger
is

placed

over
the
valve
inlet
If
the
valve
is

plugged
replace
with

a

new
one
Check
for

deposit
plugging
in
the
hose
Clean
if

necessary

Intake
manifold

l

illlr
nnnl

UUUU
l
I

G

EC014

FigET
39
Cross
sectional
view

of
PCV
valve
Checking
ventilation
hoses

I
Check
hoses

and
hose
connections
for
leaks

2
Disconnect

all
hoses
and
blow
them

out
with

compressed
air

If

any
hose
can
not
be
free
of

obstructions

replace

with
a

new
one

Insure

that
the
flame
arrester
is

surely
inserted
in

the

hose

between
the
air
cleaner
and
rocker

cover

EVAPORATIVE
EMISSION

CONTROL
SYSTEM

Checking
engine
compartment
hose

connections
and
fuel

vapor
control

valves

Checking
fuel
tank

vapor
liquid
separator
and

vapor

vent
line

I

Check
all
hoses
and
fuel
tank

ftIler

cap

2

Disconnect
the

vapor
vent
line

connecting
flow

guide
valve
to

vapor
liquid

separator

ET
23

ENGINE

3
Connect
a
3

way
connector
a

manometer
and
a

cock
or
an

equivalent
3

way
change
cock
to
the

end

of
the

vent
line

4

Supply
fresh
air
into
the

vapor
vent
line

through
the

cock
little

by
little

until
the

pressure
becomes
368

mm

Aq
14
5
in

Aq

5
Shut
the
cock

completely
and

leave
it
that

way

6
After
2
5
minutes
measure
the

height
of
the

liquid

in
the
manometer

7
Variation
of

height
should
remain
within
254

mmAq
1
0
in

Aq

8
When
the
filler

cap
does
not
close

completely
the

height
should

drop
to
zero
in
a

short
time

9

If
the

height
does
not

drop
to
zero
in
a

short
time

when
the

filler

cap
is
removed
it
is
the
cause
of
the

stuffy
hose

Note
In

case
the
vent
line
is

stuffy
the

breathing
in

fuel

tank
is
not

thoroughly
made
thus

causing

insufficient

delivery
of
fuel
to

engine
or

vapor

lock

It
must
therefore
be

repaired
or

replaced

3

way

connector

Cock

Air

Manometer
Vapor
liquid

seearator

Flow

guide
valve

E

CQ29

Fig
ET
40

Checking
evaporative
emission
control

system

Checking
flow

guide
valve

I
Disconnect
all
hoses
connected
to
the

flow

guide

valve

2
While
lower

pressure
air
is

pressed
into

the
flow

guide
valve
from
the
ends
of
vent
line
of

fuel
tank
side

the
air
should

go
through
the
valve
and
flow
to

crankcase

side
If
the
air
does
not
flow
the

valve
should

be

replaced
But
when
the
air
is
blown
from

crankcase

side
it
should
never
flow

to
the
other

two
vent
lines

3
While

the
air
is

pressed
into

the
flow

guide
valve
from
the
carburetor
air

cleaner
side

it
flows
to
the

fuel

tank
side
and
or

crankcase
side

4

This
valve

opens
when
the

inner

pressure
is
10

mmHg
0
4
in

Hg
In

case
of

improper

operations
or

breakage
replace
it

From

carburetor

air
cleaner

From
fuel
tank

i

I
I

ti

i

i

1
1

i
To
ran
kcase

E
C030

Fig
ET
41
Flow

guide
valve

Checking
fuel
tank

vaCCUID
relief

valve

operation

Remove
fuel
filler

cap
and
see
if
it
functions

properly

as

follows

Wipe
clean
valve

housing
and
have
it
in

your
mouth

2

Inhale
air
A

slight
resistance

accompanied
by
valve

indicates
that
valve
is
in

good
mechanical
condition
Note

also
that

by
further

inhaling
air
the
resistance
should
be

disappeared
with
valve
clicks

3

If
valve
seems
to
be

clogged
or
if
no
resistance
is
felt

replace
cap
as
an

assembled
unit

T

1i
v

rUr1f
AlI
j

r
I
r
tLMJJl

rr
L

cc

11

J
v

II

4J
L

Valve
I

valve
seat

Spring
Valve

housing

Fig
ET

42
Fuel

filler
cap

ET
24

EMISSION
CONTROL
AND
TUNE
UP

SERVICE
DATA
AND

SPECIFICATIONS

Valve

clearance

Hot
Intake

Exhaust
mm
in

rom

in

rom
in

kg
lb
0
35
0
014

0
35
0
014

10
to
15
0
394
to
0
591

10
22

Fan
belt
tension

Tightening
torque
Cold

Cylinder
head
bolts

kg
m

ft
lb

1st

turn

2nd
turn

Re

tightening
torque
Hot

Manifold
nuts

Carburetor
nuts
4
0

to
4
5

29
to
33

5
5

to
6
0
40

to
43

6
0

to
6
5
43

to
47

0
9

to
I
4

6
5
to
10

0
5

to
1
0
3

6
to
7
2

1
5

to
2
0
II
to
14

Spark
plugs

Oil

capacity
of

engine
including
oil
ftIter

Maximum
L

US

gal
Imp
gal

L

US

gal
Imp
gal
3
3

U
14

2
3

Ii
Minimum

Water

capacity
of

cooling
system

Without
heater

L
US
gal

Imp
gal

With
heater

L

US

gal
Imp
gal
4
2
1

U

4
9

I
4
11

12
5

to
14
5

I78
to
206
350

Compression
pressure
at

rpm
kg
em

psi

Battery
specific
gravity

Permissible
value
Fully
charged
value

at
200C
680F

Frigid
climates

Tropical
climates

Other

elima
tes
Over
1
22

Over
1
18

Over
1
20
1
28

1
23

1
26

Ignition
timing
degree

Distributor
50
B
T
D
C

Condenser

capacity
mm
in

degrees

IlF
Micro
Farad
0
45
to

0
55
0
018

to
0
022

49
to
55

0
22

5
Point

gap

Dwell

angle

Condenser
insulation
resistance
Mil

Mega
ohms

ET
25