1977 DATSUN PICK-UP air condition

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

Air
control
valve

CalifornIa
models

The
air
control
valve

con
troIs
the

quantity
of

secondary
air
fed

from
the

air

pump
according
to

engine
speed

and

load
condition
and

prevents
ex

cessive

temperature
rise
of
the

cataly

tic
converter

The
construction
is
as
shown
in

Figure
EC
16
The
intake
manifold

vacuum
and
air

pump
discharge
pres

sure

applied
to

the

diaphragm
chamber

actuate
the

valve
which
is

coupled
to

the

diaphragm
and
control
the

quanti

ty
of

secondary
air
to
be
fed
into
the

exhaust
manifold
in

response
to
the

engine
condition

c
From

air

pump

To

carburetor

air
cleaner

lr

J

EC291

Fig
EC
16
Air
control
valve

Anti
backfire
valve

This

valve
is

con
trolled

by
intake

manifold
vacuum
to

prevent
backfire

in
the

exhaust
system
at

the
ini

tial

period
of
deceleration

At
this

period
the
mixture
in
the

intake
manifold
becomes
too

rich
to

ignite
and
burn
in
the

combustion

chamber
and
burns

easily
in
the
ex

haust

system
with

injected
air
in
the

exhaust
manifold

The
anti
backfire
valve

provides
air

to
the
intake
manifold
to
make
the

air
fuel
mixture
leaner
and

prevents

backfire

A
schematic
drawing
of
the
anti

backfire
valve
is
shown
in

Figure

EC
17

The
anti
backfire
valve
inlet
is

con

nected
to
the
air
cleaner
and
the

outlet

to
the
intake
manifold

Th
correct
function
of
It
jS
valve

reduces
hydrocarbon
emission

during

aeceleration

If
the
valve
does
not
work

properly

unburned
mixture
will
be

emitted
Emission
Control

System

from
the
combustion
chambers
and

burns
with
the
aid
of
high

temperature

and

injected
air

which
causes
backfire

I
Tointake

c
manifold

vacuum

I

L

AirdisChaJ1le

I

to
mtake

manifold
From
air

cleaner

ECQ69

Fig
EC
11
Anti
back
ir
valve

Check
valve

A
check
valve
is
located
in
the
air

pump
discharge
lines
The
valve

pre

ven
ts
the
backflow
of
exhaust
gas

which
occurs
in

one
of
the

following

cases

1
When

the
air

pump
drive
belt

fails
2
When
relief
valve

spring
fails

Construction
is

shown
in

Figure

EC

18

F
rom

m

pump

1

Spring

2

Rubber
valve

3

Seat
Secondary
air

Exhaust

gas

EC292

Fig
EC
1B
Check
valve

AIr

InJaction
Into
axhaust

port

The

secondary
air

fed
from
the
air

pump
goes
through
the

check
valve
to

the
air

gallery
where
it
is
distributed
to

each
exhaust

port
The

secondary
air

is
then

injected
from
the
air

injection

nozzle
into

the
exhaust

port
near
the

exhaust
valve

n

L
y

r

V

Air
pump
relief
valve

The
air

pump
relief
valve

controls

the

injection
of
the

secondary
air
into

the
exhaust

system
when
the

engine
is

EG
11
3
I
Air

gallery

2

Exhaust
port

3
Air

jnjection
nozzle

4
Exhaust

manifold

EC293

Fig
EC
19
Air
injection
into
exhaust

port

running
at

high
speed
under
a

heavily

loaded
condition
It

accomplishes
the

following
functions
without

affecting

the

effectiveness
of
the
exhaust
emis

sion
control

system

Minimizes
exhaust

gas
tempera

lure
rise

2
Minimizes

horsepower
losses
re

suiting
from
air

injection
into
the

exhaust

system

3
Protects

pump
from
excessive

back

pressure

The
air

pump
relief
valve
is
installed

as
shown
in

Figure
EC

20

The

secondary
air
is

discharged

from
the
air

pump
relief
valve

to
the

dust
side
of
the
carburetor
air
cleaner

To
carburetor

air
cleaner

Secondary

air

To
carburetor

air

cleaner

J
erCOndary

r

r

EC294

Fig
EC
20
Air

pump
relief
valve
Emission
Control

System

Emargency
air
retial
valve

E
A
R
Valve

California
models

The

emergency
air
