key DATSUN PICK-UP 1977 Service Manual

Fresh
air

Blow

by
gas

CHECKING

VENTILATION

HOSE

1

Check
hoses
and
hose
connec

tions
for
leaks

2
Disconnect
all
hoses
and
blow

them
out
with

compressed
air

If

any
hose

cannot
be
free
of

obstructions

replace

Ensure
that
flame

arrester
is

surely

inserted
in
the

hose
between
air

cleaner
and
rocker
cover

CHECKING
EXHAUST

MANIFOLD
HEAT

CONTROL
VALVE

Run

engine
and

visually
check

counterweight
to
see

if
it

operates

properly

I
For

some
time

after

starting

engine
in
cold

weather

counterweight

turns

counterclockwise
until

it
comes

into

contact
with

stopper

pin
installed

to

exhaust
manifold

Counterweight

gradually
moves

down

clockwise

as

engine
warms

up

and
ambient

temperature
goes
higher

around
exhaust
manifold

2

When

engine
speed
is

increased

discharge
pressure
of
exhaust

gases

causes

counterweight
to
move
down

ward

clockwise
Engine
Tune

up

CoOl
1

Oil
level

gauge

2

8affle

pia
te

3

Flame
arrester

4

Filter

5
P
C
V
valve

6

Steel
net

7

Baffle

plate

1fiI

o

EC716

Fig
ET
20
Crankcaae
emi
ion

control8
tem

3
When
heat

control
valve
is
in
the

full

open

position
counterweight

moves
further

clockwise

exceeding
the

position
described

in
1

1
above
and

stops

again
coming
into

contact
with

stopper

pin

ct

t

C

EC245

1

Counterwe
ht

2

Stopper
pin

3

Heat
control

valve

Fig
ET
21
Cold

operation
of
counte

weigh
t

EC246

1

Counterweight

2

Stopper
pin

3
Heat
control
valve

Fig
ET

22
Hot

operation
of
counter

weight

ET

14
2
With

engine

stopped
visually

check

E
F
E

system
for
the

following

items

I
Thermostat

spring
for
dismount

ing

2

Stopper

pin
for

bend
and
count

er

weight
stop
position
for

dislocation

3

Check
heat
control

valve
for

malfunction

due
to
break
of

key
that

locates

counterweight
to
valve

shaft

4

Check
axial
clearance

between

heat
control

valve
and
exhaust
mani

fold
Correct
clearance
is
0
7
to
1
5

mm
0
028
to

0
059
in

5

Check
welded

portion
of

heat

control

valve
and

valve
shaft
for

any

indication
of
crack

or

flaking

6
Rotate
heat

control
valve

shaft

with
a

fmger
and

check
for

binding

between

shaft
and

bushing
in

closing

and

opening
operation
of
heat
control

valve
If

any
binding
is
felt
in

rotating

operation
move
valve
shaft
in

the

rotation
direction
several
times
If

this

operation
does
not

correct

binding

condition
it
is
due

to
seizure
between

shaft
and

bushing
and

exhaust
mani

fold

should
be

replaced
as
an
assem

bly

CHECKING
SPARK

TIMING
CONTROL

SYSTEM

This

system
is

installed
on
non

California
automatic
transmission

models

SPARK
DELAY
VALVE

Automatic
transmission

models

only

This
valve

delays
vacuum

spark

advance

during
rapid
acceleration
it

also
cuts

off
the

vacuwn

spark
advance

imme

iately
upon
deceleration

The

valve
is

designed
for
one

way
opera

tion

and
consists

of
a
one

way
umbrel

la
valve
and
sintered
steel
fluidic

restrictor

OPERATI
NG

PRESSURE
OF

BOOST
CONTROLLED

DECELERATION

DEVICE
B
C
D
D

ADJUSTMENT

CHECKING
a
C
D
D
CIRCUIT

WITH
FUNCTION
TEST

CONNECTOR

Manual
transmission
models

I

Check
for

continuity
between

@

and@
at
a

speed
of
zero
km
Refer

to

Figure
ET
30

B
C
D

D
circuit
is

functioning

properly
if

continuity
exists
and
volt

meter

