1977 DATSUN PICK-UP oil

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

Emission
Control

System

C
bur
tor

I

EC284

When

installing
this
valve

ensure

that
it

properly
oriented
Tlus
valve

shuuld
be

replaced
periodically
Refer

to
Maintenance
Schedule

Note
Carburetor
side
Black

DisInDutor
side

Brown

horn
distributor

To

carburetor

TOdi

ribUI0
carburClor

EC
lCiJr

Fig
EC

9
Operation
01

park
delay

value

INSPECTION

Remove

spark
delay
valve

2
Blow

air

through
port
on
carbure

tor

side
then

through
the

other

port

on
distributor
side

Spark
delay
valve
Distributor
side

1
One
way
umbrella
valve

2
Sintered
metal

disc

Fig
EC
8

Spark
delay
valve

is
in

good
condition
if
when

finger
is

placed
over

port
on
distributor
side

air

flow
resistance
is

greater
than
that

on
the

other
side
See

Figur
ET
lO

3
If
a

considerable
air
flow
resist

ance
is

fell
at

port
on
distributor
side

in

step
2

above
and
if

the
condition
of

spark
delay
valve
is

questionable
dip

port
on
carburetor
side
into
a

cup

filled
with

water
Blow
air

through
the

other

port
Small
air
bubbles
should

appear

Carburetor
side

Distributor
side

EC346

Fig
EC
IO

Checking
park
delay
valve

EC
8
EC219

Fig
EC

11

Checking
spark
d

tay
valve

Note
Be
careful
to
avoid

entry
of
oil

or
dirt
into
valve

AIR
INJECTION

SYSTEM

DESCRIPTION

The
Air

Injection

System
A

LS
is

aeSigiieino

iiiject
coin

pressed
air
sec

ODllary
air

corning
from
the
air

pump

into
the
exhaust
manifold
to
reduce

hydrocarbons
and
carbon
monoxide
in

exhaust
lri
s

through
re
combustion

There

are
two

types
of
A

I

S
One

type
is
mounted
on
California
models

and
the
other
is
on
non
California

models
The
non
California

type
con

sists
of
an
air

pump
air

cleaner
an
air

pump
a
relief

valve
a
check
valve
an

anti

backfIre
valve
an
air

gallery
and

hoses
The
California

type
has
in

addition
to
the

components
of
the

non
California

type
an
air
control

valve
and

an

emergency
air
relief
valve

These
valves

prevent
ahnonnal
tem

perature
rise
of
the

catalytic
converter

9
From
air

pump

l

h
1

Not
actuated

REMOVAL
AND

INSTALLATION

Air
p
mp
sir
cleaner

Remove
air
hose

then
detach
air

cleaner

from

hoodledge
Air
cleaner

element
and
Ii
r
deancr
lower

body
are

built
into
a
unit
construction

Replace

air
cleaner
clcl

nen
and

lower

body
as

an

assembly

J

J

tt
c

t
o

J

EC
323

Fig
EC
26
Replacing
oir
cleaner

element

Air

pum

Remove
air
hoses

from
air

pump

2
Loosen
air

pump
adjusting
bar

mounting
bolts
and
air

pump
mount

ing
bolts
then

remove
air

pump
drive

bell

3
Remove
air

pump
pulley

4
Remove
air

pump
from
bracket

Air
control
valve

California
models

l
Disconnect

air
hoses
and
a
vacu

um
hose
from
air
control
valve

2
Remove
air
con
trol
valve
from

bracket

E
A

R
valve
California
modela

Remove
vacuum

pipe
and
air

hose

and
dismount
E

A
R
valve
Emission
Control

System

o

jJ
To

Intake
mamfold

rF
vacuum

r

To
air

cleaner

From
air

pump

EC781

Fig
EC
27
Locotion

of
E
A
R
wive

Antl
backflravalve

Disconnect
air
hose
and
vacuum

hose
from
anti
backfire
valve

Check
valve

Disconnect
hose
and
remove
check

valve
from
air

gallery
pipe

Air

ganery
pIpe
andinJactlon

nozzles

It
is

very
difficult
to