relief
valve
con

trols
the

quantity
of
secondary
air

fed

from
the
air

pump
according
to

load

condition
and
it

discharges
the
see

ondary
air
into
the

atmosphere
to

prevent
overheating
of
the

catalytic

converter

The

emergency
air
relief
valve
con

sists
of
a

diaphragm
a

spring
and

a

valve
which
is

coupled
to

diaphragm

1

Diaphragm

2

Val

3

Spring

4

Diaphragm
chamber

EC536

Fig
EC

21

mergency
air

relief
valve

OPERATION

As
mentioned

previously
there

are

two

types
of
Air

Injection
Systems

A
I

S
a

non
California

type
and
a
California

type
The
California
stand

ard

type
includes
a

system
which

controls

injection
of

secondary
air

so

as
to
assure

proper
function
of
the

catalytic
converter
and
a

system

which
controls
the

supply
of
second

ary
air
to

prevent
abnormal

tempera

tUfe
rise
in
the

catalytic
converter

The
A
I
S
consists
of
the

following

systems

L
A

system
which
allows

injection

of

secondary
air
into
the
exhaust

port

2
A

system
which

bypasses
sec

ondary
air

from
the
air

pump
relief

valve

to
the

carburetor
air

cleaner

during

high
speed
engine
operation

3
A

system
which

supplies
air

from

the
carburetor
air
cleaner

to
the
intake

manifold

by
means
of
the
anti

backfire

valve
so
as
to

prevent
after
fire

during

deceleration

4
A

system
which

controls

injection

of
the

secondary
air

by
means
of
the

air

control
valve

so
as
to
maintain
the

catalytic
converter
at
an

optimum

temperature
level
under

lightly
loaded

condi
tions

Califomia

type
only

5
A

system
which
controls
the

sup

ply
of

secondary
air

through
the
emer

gency
air

relief
vilve

io
pfevent
ab

normal

temperature
rise
of
the

cataly

tic

converter

California

type
only

A
I

S

operation
is

as
follows

I

I

t

1
r

9

I
Air

pump
6

Check
valve

I
0
L
2
Air

pump
air
deaner
7
Air

gallery
pipe

3
Air

relief
valve
8
Injection
non
e

r
4
Air
cleaner
9

Exhaust
manifold

5

Carburetor
10

Anti
backflIe
valve

EC179

Fig
EC
22
Non

California
type
A
I
S

EC
12

Ignition
Switch
Position
START

Detector
Drive

Counter

E
G
R

Warning
Lamp
ON

b
After

completing
inspection
of

E

G
R

control
system
be

sure
to

reset

odometer
of
detector
drive

counter
to

zero

c
This
item

applies
to
all
620
models

except
those
bound
for
California

and
Canada

3

With

engine
stopped
inspect

E
G
R
control
valve
for

any
indication

of

binding
or

sticking
by
moving
dia

phragm
of
control
valve

upwards
with

a

finger

2
When

engine
coolant

tempera

ture
is

high

I
Make

sure
that
E

G
R

control
valve

operates
when

engine
speed
is
in

creased
from
idling
to
3
000
to

3
500

rpm
Place
a

fmger
on
the

diaphragm
of
E
G
R
control

valve

to
check
for
valve

operation

2
If

E
G
R
control
valve
does
not

operate
check

as
follows

Disconnect
one
end
E

G
R
control

valve
side
of
vacuum
hose
connect

ing
thermal
vacuum
valve
to
E
G
R
Emission
Control

System

ON

Below

50
000
counts
Above

50
000
counts

OFF
ON

4
With

engine
running
inspect

E
G
R

control
valve
and
thermal
vacuo

um
valve
for
normal

operation

1
When

engine
coolant

tempera

ture

is
low

Make

sure
that
E
G
R

control
valve

does
not

operate
when

engine
speed
is

increased
from

idling
to
3
000
to

3
500

rpm

Place
a

fmger
on
the

diaphragm
of

E
G
R
control
valve
to

check
for
valve

operation

EC253

Fig
EC
62

Checking
E
G
R
control
valve

control
valve

Increase

engine
speed
from

idling
to

3
000
to
3

500

rpm

Make
su
re
that
thermal
vacu
um

valve
is

open
and
that

carburetor

vacuum
is

present
at
the
end

E

G
R
control

valve
side
of