reading
is
0
volt
d
c
in

step
2

below

If

continuity
does
not
exist
check

for
disconnected
connector
and
or

faulty

amplifier
speed
detecting

switch
or
B
C

D
D
solenoid
valve

2
Check
for

presence
of

voltage

across

@
and

@
at
a

speed
of
more

than
16
km
h

10
MPH
Refer
to

Figure
ET
31

Conduct

this
test

by
one
of

the

following
two

methods

i
Raising

up
rear
axle

housing
with

stand

2
Chassis

dynamometer
test

If
voltmeter

reading
is

0
volt
at

a

speed
of

more
than
16

km
h
10

MPH
circuit
is

functioning
prop

erly

If
voltmeter

reading
is

not
0
volt

check
for
disconnected
connector

burned
fuse

faulty

amplifier

B
C
D
D

solenoid
valve
or

speed

detecting
switch

3

If

by
above
checks

faulty
part
or

unit
is
located
it

should
be
removed

and
tested

again
If

necessary
replace

Automatic
transmission

models

I

With
inhibitor

switch
ON
UN

or
P

position
check
for

presence
of

voltage
across

@
and

@
Refer
to

Figure
ET
30

If

voltmeter

reading
is

12
volts

d
c

B
C
D
D

circuit
is

func

tioning
properly
Engine
Tune

up

If
voltmeter

reading
is

zero
check

for
disconnected

connector

faulty

solenoid
valve
or
inhibitor
switch
erly

If
ohmmeter

reading
is

32
ohms
or

above
check
for

poor
connection

of

connector

faulty
B

C
D
D

sole

noid
valve

or
inhibitor

relay

3

If

by
above
checks

faulty
part
or

unit
is

located
it
should
be
removed

and
tested

again
If

necessary
replace
2

With
inhibitor

switch
OFF

41
2
D
or
R

position

check
for
resistance

between

@
and

@
Refer

to

Figure
ET
31

If

ohmmeter

reading
is
25
ohms
or

below
circuit
is

functioning
prop

l

E
r
1

Ignition

key

2

Fuse

3

Amplifier

4

Speed
detecting
switch

Above
10

mph
OFF

Below

10

mph
ON

5

Function
test
connector

6
B
C
D
D

solenoid
valve

EF711

Fig
ET

30
B
C
D
D
circuit
with

function
tedconnectoT

Manual
transmission
modela

@

1

Ignition

key

2

Inhibitor
switch

N
P

positions
ON

I
2

D
R

positions
OFF

3
D
C
D
D
solenoid
valve

4

Function
test
connector

5
Inhibitor

relay

EF712

Fig
ET
31

Checking
B
C
D
D
circuit
with
function
tf
st
connf
ctor

Automatic
transmiMion
modtla

ET
17

r

CHECKING
B
C

D
D

SOLENOID
VALVE

I
Turn
on

engine
key
Do
not
start

engine

2
Ensure
that
solenoid
valve

clicks

when

intermittently
electrified
as

shown
in

Figure
ET
37

Fig
ET

37

Checking
solenoid
uolV
l

I

l

EF264

2

Turn

ignition
key
to
ON

posi

tion

3

Ensure
that
tester

pointer
deflects

when

ignition
key
is

turned
on

4

If

tester

panter
does
not
deflect

when

solenoid
valve

and

speed
detect

ing
switch

circuits

are

functioning

properly
amplifier
is

faulty
Engine
Tune

up

3
If
a

click
is

heard
solenoid
valve

is
normal

4

If
a
click
is
not
heard

at
all
check

for

continuity
with
a
circuit

tester
If

discontinuity
is

detected

replace
sole

naid
valve

CHECKING

AMPLIFIER

Manual
transmission

models

The

amplifier
is

installed
at
the

rear

of
the

speedometer
To

check

proceed

as
follows

1
Set
circuit

tester
in

d
c

ampere

range
IA

min
full
scale

connect
test

probes
of
tester
as

shown
in

Figure

ET
38

Do

not
confuse

positive
line

with

negative
line

M

p
1

II

L
o

A

I
of

j
t
J

f

T

1

Ignition
key

2

Amplifier

3

Speed

detecting
switch

4
B

C
D

D

solenoid
valve

Fig
ET
38

Checking

amplifiu

REPLACING
AIR

PUMP