remove
the
air

gallery
from
the
exhaust
manifold

without

bending
the

pipe
which
could

result
in
fractures
or

leakage
There

fore

removal
of

the
air

gallery
pipe

and

injection
nozzles
should
be
under

taken

only
when

they
are

damaged

I
Lubricate
around
the

connecting

portion
of
air

injection
nozzle
and
air

gallery
with

engine
oil

2
Hold
air

injection
nozzle

hexagon

head
with
a

wrench
and
unfasten
flare

screw

connecting
ait

gallery
to

injec

tion
nozzle
Remove
air

gallery

EC
14
To
intake

manifold

vaCUl
lm

r

Y

4
9
Gf

T

I
To

air
cleaner

I

Actuated

EC299

Fig
EC
25

Operation
of
air
control
value

Notes

a

Apply
engine
011
to
rews
several

times
during
above

work

b
Be
atreful
not
to

damage
other

parts

3
Unfasten
air

injection
nozzle

from

cylinder
head

applying
engine
oil

to
screwed

portion
several
times

4

Check
air

gallery
and
nozzle
for

fractures
or
leakage
Clean
air

injection

nozzle
with
a
wire
brush

5

At
time
of
installation
hold
air

injection
nozzle

hexagon
head
with

a

wrench
and

tighten
air

gallery
flange

screw
to
a

torque
of
5
0
to
5
9

kg
m

36
to
43
ft
lb

6
Check

cylinder
head
air

injection

nozzle
and
air

gallery
for
leaks
with

engine
running

Air

pump
relief
vslve

Loosen
carburetor
air
cleaner

mounting
sc
ews
and

remove
air

pump
relief
valve

InstallatIon

Install
in
the

reverse
order
of
reo

moval

DISASSEMBLY
AND

ASSEMBLY

Disassembly
of
air
pump

1
Remove
four

pulley
drive
bolts

and
remove

pulley
from
hub

2

Secure
air

pump
drive
hub
in

a

vise

as
shewn
in

Figure
EC

28
and

remove
four
end
cover
bolts

j

EC231

Thermal

vacuum
valva
o

o

m
Emission

Control

System

0

o

o

o

l

l
@

The
thermal
vacuum
valve

is

mounted
in

the

engine
thermostat

housing
It

detects

engine
coolan
t

tem

perature
by
means
of
a

built
in

bi

metal
and

opensor
closes
the

vacuum

passage
in
the

thermal
vacuum

valve

mt

li

t

00
t

EC232

Fig
EC
54
Thennal

vacuum
valve
To
E

G
R
control
valve

From
carburetor

1

Spring

2
Bi
metal

3

O

ring

E
G
R

warning

system

The

E
G
R

warning
system
install
1

Diaphragm
spring

2

Diaphragm

3
Valve
shaft

4

Valve

5
Valve

Seat

6
Valve
cham
ber

Fig
EC
53
E
G

R
control
value

When
the

vacuum

passage
is

open
the

carburetor
suction

vacuum
is

applied

to
the

diaphragm
of
the
E
G
R

con

trol
valve
to

actuate
the

taper
valve

connected
to
the

diaphragm

theconsiiiictlo

nlie
thermal

vacuum
valve
is

shown
below

ed

independently
of
the

E
G
R

con

trol

system
monitors

the
distance
the

car
has
travelled
and

indicates
when

EC
22
the
E

G
R

control

system
must
be

checked

The
E
G
R

warning
system
consists

of

an
odometer
switch

detector
drive

counter
E

G
R

warning

lamp
and

harnesses

When
the

earn
in
the

odom

eter
switch
connected
to

the

speed

ometer
turns

once
for

each
OAkm
4

mile
the

contact

point
of
the
elec

trica
circuit
closes

allowing
electric

current
to
flow

through
the

magnet

coil
of

the
detector

drive
counter

Thus

energized
the

magnet
coil
ac

Wates

the
latchet
to

turn
the
c
unter

wheel

by
one

pitch
When
the

number

of

counts
reaches
50
000
the
latchet

drops
in

a

groove
provided
on
the

periphery
of

the
counter
wheel
to

activate

the
