check engine DATSUN B110 1973 Service Owner's Manual

EMISSION
CONTROL
AND

TUNE
UP

Capacity

Maximum
3
3
L
X

US

gal
y

Imp
gal

2
3
L
US

gal
f

Imp
gal
Minimum

Make
sure
that

engine
oil
is

not
deteriorated
with

cooling
water
or

gasoline
Drain

and
refill
the
oil

if

necessary

Notes

a
A

milky
oil
indicates
the

presence
of

cooling

water

Find
the
cause
for

necessary
corrective
action

b
Oil
with

extremely
low

viscosity
indicates

dilution
with

gasoline

2
Check

oil
level
If
found
below
L

mark
refill
to

H
mark

on

gauge

Fig
ET
3

Checking

engine
oil
level

Replacing
oil
filter

The
oil
ftIter
is
of
a

cartridge
type
The
oil
filter

can
be

removed

using
oil
ftIter
wrench
STl9320000
Check
for
oil
leaks

through
gasketed

flange
If

any

leakage
is
found

retighten
slightly
If

necessary

replace

filter
as
an

assembly

2
When

installing
an
oil
filter

tighten

by
hand

Note
Do
not

overtighten
oil
filter
or
oil

leakage
way

result

Changing
engine
coolant
L

L
C

Nissan

long
life
coolant

LLC
is
an

ethylene
glycol
base

product

containing

chemical
inhibitors
to

protect
the

cooling
system
from

rusting
and
corrosion

The
L
L
C

does
not
contain

any

glycerine
ethyl
or

methyl
alcohol
It
will
not

evaporate

or
boil

away
and

can
be
used
with
either

high
or
low

temperature
thermostat
It

flows

freely
transfers
heat

efficiently
and
will
not

clog
the

passages
in
the

cooling

system
The
LL

C
must
not
be

mixed
with
other

products
This
coolant
can
be
used

throughout
tlie

seasons
of
the

year

Whenever

any
coolant
is

changed
the

cooling
system

should
be
flushed
and

refilled
with
a
new

coolant

Check
the
level
J

Percent
Boiling
point

0
9

kgfcm2
Freeze

concen

tration
Sea
level

cooling
sys
protection

tern

pressure

30
1060

C
I

240C
15OC

221OF
255OF
5OF

50
IUY
C
1270C
35
C

2280
F
2610F
3IOF

DC
OF

0

321

10
14

20141

50
58
I

I

I

I

1

I

I

1
30
1
22

40

401

40
10
30
50
20

EGOOl

Fig
ET
4
Protection

concentration

ET
3

ENGINE

Checking

cooling
system
hoses

and
connections

Check

cooling
system
hoses

and

fiHings
for
loose

connections
and
deterioration

Retighten
or

replace
as

necessary

Inspection
of
radiator

cap

Apply
reference

pressure
0
9

kg
cm1
13

psi
to

radiator

cap
by
means
of
a

cap
tester
to

see
if
it
is
in

good
condition

Replace
cap
assembly
if

necessary

ET012

Fig
ET
5

Testing
radiator

cap

Cooling
system

pressure
test

With
radiator

cap
removed

apply
reference

pressure

1
6

kg
cm1
23

psi
to
the

cooling

system
bv
means

of
a

tester
to
check

for
leaks

at
the

system
compo

nents

Water

capacity

with
heater

4
9
l
I
Y
US

gal
l
i

Imp
gal

without
heater
4
2

l

I
i
US

gal
i

Imp
gal

Fig
ET
6

Testing
cooling
system
pressure
Checking
vaccum

fittings
hoses

and
connections

Check
vacuum

system
fittings
and
hoses
for

loose

connections
and

deterioration

Retighten
if

necessary

replace
any
deteriorated

parts

Checking

engine
compression

Compression
pressure
test

Note
To
test

cylinder

compression
remove
all

spark

plugs
and
hold
tester

fitting
tightly
in

spark
plug

hole
of

cylinder

The

tester
is
used
to

determine
whether

cylinder

can
hold

compression
or
whether
there
is

excessive

leakage

past
rings
etc

I

Td10

l
y

Fig
ET

7

Testing

compression
pressure

Test

compression
with

engine
warm
all

spark
plugs

removed
and
throttle
and
choke
valve

opened
No

cylinder

compression
should
be
less

than
80

of

highest
cylinder
s
Excessive
variation

between

cyl

inders

accompanied
by
low

speed
missing
of
the

cylinder
usually
indicates
a

valve
not

properly
seating

or
a
broken

piston
ring
Low

pressures
even

though

uniform

may
indicate
worn

rings
This

may