AIR
CLEANER

ELEMENT

Remove
air

hose
then
detach
air

cleaner
from

hoodledge
Air
cleaner

element

and
air

cleaner
lower

body
are

built
into

a
unit
construction

Replace

air

cleaner
element
and
lower

body
as

an

assembly

ET

20
EC323

Fig
ET
39

Repl4cing
air
cleaner

element

CHECKING

EXHAUST

GAS

RECIRCULATION

E
G

R

CONTROL

SYSTEM

Checkln

E
G
R
control

system
In
Ita

mounted

condition

I

M
ake
a

thorough
visual
check
of

E

G
R
control

system
If

necessary

wipe
away
oil
to

facilitate

inspection

If

hoses
are

cracked
or

broken
fe

place

2
With

engine
running
check

E
G
R

warning
system
for

proper

function
Make
sure
that
E

G
R
warn

ing
lamp
light
when

ignition
switch
is

turned
to
START

position
starter
mo

tor
runs
If
E
G
R

warning
lamp
does

not

light
inspect
harnesses
and
con

nectors
or

replace
warning
lamp
Then

turn

ignition
switch
to

ON

position

and
check
the

following
items

I

If
odometer
of
detector
drive

counter
has
not
reached
50

000

counts
make
sure
that
E

G
R

warning

lamp
does
not

light

2

If
odometer
of
detector
drive

counter
has
attained
50

000
counts

make

sure
that
E

G
R

warning

lamp

lights

If

warning

lamp
does
not

light

check
harnesses

connector
and
de

tector
drive
counter

replace

warning

lamp
or
detector
drive

counter
if

necessary

Note

Operation
of
E

G
R

warning

lamp
is

as
follows

2
Turn
crankshaft
until
No
I

pis

ton
is
at
T
D
C

on
its

compression

stroke

3
Make

sure
thai
camshaft
sprock

et
location
notch
and

plate
oblong

groove
are

aligned
at
their
correct

positions

4

When

installing
cylinder
head

make
sure

that
all
valves
are

apart

from
heads
of

pistons

5
Do

not
rotate
crankshaft
and

camshaft

separately
or
valves
will
hit

heads
of

pistons

6

Temporarily
tighten
two
bolts

CD

V
sJiown

in
Fig

re
EM
96

Tightening
torque

2

kg
m

14
ft
b

15
Install
crankshaft

sprocket
and

oil

pump
drive

gear
and
fit
oil

thrower

Note
Make
sure
lhat

maling
marks
of

crankshaft

sprocket
face
10
Cront

16
Install

timing
chain

Noles

a
Make

sure
that
crankshaft
and
cam

shaft

keys
point

upwards

Fuel

pump
drive

earn

2
Chain

guide

3

Chain
tensioner

4

Crank

sprocket

5
earn

sprocket

6
Chai

guide

EM439

b
Set

timing
chain

by

OOgning
its

mating
marks
with
those
oC
crank

shaft

sprocket
and
camshaft

sprock

et
at
the

right
hand
side
There
are

forty
four
chain
links
between
two

mating
marks
of

timing
chain

c
NO
2
hole
is

Cactory

adjusted

When
chain
stretches

excessively

adjust
camshaft

sprocket
at

No
3

hole

d
Use
a

set
of

timing
marks
and

location
hole

numbers
Engine
Mechanical

17
Install
chain
slack
side

guide
to

cylinder
block

18
Install
chain
tensioner

Note

Adjust
protrusion
oC
chain
ten

sioner

spindle
to
0
mm
0
in

Fig
EM
98

lmtalling
chain
tensioner

19
Press
new
oil
seal
in

front
cover

Notes

a
Front

cover
oil
seal
should
be
reo

placed
when
Cront
cover
is

disas

sembled

b
BeCore

pressing
oil
seal
into
Cront

cover

give
coating
of

engine
oil
to

periphery
of
oil
seal

c
This
oil
seal
is
a
threaded
seal

type

which
has

improved
sealing
charac

teristics
Do
not

apply
grease
to

sealing

lip

20
Install
front
cover
with

gasket
in

place

1

Timing
mark

2

Timing
mark

EM545

Fig
EM

99

Installing
fronl
COlHlr

Notes

a

Apply
sealant
to
Cront