detector

drive
counter

switch

Then
the

E
G
R

warning

lamp

comes
on

indicating
that
the
E
G
R

control

system
Should
be
checked

The

detector
drive

coun
teT
is

equip

ped
with
an
odometer
which

can
tell

when
to
service

the
E

G
R
contr0
I

system

After

completing

periodic
check

reset
the
odometer
to

zero
by
hand

proceeding
as
follows

1
Remove

grommet
installed
on

the
side

surface
of

detector
drive

counter
unit

2
insert

a
bar

or
a
screwdriver

tip

into
the

hole
from

which

grommet
has

been

removed
and

press
down
knob

provided
in

the
detector
drive
counter

for

resetting

The
E

G
R

warning

lamp
comes

on

under
the

following
circumstances

1
When
the
number
of

counts
has

reached
50
000
In
this

case
the

lamp

indicates
that
E

G
R

control

system

must
be
checked

2
When

operating
starter
motor

Notes

a
It
is

an
indication
of

problem
in

the

E

G
R

warning
lamp
or

problems

in
the

point
or
in
the
harnesses
if

the

lamp
does
not

light
at

50
000

counts

b

The
E

G
R

warning
system
is

mounted

on
all
620
models

except

those

bound
for
California
and

Canada

1

1

I
I

I

1
v

v

I
I

I
I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

L
0

I

Magnet
coil

Detector
drive

counter

REMOVAL
AND

INSTALLATION

Remove
air
cleaner

before

removing

E
G
R
control

system
For
removal

and

installation
of
air

cleaner
refer
to

Air
Cleaner
section

Page
EF
S

Removal

I
E
G
R
control
valve

After

removing
the

following
parts

the
E

G
R

controi
valve
can

be
dis

mounted

Vacuum

hose
thermal
vacuum

valve
to
E
G
R

control
valve

E
G
R
control
valve

mounting
nut

Note
To
remove

vacuum
hose
flat

ten

clip
connecting
vacuum
hose
to

E
G
R
control
valve
and

pull
the

hose
off
with
hand
Emission
Control

System

Ignition
switch

E
G
R

warning
lamp

f

1
Ignition
switch

start

position

Fuse

1
A
Odometer
switch

r

I
I

I

I
v

I

I
I

i

lQ
U

1

mi

L
J

EC233

Fig
EC
55
E
G
R

warning
circuit

EC234

Fig
EC
56

Removing
KG
R
control

valve

2
E
G
R

pass
ge

After

removing
the

following

parts

the
E
G
R

passage
can
be
dismounted

Exhaust
gas
return

tube
exhaust

manifold

to
E
G
R

passage

B1ow

by
hose

cylinder
block

to

P
C
v
valve

Vacuum
hose
AB
valve
to
E
G
R

passage

E
G
R

passage
mounting
bolt

EC

23
EC541

Fig
EC
57

Removing
E
G
R

passage

3

Thermal
vacuum

valve

After

removing
the

following

parts

the
thermal
vacuum
valve
can
be
dis

mounted

Vacuum
hose

carburetor
to
ther

mal
vacuum
valve

Vacuum
hose
thermal
vacuum

valve

to
E

G
R
control
valve

Note
Drain

engine
coolant
before

dis

mounting
thermal
vacu
m
valve

Fig
EC
58

Removing
thermal

vacu
um
valve

4
E
G
R

warning
system

EC251

Detector
drive
counter

Detecfor
drive
counter
is
secured

on
the

top
of
R
H

hoodledge
panel
in

engine
room
To

remove
detector
drive

counter
disconnect
w
COJUlector

and

loosen
two
bolts

securing
detector

drive
counter
to
hoodledge

panel

2

E
G
R

warning
lamp

E
G
R

warning
lamp
is
mounted
at

the

top
cen
ter
of
instrument

pad
To

remove
E
G

R

warning
lamp
proceed

as
follows

1
Remove

masking
panel

On
models

equipped
with
radio

remove

warning
lamp
from
under
in

strument

panel

2

E
G
R

warning
lamp
is

a
twist

type

Remove

lamp
and
socket