vacu

um
hose

If
vacuum
is
weak
or

not

present
at

all

replace
thermal
vacuum
valve
If

vacuum
is

present
replace
E
G

R

control
valve

EC
25
EC254

Fig
EC

63

Checking
lhermal

vacuum
valve

If

any
difficulty
is
encountered
in

judging
the
condition
of

any

compo

nent

during
above

inspection
check

the

questionable
component
independ

ently
as

follows

E
G
R

control
valve

Dismount
E

G
R

control
valve

from

engine

I

Apply
vacuum
to

E
G
R

control

valve

referring
to
the

following
figure

If

the
valve

moves
to
full

position
it
is

normal

E
G
R

control
valve
will
remain

open
for
more

than
30

seconds
after

vacuum
has
cut

off

la

ET152

Fig
EC
64

Checking
E
G
R

control

ualue

2

Visually
check
E
G
R

control

valve
for

damage
wrinkle
or
defonna

tion

3

Clean
the

seating
surface
of

E
G
R
control
valve
with
a
brush

and

compressed
air

and
remove

foreign

matter
from
around
the
valve
and

port

REMOVAL

AND

INSPECTION

Removal
and

inspection
can
be

done

as
follows

Removal

Catalytic
converter

1

Apply
parking
brake

2

Place
wheel
lock
under
each
tire

3

Jack

up
the
vehicle

4
Remove
lower
shelter
of

catalytic

converter

5
Dismount

catalytic
converter

EC453

Fig
EC
69
Removing

catalytic

conuerter

Inspection

Preliminary
inspection

Visually
check
condition
of
all

component
parts
including

ho
s

tubes
and
wires

replace
if

necessary

Refer
to

Inspection
of
A
I
S
on

page
EC
17

Catalytic
converter

Whether

catalytic
converter
is
nor

mal
or
not
can
be
checked
by
ob

serving
variation
in

CO

percentage

The

checking

procedure
is

as
follows

Apply
parking
brake
Shift

gears

into
Neutral
for
manual
transmission

and
Neutral
or
Park
for
automatic

transmission

1

Visually
check

catalytic
converter

for

damage
or
cracks
Emission
Control

System

2
Remove
air
hose
between

5

way

connector
and
air
check
valve

Plug
the

disconnected
hose
to

prevent
dust

from

entering
Refer
to

page
ET
12

3

Check
carburetor

pipes
for

proper

connection

4

Warm

up
engine
sufficiently

5

Race

engine
1

500
to
2
000

rpm

two
or
three
times

under
no
load
then

run

engine
for
o
e
minute
at

idling

speed

6

Adjust
throttle

adjusting
screw

until

engine
attains
to

specified
speed

Refer
to

page
ET
10

7
Check

ignition
timing
If
neces

sary
adjust
it
to

specifkations
Refer

to

page
ET
10

B

Adjust
idle

adjusting
screw
until

specified
CO

percentage
is

obtained

Refer
to

page
ET
12

9

Repeat
the

adju
stment

process
as

described
in

steps
5
to
8
above

until

specified
CO

percentage
is
obtained

Note

Adjustment
in

step
9
should
be

made
ten

minutes
after

engine
has

wanned

up

10
Race

engine

1
500
to
2
000

rpm
two
or
three
times

under
no
load

and
make
sure
that

specified
CO

per

centage
is
obtained

11
Remove

cap
and
connect
air

hose
to

air
check
valve

If

idling

speed
increases

readjust
it

to

specified
speed
with
throttle
ad

justing
screw

12
WaRn

up
engine
for

about
four

minutes
at
2
000

rpm
under
no
load

13
Measure
CO

percentage
at

idling

speed
After

step
12
has
been
coin

pleted
wait

for
one
minute
before

making
CO

percentage
measurement

14
If
CO

percentage
measured
in

step
13
is
less
than
0
3

the

catalytic

converter

is
normal

15
If
CO

percentage
measured
in

step
13
is
over
0
3

recheck
A
I
S

and

replace
air
check
valve
Then

perform
inspection
steps
12
and
13

EC
27
16
If
CO

percentage
is

still
over

0
3
in

step
15

catalytic
conyerter
is

malfunctioning
Replace
catalytic
con

verter

INSTALLATION

To
install

reverse
the
removal

pro

cedure

Bolt

lightening