cover
and

corners
oC

upper
section
of

cylinder

block

as
shown

in

Figure
EM
78

EM
24
b
Install
Cront
cover
with
head

gasket

in

place

c

Check

height
diCCerence
between

cylinder
block

upper
Cace
and
Cront

cover

upper
Cace
DifCerence
must

be
less
than
0
15

mm
0
0059
in

d

Note
that
difCerent

types
oC
bolts

are
used

e

Before

installing
front
cover
on

cylinder
block

apply

coating
oC

engine
oil
10

sealing
lip
of
oil

seal

EMS11

Fig
EM
lOD
Front

cover
bolts

Tightening
torque

Size
M8
0
315
in

1
0
to
1
3

kg
m
7

2
to
9
4

ft
lb

Size
M6
0
236
in

0
4
to
0
6

kg
m
2

9
to
4

3
ft
lb

21
Install
crankshaft

pulley
and

water

pump
assembly
then
set
No
I

piston
at
ToO
C
on
its

compression

stloke

Crankshaft

pulley
nu
I

tightening
torque

12
to
16

kg
m
B7
to
116
ft

lb

EM546

Fig
EM
Ol

lnstallingcran
haft

pulley
and

water

pump

22

Finally

tighten
head

bolts
to

the

specified
torque
in

three

steps

according
to
the

lightening
sequence

shown
in

Figure
EM
96

Note
thai
Iwo

types
of
bolts

are

used

ELECTRIC
AUTOMATIC

CHOKE

Checklna
automatic
choke

heater
circuit
with
function

test
connector

Caution
Do
not
altach
test

leads
of

a

circuit
tester
to
those
other
than

designated
Refer
to

figure
Ef
43

I

With

engine
not
running
check

for

continuity
between
A

and
B

as

shown
in

figure
Ef
43

If

continuity
exists
heater
is
func

tioning
properly

If

continuity
d
s

not
exist
check

for
disconnected
connector

or

open

P
T

e
heater
circuit

2

With

engine
running
at
idle
check

for

presence
of

voltage
across
A
and
B

as
shown
in

figure
EF
43

If

voltmeter

reading
is
12
volts

d
c

heater
circuit
is

functioning

properly

If

vohmeter
reading
is
zero
check

for
disconnected
connector
open

circuit
or

faulty
automatic
choke

relay

3

Replace
faulty
parts

J
j

N

j

EF710
1

ignition
key

2
Automatic
choke

relay

Engine
stop
OFF

Engine
start
ON

3
Automatic

choke
heateI

4

Function
test
connector

5
Altema
tor

Fig
EF
43
Checking
oulomalic

choke
heater
circuit
with

fu
nc
non
led

connector
Engine
Fuel

Automatic
choke

I
Before

starting
engine
fully
de

press
al
celerator

pedaJ
to
ensure
that

choke
valve

doses

properly

Push

choke
valve
with
a

finger

and
heck
for

binding

3
Check
0
be
sure
that
bi

rnetal

cover
index

mark
is
set
at
the
cen
leT
of

choke

housing
index
mark
a
s
shown
in

Figure
EF
44

Note
Do
not
set
b
metal
cover
index

mark
at

any
position
except
the

center
of
choke

housing
index

marl

tE

jL

J

Thermostat
cover

Bi
metal

chamber

2
Thermostat

housing

3
Groove
ET034

Fig
EF

44
Bi

metol
tting

4

Check
automatic
choke
heater

source

wiring
for

proper
connection

then
start

engine

5

After

warming
up
the

engine
see

that

choke
valve
is

fully

open

6
If
automatic
choke
heater

source

wiring
is

normal
and
choke

valve
does

not

operate
after
warm

up
replace

hi

metal
co
t
er

Automatic

choke

relay

I
Remove
automatic
choke

relay

Auto
choke
heater

relay

EF278

Fig
EF
45
Location

of
automatic

choke

relay

EF
24
2

Make
an

operational
check
of

automatic
choke

relay
as
shown
in

Figure
EF
46

Apply
2

volts
d
c
across
termi

nals
I
and
3
to
ensure
that

i

ontinuity
exists
between
terminals

2
and
4

Check
t
lal

continuity
does
not

exist
between
terminals

2
and
4

when
no

voltage
is

applied
across