be

accompanied
by
excessive

oil

consumption

Test

conclusion

If
one
or
more

cylinders
read
low

inject
about
one

tablespoon
of

enigne
oil
on

top
of
the

pistons
in
low

ET
4

EMISSION
CONTROL
AND

TUNE
UP

reading
cylinders
through
spark
plug
hole

Repeat

compression
check
on
these

cylinders

1

If

compression
improves
considerably

piston
rings

are
defective

2
If

compression
does
not

improve
valves
are

sticking

or

seating
improperly

3
If
two

adjacent
cylinders
indicate
low

compression

and

injecting
oil
on

pistons
does
not
increase

compres

sion
the

cause

may
be
a

cylinder
head

gasket
leak

between
the

cylinders
Engine
oil
and
coolant

in

cylinder
could
result
from
this

problem

Compression
pressure

12
S
to
14
S

kg
cm2

178
to

206

psi
at
3S0

rpm

Checking
exhaust
manifold
heat

control

valve

Check
heat

control
valve
for

proper
operation
If
it

does
not

operate
properly
trouble
is
due
to

excess
carbon

on
shaft
or

damaged
shaft
Clean
if

necessary
The
bimetal

should
be
also
checked
for

proper
function

IGNITION

AND

FUEL
SYSTEM

Checking

battery

Check

electrolyte
level
in
each

battery
celL

L

Unscrew
each

filler

cap
and

inspect
fluid
leveL
If

fluid

level
is

low
add

distilled
water
to

bring
level

up
to

app
roximately
10
to
20

mm
0

3937
to
0
7874
in
above

plates
Do
not
overfilL

2
Measure

specific
gravity
of

battery
electrolyte
ET002

Fig
ET
B

Checking
the

specific
gravity
of

battery
electrolyte

Permissible
Full

charge
value

value

at
200C
68OF

Frigid
climates
Over
1
22
1
28

Tropical
climates
Over
1
18
1
23

Other
climates
Over
L
20
1
26

Clean
the

top
of

battery
and
terminals
with
a
solu
lion

of

baking
soda

and
water
Rinse
off
and

dry
with

compressed
air

The

top
of

battery
must
be
clean
to

prevent
current

leakage
between
terminals
and
from

positive
terminal
to

hold
down

clamp

In
addition
to
current

leakage
prolonged
accumulation

of

acid
and
dirt
on
the

top
of

battery
may
cause

blistering

of

the
material

covering
connector

straps
and
corrosion

of

straps
After

tightening
terminals
coat
them
with

petro

laturn

vaseline
to

protect
them
from
corrosion

Checking
and

adjusting
ignition

timing

I

Check

spark

plugs
and
distributor
breaker

points
for

condition

2

Thoroughly
wipe
off
dirt

and
dust
from

timing
marks

on
crank

pulley
and
front

cover

3
Warm

up
engine
sufficiently

ET
5

ENGINE

4
Install

a

timing
light
on
No

cylinder
spark

plug

wire
and
install

a
tachometer

5

Set

idling
speed
to

approximately
800

rpm

6

Check

ignition
timing
if

it
is
50BTDC
Before

Top
of

Dead
Center

by
the

use
of

timing
light

If

necessary
adjust
it

as
follows

Loosen
set
screw
to
such
an
extent
that

distributor
can

be
moved

by
hand

2

Adjust
ignition
timing
to
50BTDC

3

Lock
distributor

set
screw
and
make
sure
that

timing

is
correct

Fig
ET
9

Checking
ignition
timing

Ignition
timing
degree
50
B
T
D
C

Checking
or

replacing
distributor

breaker

point
condenser
and

spark

plugs

Distributor
breaker

point

Check
distributot
breaker

points
for
abnormal

pitting

and
wear

Replace
if

necessary
Make
sure

they
are
in

correct

alignment
for
full
contact
and
that

point
dwell

and

gap
are
correct
Clean
and

apply
distributor

grease

to
earn
and
wick

Note
Do
not

apply
grease
excessively
Distributor

Point

gap
0
45
to
0
55
mm

0
018

to
0
Q22
in

49
to
55

degrees
Dwell

angle

ET004

Fig
ET
10

Checking
distributor

point
gap

Condenser

I

Clean
outlet
of
condenser
lead

wire
and
check
for

loose

set
screw

Retighten
if

necessary

2

Check
condenser

capacity
with
a

capacity
meter

Condenser
insulation
resistance

may
be
also
checked

using
a

tester

by
adjusting
its