torque

specifications

Tightening

torque

Catalytic
converter

2
6
to
3
4

kg
m

19
to
25
ft
Ib

FLOOR

TEMPERATURE

WARNING
SYSTEM

DESCRIPTION

The
floor

temperature
warning

system
consists
of
a
floor

temperature

sensing
switch
installed

on
the
vehi

cle
s
floor
floor

temperature
relay
and

a

warning

lamp
on
the
instrument

panel
and
wires
that
connect
these

parts

When
the
floor

tempera
ture
rises
to

an
abnormal
level
the

warning
lamp

will

light
to
call
the
attention
of
the

driver
The

wiring
diagram
of
this

system
and
location
of
the

floor

temperature
sensing
switch
are
ilIus

trated
in

Figures
EC
70
and
EC
71

sufficient

delivery
of
fuel
to

engine

or

vapor
lock
It
must
therefore
be

1

3
connectur

COCk

Air
Manometer
Emission
Control

System

repaired
or

replaced

368
mmH20

14
5
inH20

LL

IPO
liqUid
epo
o

36

r
@

Carbon
canister

EC786

Fig
EC
79

Checking

evaporative
emmion

control

syatem

CARBON

CANISTER
PURGE

CONTROL
VALVE

Check
for
fuel

vapor
leakage
in

the

distributor
vacuum
line
at

diaphragm

of

carbon

canister

purge
control
valve

To

check
for

leakage
proceed
as

follows

I

Disconnect
rubber
hose
in

the

line

between
T
connector

and
carbon

canister
at
T

connector

2

Inhale
air
into
the

opening
of

rubber
hose

running
to

vacuum
hole
in

carbon

canister
and

ensure
that
there

is
no

leak

ET349

Fig
EC
so

Checking
carbon
canuter

purge
control
valve
3
If
there
is

a
leak

remove

top

cover
from

purge
control
valve

and

check
for
dislocated

or
cracked
dia

phragm
If

necessary

replace
dia

phragm
kit

which
is
made

up
of
a

retainer
a

diaphragm
and
a

spring

@

@

1
Cover

2

Diaphragm

3
Retainer

4

Spring

ET350

Fig
EC
81
Carbon

catU
ter

purge

control
valve

CARBON

CANISTER
FILTER

Check
for
a
contaminated

element

Element

can
be
removed

at
the

bottom
of

canister

installed
on
vehicle

body

EC
32
ET37Q

Fig
EC
s2

Replacing
carbon

canuter

filter

FUEL
TANK

VACUUM

RELIEF
VALVE

Remove
fuel
filler

cap
and
see
it

functions

properly

I

Wipe
clean
valve

housing
and
have

it
in

your
mouth

2

Inhale
air
A

slight
resistance
ac

companied
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
is

clogged
or
if

no
resist

ance
is

felt

replace
cap
as
an
assem

bled

uni
t

l

u

ET369

Fig
EC

83
Fuel

filler
cap

Engine
Electrical

System

SERVICE
DATA
AND
SPECIFICATIONS

Type

System
voltage

No
load

Terminal

voltage

Current

Revolution
v

V

A

rpm

Brush

length
Outer
diameter
of
commutator
mm
in

mm
in

Brush

spring
tension

kg
Ib

Clearance
between

bearing
metal
and

armature
shaft
mm
in

Clearance
L
between

pinion
front

edge
and

pinion
stopper
mm
in

TROUBLE
DIAGNOSES
AND
CORRECTIONS

Condition

Starting
motor
will

not

operate

Noisy
starting
motor

Starting
motor

cranks

slowly
Probable
cause

Discharged
battery

Damaged
solenoid
switch

Loose
connections
of
terminal

Damaged
brushes

Starti

g
motor

inoperative

Loose

securing
bolt

Worn

pinion

gear

Poor

lubrication

Worn
commutator

Worn
brushes

Discharged
battery

Loose
connection
of
terminal

Worn
brushes

Locked
brushes

EE
ll
Manual

transmission
Automatic

transmission

Optional

for

manual

transmission

SII4
ISOB

S114
170B

12

12

Less
than

60

More

than
7

000
More
than
6
000

More
than
39

1
54

More
than
12
0
47

1
4

to
I
S
3
1
to
4
0

Less
than

0
2
O
OOS

0
3
to
1
5
0
012
to
0

059

Corrective
action

Charge
or

replace
battery

Repair
or

replace
solenoid
switch

Clean
and

tighten
terminal

Replace
brushes

Remove

starting
motor
and
make
test

Tighten

Replace

Add
oil

Replace

Replace