them
If
results
satisfies
the
above

automatic
choke

relay
is

functioning

properly
if
not

replace
choke

relay

1
2

3

y
4

EF723

Fig
EF
46

Checking
automatic
choke

relay

Automatic
choke
heater

I
Measure
resistance
of
choke

heater

as
shown
in

figure
EF
47

spe
ified
re
s

an
ce
is
3
7
to
8
9

ohms

F

EF261

Fig
EF
47
Automatic
choke
heater

check

2
If
measured
value
is

not
within

the

specification
replace
bi
metal

cover

INTERLOCK
OPENING
OF

PRIMARY
AND
SECONDARY

THROTnE
VALVE

Figure
EF
48
shows

primary
throt

tie
valve

opened
SO
When

primary

throtlle
valve
is

opened
50
the

adjust

plate
integrated
with
throttle
valve
is

in
contact
with
return

plate
at
A

AUtomatic

trailamlsalon
modela

I

With
inhibitor

switch
ON
UN

or
P

position
check
for

presence
of

voltage
across
A
and
B
Refer
to

Figure
EF
51

If
voltmeter

ading
is

12
volts

d
c
B
C
D
O
circuit
is

func

tioning
properly

If
vol
tmeter

ading
is

zero
check

for
disconnected

connector

faulty

solenoid
valve

m
inhibitor

switch

2
With
inhibitor

switch
OFF

HI
2
IY
or
oR

position
Engine
Fuel

check

for
resistance

between
A
and
B

Refer

to

Figure
EF
51

If

ohmmeter

reading
is
25

ohms
or

below
circuit
is

functioning
prop

erly

If

ohmmeter

reading
is
32

ohms
or

above

check
for

poor
connection

of
connec
or

faulty
B
C
D
D
sole

noid
valve
or
inhibitor

relay

3

If

by
above
checks

faulty
part
or

unit
is

located
it

should
be
moved

and

tested

again
If

necessary
replace

yu
@

@
1

Ignition
key

2

Inhibit
T
switch

N
P

positions
ON

I

2
D
R

positions
OFF

3
D

C
D

D
solenoid
valve

4

Function
test
connector

5

Inhibitor

relay

EF712

Fig
EF
51

Checking
B
C

D
D
circuit
with

unction
t
st
connector

for
automatic
transmi
sion

Set

pressure

of

Boost
Controlled

Deceleration
Device
B
C
D
O

Generally
it
is

unnecessary
to
ad

just
the

B
CD
D

however
if

it
should

become

necessary
to

adjust
it
the

procedure
is
3S
follows

Prepare
the

foUowing
tool

I

Tachometer
to

measure
the
en

gine
speed
while

idling
and
a

screw

driver

2
A

vacuum

gauge
and

connecting

pipe

Note
A

quick
response

type
hoost

gauge
such
as
Bourdon
s

type
is

recommended
a

mercury
type

manometer

should
not
be
used

To

properly
set
the

B
C
D

D
set

pressure
proceed
as
follows

I
Remove

the
harness
of
solenoid

valve
To
B
D
D

solenoid
valve

1

B
C
D
D

olenoid

valve

harness

EF262

Fig
EF
52

Removing
harness

of

solenoid
valve

2

Connect
rubber
hose
between

vacuum

gauge
and
intake
manifold

as

shown

Fig
EF
53

Connecting
vacuum

gauge

EF
26
3

Warm

up
the

engine
until
it
is

heated
to

operating
temperature

Then

adjust
the

engine
at
nunnal

idling
setting
Refer
to
the

item

Idling

Adjustmenl
in

page
EF

21

Idling

engine
speed

Manual
transmission

750

rpm

Automatic
transmission

in
D

position

650

rpm

4

Run
the

engine
under
no

load

Increase

engine
speed
to
3
000
to

3
500

rpm
then

quickly
close
throttle

valve

5
At
the
time
the
manifold
vacuum

p
ssure
increases

abruptly
to

600

mmHg
23

62

inHg
or
above

and

then

graduaUy
decreases
to
the
level

set
at

idling

6
Check
that
the
B
C
D
D
set

pres

sure
is
within
the

specified
pressure

Specified

pressure
0
m
sea
level

and

760

mmHg
30

inHg
atmos

pheric

pressu

Manual
transmission

510

to
550

mmHg

20
1

to

21