range
to
measure

large

resistance
value
When
condenser
is
normal
the

tester

pointer
swings
largely
and

rapidly
and
moves

gradually

back

to
the

infmite
side
When
the

pointet
does

not

stay
still
or
it

points
zero
in
resistance

replacement
is

necessary

Condenser

capacity

0

221LF
Micro
Farad

Condenser
insulation
resistance

5
Mn

Mega
ohms

Spark

plugs

Remove

and
clean

plugs
in

a
sand
blast
cleaner

Inspect

each

spark
plug
Make
sure
that

they
are
of
the

specified
heat

tange
Inspect
insulator
for
cracks
and

chips
Check

both
center
and

ground
electrodes
If

they
are

excessi
ely
worn

replace
with
new

spark

plugs
File
center
electrode
flat

Set
the

gap
to
0
8
to

0

9
rom
0

031
to
0
035
in

using
the

proper

adjusting

tool

Tighten
plugs
to

1
5
to
2
0

kg
m
11
0
to
15
0

ft

lb

torque

ET
6

ENGINE

Adjusting
carburetor
idle

rpm

mixture
ratio

Idle

mixture

adjustment

requires
the
use
of
a

CO

meter
When

preparing
to

adjust
idle

mixture
it
is

essential

to
have
the
meter

thoroughly
warmed

and

calibrated

Warm

up
the

engine

sufficiently

2
Continue

engine
operation
for
one

minute
under

idling
speed

3

Adjust
throttle

adjusting
screw
so

that

engine
speed

is
800

rpm
in
NO

position
for
automatic
transmission

4
Check

ignition
timing
if

necessary
adjust
it
to
the

specifications

Ignition
timing
SO

800

rpm

S

Adjust
idle

adjusting
screw
so
that

CO

percentage
is

1
5
t
O
S

6

Repeat
the

adjustments
as
described
in

steps
3

and

S

above
so
that

CO

percentage
is
I
i
t
O

S
at
800

rpm

Cautions

a
On
automatic
transmission

equipped

model
check
must
be
done
in
the

0

position
Be
sure
to

apply

parking
brake

and

to
lock
both
front

and
rear
wheels
with
wheel

chocks

b
Hold
brake

pedal
while

stepping
down
on

accelerator

pedal
Otherwise
car

will
rush
out

dangerously

7

On
automatic
transmission

equipped
model
make

sure
that
the

adjustment
has

been
made
with
the
selector

lever

in
N

position

And
then
check
the

specifications
with
the
lever

in

D

position
Insure
that
CO

percent
and
idle

speed
are

as

follows

Idle

rpm

CO

percentage

with
lever
in

D

position
6S0

I
S
t
O
S

If

necessary
adjust
by
progressively

turning
throttle

adjusting
screw
and
idle

adjusting
screw

until
correct

adjustments
are

made
Notes
a
Do
not

attempt
to

screw
down
the
idle

adjusting
screw

completely
to
avoid

damage
to

the

tip
which
will

tend
to
cause
malfunctions

b
After
idle

adjustment
has
been
made
shift

the

lever
to
N
or
p

position
for
automatic

transmission

c

Remove
wheel
chocks
before

starting
the

car

Throttle

adjusting

screw

Idle

adjust

ing
screw

3
Idle

limitter

cap

4

Stopper

Fig
ET
13
Throttle

adjusting
screw
and
idle

adjusting
screw

Idle
limiter

cap

Do
not

remove
this
idle

limiter

cap
unless

necessary

If
this
unit
is
removed
it
is

necessary
to
re

adjust
it

at

the

time
of

installation
To

adjust
proceed
as
follows

L
Make

sure
that

the

percentage
of
CO

contents

satisfies
the

specifications

2
Install

idle
limiter

cap
in

position
making
sure
that

the

adjusting
screw

can
further
turn
3
8

rotation
in
the

CO
RICH

direction

CARB
STOPPER

J

Z

3
8
ROTATION

0

IDLE
LIMITER
CAP

0
to
RICH

CO
LEAN

Fig
l
T
14

Setting
idle
limiter

cap

ET
8

EMISSION
CONTROL
AND

TUNE
UP

Checking
and

adjusting
dash

pot

automatic
transmission
model

only

Check

operation
of
dash

pot
It
should

not
be
cracked

or

bound
It

is
also
essential
to
check
to
be
certain

that
it

is
in

correct

adjustment

L
Check
to
be
sure
that
dash

pot
contacts

stopper
lever

when

engine
speed
reaches
1
900

to
2

000

rpm

2

Engine
should
be
slowed
down
from
3

000
to
1

000

rpm
within
a