as
an

assembly
Push
and
twist

lamp
off

can

EC554

Fig
EC
60
Removing
E
G
R

warning

lamp
Emission
Control

System

3
Odometer
switch

Odometer
switch
is
mounted
on
the

back
side
of

speedometer
Cam
in
the

odometer
switch
is
rotated

by
the

speedometer
To

dismount
odometer

switch

proceed
as
follows

I

Dismount
combination
meter
as

sembly

2
Remove
meter
front
cover
and

take
off

clips
and
screws
to

dismount

shadow

plate

3

Loosen
screws

securing
speed

ometer
to

printed
circuit

housing
then

remove

speedometer

4

Remove
two
screws

securing

odomete
switch
to
the

back
side
of

speedometer
and
detach
odometer

switch

EC239

Fig
EC
61

Removing
odometer

switch

InstaUatlon

To
install
reverse
the
removal

pro

cedure

EC24
V

r
CID

1
Detector
drive
counter

2
E
G
R
warning
lamp

3
Speedometer

Fig
EC
59
E
G
R

warning
y
tem

INSPECTION

Checking
E

G
R
control

system
in

its
mounted
conditionS

I

Make
a

thorough
visual
check
of

E

G
R
control

system
If

necessary

wipe
away
oil
to

facilitate

inspection

If

any
hoses
are
cracked
or

broken

replace

2

With

engine
running
check

E

G
R

warning
system
for

proper

function
Make
sure
that
E

G
R
warn

ing
lamp
lights
when

ignition
switch
is

turned

to
START

position
starter

mo

tor
runs
If
E
G
R

wanung
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
odomete
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
connectors
and
de

tector
drive
counter
replace
warning

lamp
or
detector
drive
counter
if

necessary

Notes

Operation
oC
E
G
R

warning
lamp

is
as
Collows

3

Check

ignition
system
with

regard

to

the

following
items

Refer
to

Inspection
of

Ignition
System

1

Ignition
AMP

2
Distributor
Emission
Control

System

3

Ignition
coil

4

High
tension
code

5

Spark

plug

4

Check
idle

CO

adjustment
Refer

to

Inspection
of
Idle

CO

Adjustment
Note
Even
if
there
is

nothing

wrong

with

engine
the

warning
lamp
may

come
on
if
vebicle
is

being
driven

on
a

steep
slope

continuously
in

lower

gears
at

high
engine
speeds

EVAPORATIVE

EMISSION

CONTROL
SYSTEM

CONTENTS

DESCRIPTION

OPERATION

INSPECTION

FUEL
TANK

VAPOR
LIQUID

SEPARATOR

AND

VAPOR
VENT
LINE

DESCRIPTION

The

evaporative
emission
control

system
is

used
to

reduce

hydrocarbons

emitted
to
the

atmosphere
from
the

fuel

system
This

reduction
of

hydro
EC
30

EC

30

EC

31
CARBON

CANISTER
PURGE
CONTROL

VALVE

CARBON
CANISTER

FILTER

FUEL

TANK

VACUUM
RELIEF
VALVE
IEC
32

IEC
32

EC

32

EC
31

carbons
is

accomplished
by
activated

charcoals
in
the
carbon
canister

This

system
is
made

up
to

the

following

I

Fuel
tank
with

positive

sealing
filler

cap

@
2

Vapor
liquid
separator

3

Vapor
vent

line

4
Carbon

canister

5
Vacuum

signal
line

6
Canister

purge
line

5

OPERATION

Fuel

vapors
from

the
sealed
fuel

tank
are
led

into
the
carbon
canister
1
Fuel
tank

2
Fuel
nIler

cap
with
vacuum

relief

valve

3

liquid

vapor
separator
4

Vapor
vent
line

5

Canister

purge
line

6
Vacuum

signal
line

7
Carbon

canister

EF274

Fig
EC
76

Schematic

drawing
of
l
Iaporotive

emiaion

control6ydem

The

canister
is
fined
with
activated

charcoals

to
absorb

the
fuel

vapors

EC
30
when
the

engirie
is

at
rest
or
at

idlin
ll

See

Figure
EC

77