7

inHg

Automatic
transmission

490
to

530

mmHg

19Tto
20

9

inHg

Notes

a
When

atmospheric
pressure
is

known

operating
pressure
will

be

found

by
tracing
the

arrow
line

A

See

Figure
EF
56

When
alti

tude
is
known

operating
pressure

will

be
found

by
tracing
the
arrow

line
B

See

Figu
EF
56

b

When

checking
the
set

pressu
of

B

CD
D
find
the

specified
set

pressu
in

Figure
EF

56
from
the

atmospheric
pressure
and
altitude

of

the

given
location

For

example
if

an
automatic
trans

mission
model
vehicle

is
located
at

an
altitude
of
1

000

m
3

280
ft

the

specified
set

p
ssu

for

B
C
D
D
is
445

mmHg
17

5

inHg

7
If
it
is

higher
than

the
set
level

turn
the

adjusting
screw
or
nut
until

correct

adjustment
is

made

300
n

o

o

B
C

D
D
solenoid

valve

I
Turn
on

engine
key
Do
not
start

engine

Ensure
that
solenoid
valve

clicks

when

intermittently
electrified
as

shown
in

Figure
EF
57
1

000
2
000
3

000
4
000
5
000

0
5
1

0
6
000
ft

Altitude

km

1
5
2

0

EF558

Fig
EF
56

Changes
in
set

pres
ure
versus

changes
in

atmospheric

pressure
and
altitude

EF262

Fig
EF
57

Checking
solenoid
valve

EF

28
3

If
a

dick
is
heard
solenoid
valve

is

normal

4
I
f

a
dick
is
not
heard
ar
all
check

for
continuity
with

a
circuit
tester

If

discontinuity
is
detected

replace
sole

noid
valve

Amplifier
Manual

transmIssIon

models

The

amplifier
is
installed
at

the
rear

of
the

speedometer
To
check

proceed

as
follows

I

Set
circuit
tester
in
d
c

ampere

range
IA
min

fuU
scale
connect
test

probes
of
tester

as
shown
in

Figure

EF
58

Do
not
confuse

positive
line
with

negative
line

2
Turn

ignition
key
to

ON

posi

tion

I

t

EF264

1

Ignition
key

2

Amplifier

3

Speed
detecting
switch

4
B
C
D
D
solenoid
valve

Inhibitor

switch

Automatic

transmission

models

Refer
to
the
AT
section

Inhibitor

relay

Automatic
transmission

models

Inhibitor

relay

EF724

Fig
EF
59
Location
of
inhibitor

relay

2
Make

an
inhibitor

relay
check
as

shown
in

Figure
EF
60

Apply
12
volts
d
c
across
termi

nals
1

and
4

to
ensure
that

continuity

exists
between
terminals
2
and
3

Check
that

continuity
does
not

exist
between
terminals
2
and
3
when

no
voltage
is

applied
across
them
Engine
Fuel

3

Ensure
that
tester

pointer
deflects

when

ignition
key
is
turned
on

4
If
tester

pointer
does
not

deflect

when
solenoid
valve
and

speed
detect

ing
switch
circuits
are

functioning

properly
amplifier
is

faulty

Fig
EF
58

Checking
amplifier

If
results
satisfy
the
above

inhi

bitor

relay
is

functioning

properly
if

not

replace
inhibitor

relay

it
@

j
l

j
4

L
I

44
11

oJ

EF287

Fig
EF

60
Checking
inhibitor

relay

ALTITUDE

COMPENSATOR

California
models

Make
sure

that
altitude
com

pensator
to
carburetor

hoses
are
con

nected

properly
and
that

they
are
not

cracked
and
obstructed

2
Check
that
altitude

compensator

is

properly
set

At
low
altitudes

At

high
altitudes

Notes

a
The
idle

Pm
and
CO

vary
accord

ing
to
the
altitude
Therefore

they

should
be

properly
adjusted
when

the

position
of
the
H
L
lever
is

changed
Close

Open

EF
29
b
Counties
1

219
m
4
000

ft
or

more
above
sea
level
have
been

designated
by
law
as

High
Altitude

Counties
For
further
details
refer

to

1977
DATSUN
PICK
UP
Service

BuUetin
Pub
No
257

Q0

1
v

EF733

Fig
EF