few

seconds

Readjust
dash

pot
or

replace
it
with
a
new
one
if
it

fails

to
meet

the
above

conditions

Checking
carburetor
return

spring

Check
throttle
return

spring
for

sign
of

damage
wear

or

squareness
Discard

spring
if
found
with

any
of
above

excessively
beyond
use

Checking
choke
mechanism

choke
valve
and

linkage

1

Check
choke
valve
and

mechanism
for
free

operation

and
clean
or

replace
if

necessary

A

binding
condition

may
have

developed
from

petro

leum

gum
for
motion
on
choke
shaft
or

from

damage

2

Check
bimetal
cover

setting
position
The

index
mark

of
bimetal
cover
is

usually
aligned
at
the

middle

point
of

the
scale

Note
When
somewhat
over
choked
turn
bimetal

caver

clockwise

slightly

3
Prior
to

starting
check
to
be
sure
that

choke
valve

closes

automatically
when

pressing
down
on
accelerator

pedal

Should
it
fail
to
close

automatically
the
likelihood
is

that
fast
idle
cam
is
out
of

proper

adjustment
or

that

bimetal
is

not

properly
adjusted
calling
for

adjustment

Refer
to
Carburetor
in
Section
EF

Page
EF
15
Checking
anti

dieseling
solenoid

If

engine
will
not

stop
when

ignition
switch
is
turned

off

this
indicates

a

striking
closed
solenoid
valve

shutting
off

supply
of
fuel
to

engine
If
harness
is
in

good

condition

replace
solenoid
as
a
unit

To

replace
proceed
as
follows

Removal

and
installation

of
anti

dieseling
solenoid

Removal

Solenoid
is
cemented

at

factory
Use

special
tool

STl
91
50000
to
remove
a

solenoid

When

this
tool
is

not
effective
use
a

pair
of

pliers
to

loosen

body
out
of

position

lnstalltion

I
Before

installing
a
solenoid
it
is

essential
to
clean

all
threaded

parts
of
carburetor

and
solenoid

Supply

screws
in
holes
and
turn
them
in

two
or

three

pitches

2
First
without

disturbing
the
above

setting
coat
all

exposed
threads
with
adhensive
the

Stud
Lock
of

LOCTlTE
or

equivalent

Then

torque
screws
to
35
to
55

kg
cm
30

to
48
in

lb

using
a

special
tool
STl9150000

After

installing
anti

dieseling
solenoid
leave
the
carbu

retor
more
than
12

hours
without

operation

3

After

replacement
is
over
start

engine
and
check

to
be
sure
that
fuel
is
not

leaking
and
that
anti

dieseling
solenoid
is
in

good
condition

Notes
a
Do
not
allow
adhesive

getting
on
valve

Failure
to
follow
this
caution
would
result
in

improper
valve

performance
or
clogged
fuel

passage

b
I
n

installing
valve
use
caution
not
to
hold

body
directly
Instead

use

special
tool

tighten

ing
nuts
as

required

ET
9

ENGINE

Replacing
fuel
filter

Check
for
a

contamination
element
water
deposit
and

defection

Fig
ET
15
Fuel
strcrineT

All

engines
use
a

cartridge
type
strainer
If
it
is
found

to
be

defective

replace
as
an

assembly

Checking
fuel
lines

hoses

pipings
connections
etc

Check
fuel
lines
for
loose
connections
cracks
and

deterioration

Retighten
loose
connections
if

necessary

replace
any

damaged
or

defective

parts

THROTTLE
OPENER
CONTROL

SYSTEM

The
function
of
the
throttle

opener
is

to

open
the

throttle
valve
of
carburetor

slightly
in

vehicle
decelera

tion

During
deceleration
manifold
vacuum
rises

and
a

quantity
of
mixture
in
the

enigne
is

not
sufficient
so
that

a
normal
combustion
can
not
continue
and
a

great

amount
of
unburned
HC
is

emitted
The
carburetor

equipped
with
the
throttle

opener
supplies
the

engine

with
an

adequate
charge
of
combustible
mixture
to

keep
proper
combustion

during
deceleration

resulting
in
re

markable
reduction
of

He
emission

The

operation
of
the

throttle

opener
is
as
follows
A

schematic

drawing
of
the

system
is
shown
in

Figure

ET
16

At
the

moment
when
the
manifold

vacuum
increases

as

occurs

upon
