sensor DATSUN B110 1973 Service Repair Manual

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

FUEl
SYSTEM

AUTOMATIC

TEMPERATURE
CONTROL

AIR

CLEANER

A
T

C
AIR
CLEANER

CONTENTS

DESCRIPTION

Air
cleaner

element

Automatic

temperature
control
air
cleaner
EF
1

EF
1

EF
2
TEMPERATURE
SENSOR

Removal

and
installation
EF
4

EF
4

DESCRIPTION

Air
cleaner
element

This
air
cleaner

element
is
of
a
viscous

paper

type
and

does
not

require
any
cleaning

regardless
of
contamination

until
it
is

replaced
with
a
new

one
Note
Never
treat

element

by
brushing
or

air

blasting

before
the
time
for

replacement

Fig
EF
l

Replacing
air
cleaner

EF

1

ENGINf

Automatic

temperature
control
air
cleaner

The
automatic

temperature
cuntrol
air
cleaner
is
of
a

special
tvpe
provided
with
a

temperature
sensor
and

vacuum
operated
valve
The
vacuum
acted

upon
the
air

2

I
control
valve
is

controlled
bv
the
sensor
See

Figure

EF

2

J

o

ECQ06

Air
inlet

pipe

2
Vacuum

motor
assembly

3
Temperature
sensor

assem
bly

4
Hot
air

pipe

5
Air
ontrol
valve

Fig
EF
2
Automatic

temperature
control

air
cleaner

If
the

temperature
of
suction
air
is
low

when
the

engine
is

running
the
air
control
valve
closes
the

underhoad
air
inlet

and
introduces
hot
air

through
the

j

I
a

0

Ej
If

f

7
@

t
t
1

Hot
air
I
cover
which
is
installed
on
the
exhaust
manifold
See

Figure
EF
3

I

@
To
manifold

EC007

J
I
Air
inlet

pipe

2
Air
control
valve

3

Diaphragm
spring

4

Diaphragm

5
Vacuum
ho

s

6
Air
bleed
valve
closed

7
Hot
air

pipe

8

Temperature
sensor

as

mbly

Fig
EF
3
Hot
air

delivery
mode

during
cold

engine
operation

EF
2

FUEL

SYSTEM

When
the

temperature
of

suction
air
around
the
sensor

reaches
430C

1l00F
and
above
the
sensor

actuates
to

open
the
air

control
valve

When
the

temperature
of

suction
air
around
the
sensor

further
rises
and

reaches
above
490C

I200F
the
air
control
valve

completely

opens
to

prevent
the

entrance
of
hot

air
and

aHows

underhood
air

alone
to
be
introduced

into
the
carburetor

See

Figure
EF4

u

C
I

1f1

lL
GJ

J
To
manifold

ECOOB

j
1
Air
inlet

pipe

2
Air
control
valve

3

Diaphragm
spring

4

Diaphragm

5
Vacuum
hoses

6
Air
bleed
valve

fully

open

7
H
t
air

pipe

8

Temperature
sensor

a5

mbly
Under
hood
air

I
I

Fig
EF
4

Underhood
air

delivery
mode

during
hot

engine
operation

The
air
control

valve
acts
in

the
manner
described

above
the

temperature
of
suction
air

around
the
sensor
is
always
kept
about
460C

I150F
See

Figure
EF
5

r
9

t
t
T
I

I

I

fY
ID

I

J
To
manifold

E
C009

I
Air
inlet

pipe

2
Air
control
valve

3

Diaphragm
spring

4

Diaphragm

5

Vacuum
hoses

6
Air

bleed
valve

partially

open

7
Hot
air

pipe

8

Temperature
sensor

assembly
Under
hood
air

J

Hot
air

Fig
EF
5

Regulating
air

delivery
mode

EF
3

ENGINE

When
the

engine
is

operating
under

heavy
load
the

air
control
valve

fully
opens
the
underhood
air

inlet
to

obtain
full

power
regardless
of
the

temperature
around

sensor

TEMPERATURE
SENSOR

Removal
and

installation

Removal

Hatten
the

tabs
of

clip
with

pliers

2
Pull
out
hoses

Note
Note
the

respective
positions
of
the
hoses
from

which

they
were
removed

3

Pry
the

tab
of

clip
with
a
screwdriver

4
Take

off
the
sensor
and

clip

I

@

f
6

7

CID

f

j
EC019

1

Pipe

2
Catch

3
Fixed
with
adhesive

4
Hose

5
Tab

6

Clip

7

Gasket
rubber

Fig
EF
6

Removing
sensor

Installation

I
Install
the

sensor
and

gasket
assembly
in
the

proper

positions

EC020

Fig
EF
7

Installing
sensor
This
control

of
carburetor
air

temperatures
allows

leaner
carburetor

calibration
with

accompanying
reduced

emissions
than

conventional
controls
and

also
eliminates

carburetor

icing

2
Insert

clip
Be

sure
to
hold
the

sensor
at
the

portion

A
in

Figure
EF
7
to
avoid

damage

Press
fit
the

clips
into
the

pipe
while

straightening
the

tabs

Note
Use

care
not
to

damage
the
sensor

EC021

Fig
EF
B

InseTting
clip

3
COIUlect
the
hoses
to
their

proper
positions

EC022

Fig
EF
9

Connecting
hoses

EF
4