61

Checking
altitude

compensator

MAJOR
SERVICE

OPERATION

The

perfectly
adjusted
carburetor

delivers
the

proper
fuel

and
air
ratios

at
all

speeds
for
the

particular
engine

for
which
it

was

designed
By
com

pletely
disassembling
which
will
allow

deaning
of
all

parts
and

passages
the

carburetor
can
be

maintained
its

origi

nal
condition
and
will
continue

to

deliver
the

proper
ratios

To
maintain

accurate
carburetion

of

passages
and

discharge
holes

ex

treme
care
must
be
taken
in

cleaning

Use

only
carburetor
solvent
and

compressed
air

to
clean
all

passages

and

discharge
holes
Never
use
wire
or

other

pointed
instrument

to
clean
or

carburetor
calibration
will
be
affected

REMOVAL

Remove
carburetor
from

engine

taking
sufficient
care
to

the

following

Precautions

a
When

disconnecting
fuel
lines
do

not

spill
fuel
from
fuel

pipe

b
When

removing
carburetor
do
not

drop
any
nut

or
bolt
into
intake

manifold

c
Be
careful
not
to
bend
or
scratch

any
part

Emission
Control

System

EARLY

FUEL

EVAPORATIVE

SYSTEM
E

F
E

DESCRIPTION
spring
and

counterweight
which
are

assembled
on
the

valve
shaft

projecting

to
the

rear
outside
of
the
exhaust

manifold
The

counterweight
is
se

cured
to
the
valve
shaft
with

key
bolt

and

snap
ring
EC
4
A

control
valve
welded
to

the

valve
shaft
is

wtalled
on
the

exhaust

manifold

through

bushing
This
con

trol

valve
is

called
Heat

control

valve
The
heat
control

valve
is

ac

luated

by
the

coil

spring
thermostat
Construction
of
the

early
fuel

evap

orative

system
is

shown
in

Figure

r
I

1

@

rW

9

Sc
w

10
Thennostat

spring

11

Coil
spriiig

12
Control
valve
shaft

13
Heat
control

valve

14

Bushing

15

Cap

16
Exhaust
manifold
1
Intake
manifold

2
Stove

gasket

ManifoktstOve

4
Heat
shield

plate

5

Snap
ring

6

Counterweight

7

Key

g

Stoppel
pin

EC532

Fig
EC
4
Early
Fuel

Evaporutive
tem
E
F
E

The

early
fuel

evaporative
system
is

provided
with
a
chamber
above

a

manifold
stove
moonted
between
the

intake
and
exhaust

manifolds

During

engine

warming
up
air
fuel
mixture
in

the

carburetor
is

heated
in
the
cham

bet

by
exhaust

gases
This
results
in

improved
evaporation
of

atomized
fuel

droplets
in
the
mixture
and
in

smaller

content
of

hydrocarbons
He
in
the

exhaust

gas
especially
in

cold
weather

operation

The
exhaust

gas
flow
from
the

engine
is

obstructed

by
the
heat
con

trol

valve
in
the

exhaust
manifold
and
is

changed
in

direction
as
shown

by

the
solid

lines
in

Figure
EC
4
The

exhaust

gas
heats
the
manifold
stove

Open
close

operation
of
the

heat

control
valve
is
controlled

by
the

counterweight
and
thermostat

spring

which
is
sensitive
to
the

ambient
tem

perature
around
the

exhaust
manifold
With
this
condition
the

heat
control

valve
is
in

the

fully
closed

position

obstructing
the
flow
of

exhaust

gas
As

engine
tempera
lure

goes
up
and

the

ambient

temperature
becomes

high

enough
to
actuate
the
thermostat

spring
the

counterweight
begins
to

rotate
clockwise
and

again
comes
into

con

tact
with

the

stopper
pin
With
this

condition
the

heat
control
valve
is
in

the
full

open
position
and
exhaust

gas

passes
through
the
exhaust
manifold
as

shown

by
the
dotted

lines
in

Figure

EC
4
without
heati

ng
the
manifold

stove
OPERATION

The

counterweight