deceleration
the

control
valve

opens
to

transfer
the
manifold

vacuum
to

the
servo

diaphragm

chamber
and
the
throttle
valve
of
the
carburetor

opens

slightly
As
the
vehicle

speed
decreases

above
16

km
h

10

MPH
for
manual
transmission

only
the
manifold

vacuum
lowers
to
the

predetermined
value
The
vacuum

control
valve

begins
to
close

gradually
keeping
the

manifold

vacuum
at
the

predetermined
constant
value

As
a

result
both
low
HC
emission
and
normal

engine

brake

during
deceleration
are

obtained

The

altitude
corrector
is

provided
with
a

slight
preload

to

compensate
the

variation
of
the

atmospheric
pressure

Vacuum

control
solenoid

The

purpose
of
this
control
is
to
return
the

speed
of

engine
to
the

prescribed
idling
positively
To
be

accurate
the

control

prevents
the
throttle

opener
from

taking
normal

operation
when
vehicle

speed
is
below

16

km
h

IO
MPH
for
manual
transmission

equipped

model
or
when
transmission
is

placed
in

N
or

P

position
for
automatic
transmission

equipped
model

Current
flows

through
the

solenoid
when
vehicle

speed

falls
below
16
km
h
10

MPH
on

manual
transmission

equipped
model
or
when
the
transmission
is

placed
in

N
or

P

position
on
automatic
transmission

equipped
model

As
this
takes

place
the
needle
valve
is
lifted
off
its
seat

directing
air
from
the
air
chamber
to
the
servo

diaphragm
This
releases
the

operation
of
the
throttle

opener

When

vehicle

speed
goes
over
16
km
h

IO
MPH
or

when
transmission

is

placed
in
a

position
other
than

N

or
P

position
the
solenoid
is

deenergized

allowing
the
throttle

opener
to
take
normal
action

to

reduce
He
emission
to
a
minimum

ET
10

EMISSION
CONTROL
AND

TUNE
UP

Operation
manual
transmission

equipped
model

The

operation
of
the
solenoid
is

by
means
of
the

movement
of

the

speedometer
needle

When
vehicle

speed
falls
below
16

km
h

10

MPH
the

needle
movement

produces
a

signal
which
in
turn
is

amplified
to
actuate
the

solenoid

I
Vehicle

speed
Speed
Throttle

Throttle

switch
opener

opener

solenoid

Below
16
km
h
Not

10
MPH
ON
ON

actuated

Above

16
km
h

OFF
OFF

Actuated

10
MPH

Operation
automatic
transmission

equipped
model

The

solenoid
is

operated
by
an
inhibitor

switch
which

actuates
the
solenoid

only
when
the
transmission
is

placed
in

the
N
or
P

position

c
fil

rn

AT057

Fig
ET
18

Inhibitor
switch
installation

Checking
and

adjusting
throttle

opener

Principally
it
is

unnecessary
to

adjust
the
throttle

opener
however
if
there
is

any
requirement
the

adjust

ment

procedure
is
as

follows

Prepare
the

following
tools

1
A

tachometer
to
measure
the

engine

speed
and
a

screwdriver

2
A
vacuum

gauge
and

connecting
hose

ET
13
Notes
a
A

quick

response
boost

gauge
such

as
Bour

don
s
tube

type
is
recommended
Do
not

use

mercury
manometer

b

Any
special
tools

are
not

required

Warming

up

Warm

up
engine
until
it
is
heated

to

operating

temperature
Make
sure
that

the
automatic
choke
valve

is

fully
open

Connecting
vacuum

gauge

Disconnect
vacuum
hose
between
intake

manifold
and

automatic

temperature
controlled
air

cleaner
install

a

vacuum

gauge
to
intake
manifold
connector
as
shown

in

Figure
ET

19

1
Intake
manifold

2
Connector

3
Vacuum

gauge
4
Vacuum
control
valve

5
Throttle

opener

solenoid

Fig
ET
19

Adjusting
throttle

opener

Deenergizing
solenoid

Disconnect
throttle

opener
and
vacuum

cutting
valve

solenoid
harness

and
free
solenoid

Adjusting
idling

Check
the

engine
idling
Adjust
if

necessary

Engine
idling

rpm
Idling

timing

I
CO

degree

SO

BTDC

I
L51c0
5

SO

BTDC

I
I
S
1c
0
5
M
T
Car

A
TCar
800

6S0
in
D

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