Charge

Clean
and
tighten

Replace

Inspect
brush

spring
tension

or

repair
brush

holder

Condition
Engine
Electrical

System

Probable
cause

Starting
motor

cranks

slowly
Dirty
or
worn
commutator

Armature
rubs

field
coil

Damaged
solenoid
switch

Starting
motor

operates
but
does

not
crank

engine
Worn

pinion

Locked

pinion
guide

Worn

ring

gear

Starting
motor
will

not

disengage
even
if

ignition
switch
is

turned
off
Damaged
solenoid
switch

Damaged

gear
teeth

The

charging
circuit
consists

of
the

battery
alternator

regulator
and

necessary

wiring
to
connect
these

parts
The

purpose
of
this

system
is
to

convert
mechanical

energy
from
the

engine
into

electrical

energy
which

is

used
to

operate
all

electrically

operat

ed
units

and
to

keep
the

battery
fully

charged

When
the

ignition
switch
is

set
to

ON
current
flows
from
the

battery

to

ground
through
the

ignition
switch

voltage
regulator
IG
terminal

primary

side
contact

point
PI

movable

contact

point
P2

voltage

regulator

IF

terminal
alternator
IF
terminal

rotor

field
coil
and
alternator

E

terminal

as
shown
in

Figure
EE

23

by

full
line

arrow
marks
Then
the

rotor

in

the

alternator
is
excited

On
the

other
hand

current
flows

from
the

battery
to

ground

through
the

ignition

switch

warning

lamp
voltage
regula

tor
L

terminal

lamp
side
contact

point
P4

movable

contact

point

P5
and

voltage
regulator
E
termi

nal
as
shown

by
dotted

line
arrow
CHARGING
CIRCUIT

marks
Then

the

warning
lamp
lights

When
the
alternator

begins
to

op

erate
three

phase

alternating
current
is

induced
in

the

stator
armature
coil

This

alternating
current
is
rectified

by

the

positive
and

negative
silicon

diodes
The
rectified

direct
current

output
reaches
the
alternator
A

and

E

terminals

On
the
other
hand
the
neutral

point
voltage
reaches
N
and
E

terminals

nearly
a
half
of

the

output

voltage
and
current
flows
from

voltage
regulator
N
terminal
to
E

terminal
or

ground
through
the
coil

VCI
as
shown
in

Figure
EE
24

by

the
dotted
line
arrow
marks
Then
the

coil
VCI
is
excited
and
the

movable
contact

point
IPS
comes

into
contact
with

voltage
winding
side

contact

point
P6
This
action
causes

to
turn
off

the

warning
lamp
and

complete
the

voltage
winding
circuit

as
shown

by
the
full

line
arrow
marks

When
the
alternator

speed
is
in

creased
or
the

voltage
starts
to
rise

excessively
the
movable
contact

point

EE
12
Corrective
action

Clean
and

repair

Replace
assembly

Repair
or

replace

Replace

Repair

Replace

Repair
or

replace

Replace
damaged

gear

P2
is

separated
from

the

primary

side
contact
PI

by
the

magnetic

force

of
coil
VC2
Therefore

registor
RI
is

applied
into
the
rotor

circuit

and

output
voltage
is
decreased

AJ

the

output
voltage
is
decreased

the

movable
contact

point
P2
and

primary
side
contact
Pin

comes
into

contact
once

again
and

the
alternator

voltage
increases

Thus
the

rapid

vibration
of
the
movable

contact

point

IPl

maintains
an
alternator

output

voltage
constant

When
the
alternator

speed
is

further

increased
or
the

voltage
starts
to
rise

excessively
the

movable
contact

point

P2
comes

into
contact
with

secondllJ
side
contact

point
P3

Then
the
rotor
current
is

shut
off
and

alternator

output
voltage
is

decreased

immediately
This

action
causes

movable
contact
n
to

separate

from

secondary
contact
P3
Thus

the

rapid
vibration
of

the
movable

contact

point
P2

or

breaking
and

completing
the

rotor
circuit
maintains

an
alternator

output
voltage
constant