rotates
counter

clockwise
and

stops
at

the

stopper
pin

mounted
on
the
exhaust

manifold

while

the

engine
temperature
is
low

EC
6

REMOVAL
AND
INSTAUATION
Emission
Control

System

EC533

Remove

snap
ring
D
and
lock
bolt

@
and
the

following
parts
can
be

detached
from
heat
control
valve

shaft

Key
00

Counterweight
@

TherI
lostat
spring
CID

Coil

spring

@

Note
As

previously
descnoed
heat

control
valv

1
is

welded
to
valve

shaft

@
at
exhaust
manifold
and

cannot
be

disassembled

To
install

reverse
the
removal

pro

cedure

INSPECTION

I
Run

engine
and

visually
check

counterweight
to

see
if
it

operates

properly

1
For
some
time
after

starling

engine
in
cold
weather

counterweight

turns
counterclockwise
until
it

comes

into
contact
with

stopper
pin
installed

to

exhaust
manifold

Counterweight
gradually
moves

down
clockwise
as

engine
warms

up

and

ambient

temperature
goes
higher

around
exhaust
manifold

2
When

engine
speed
is

increased

discharge

pressure
of
exhaust

gases

causes

counterweight
to

move
down

ward
clockwise

3

When
heat

con
trol
valve
is
in
the

full

open
position
coun

terweight

moves
further
clockwise
exceeding
the
1

Snap
ring

2

Lock
bolt

3

Key

4

Counterweight

5
Thermostat

spring

6
Coil
spring

7

Heat
control
valve

8
Valve
shaft

9
Stove
gasket

10
Manifold
stove

11
Heat
shield

plate

Fig
EC
5

Exploded
view
of
E
F
E
stem

position
described
in
1

1
above

and

stops
again
coming
into
con
tact
with

stopper
pin

j

EC246

1

Counterweight

2
S

topper
pin

3
Heat
control
valve

Fig
EC
6

Operation
of
counterweight

when

engine
is
cold

EC246

1

Counterweight

2

Stopper
pin

3
Heat
control

valve

Fig
EC
7

Operation
of
counterw
ight

when
ngine
is
hot

EC
7
2

With

engine
stopped
visually

check
E
F
E

system
for
the

following

items

1
Thermostat

spring
for
dismount

ing

2

Stopper
pin
for
bend
and
count

er

weight
stop

position
for

dislocation

3

Check
heat
control
valve
for

malfunction
due

to
break
of

key
that

locates
counterweight
to

valve
shaft

4
Check
axial
clearance
between

heat
control
valve
and
exhaust
mani

fold
Correct
clearance
is

0
7

to
1

5

mm
0
028
to
0
059
in

5
Check
welded

portion
of

heat

control
valve
and
valve
shaft
for

any

indication
of
crack
or

flaking

6
Rotate
heat
control
valve
shaft

by
a
finger
and
check
for

binding

between
shaft
and

bushing
in

closing

and

opening
operation
of
heat

control

valve
If

any
binding
is
felt
in

rotating

operation
move
valve

shaft
in
the

rotation
direction
several
times
If

this

operation
does

not
correct

binding

condition
it
is
due
to
seizure
between

shaft
and

bushing
and
exhaust
mani

fold
should
be

replaced
as
an
assem

bly

CHECKING
SPARK

TIMING
CONTROL

SYSTEM

DESCRIPTION

The

spark
tirnin
control

system

serves
to
control
the
distributor
vacu

um
advance
under

varying
travelling

conditions
so
as
to
reduce
HC
and

NOx
emissions

This

system
is
installed
on
non

California
automatic
transmission

models

SPARK
DELAY
VALVE

Automatic
transmission

models
only

This

valve
delays
vacuum

spark

advance

during
rapid
acceleration
it

also
cuts
off
the

vacuwn

spark
advance

immediately
upon
deceleration
The

valve
is

designed
for
one

way
opera

tion
and
consists
of
a
one

way
umbrel

la
valve
and
sinlered
steel
fluidic

restrictor