1977 DATSUN PICK-UP engine

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

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

EC350

Fig
EC
65

Cleaning
E

G
R
control

valve

Thermal

vacuum

valve

Dismount
thermal

vacuum
valve

from

engine

Note
Before

dismounting
drain
en

gine
coolant

from

engine

Apply
vacuum
to
thermal
vacuum

valve
and

check
to
be
sure
thaI
ther

mal
vacuum
valve

opens
or
closes
in

response
to

engine
coolant

tempera

ture
as

specified

Thermal
vacuum
valve

should

open

at
a

temperature
of
57
to
630C

135

to
1450F

completing
the

vacuum

passage

Note
Do

not
allow
water
to

get

inside

the
thermal
vacuum
valve

EC242

Fig
EC
66

Checking
hennal

vacuum

valve
Emission
Control

System

CATALYTIC

CONVERTER

DESCRIPTION

The

catalytic
converter
accelerates

the
chemical
reaction
of

hydrocarbons

HC
and
carbon
monoxide
CO
in

the

exhaust

gas
and

changes
them
into

non
harmful

carbon
dioxide

C02

OPERATION

Exhaust

gas
emitted

from
the
en

gine
contains

some
harmful
substances

due
to

incomplete
combustion
in
the

combustion
chamber
The

air

injection

system
is

designed
to

reduce
the
con

tent
of
such
substances
in

the
exhaust

gas
In

this

system
the

secondary
air

is

led
from
the
check
valve

and

injected

into
the

exhaust
manifold

With
this

injection
of
the

secondary
air

hydro

EC444

EC
26
and
water

H20
This
chemical
reac

tion

process
requires
the

proper
a

mount

of
air

which
is

supplied
by
the

air

pump
Refer
to

the
item
AJ

S

This
air
is
caUed

secondary
air

The

catalytic
converter
is
mounted

on
the

vehicles
destined

for
California
Refer

to

Figure
EC
67

3
4

1
Front
tube

2

Catalyti
converter

3
Center
tube
4
Main
muffler

5
Rear
tube

EC782

Fig
EC
67

Location

of
catalytic
converter

car

ons

He
and
carbon

monoxide

CO
in
the
exhaust

gas
are

gradually

oxidized
with

oxygen
02
in
the

secondary
air
and
converted

into
non

harmful
carbon

dioxide

C02
and

water

H20

The

catalytic
converter

further

cleans

engine
exhaust

gas
Through

catalytic
action
it

changes
residual

hydrocarbons
and
carbon
monoxide

contained

in
exhaust

gas
into
carbon

dioxide

and
water
before

exhaust

gas

is

discharged
to
the

atmosphere

c
Secondary
air

Carbon
monoxide

hydrocarbon

Carbon
dioxide
gas

water

F
EC
68

Operution
of
catalytic
corwerter

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

I
Emission

Control

System

Ignition
switch

Ignition

key
Off

T

I

I

I

Battery

I

J

77

77
Relay

J

Floor

temperature

sensing
swi

tch
Floor

temperature

warning

lamp

77
77

EC332

Fig
EC

70
Win

ng
diagram
of
floor
temperature
warning
system

r
l

J
@

1

Floor

temperature

Ij

cr

EC556

Fig
EC
71
Location

of
iJoor

temperature
sensing
switch

OPERATION

Floor

temperature
will
exceed

nor

mal
level

when

temperature
rise
in

the

exhaust

system
succeeding
the
cata

lytic
converter
is
caused

byeilher
an

engine
malfunction

or
severe

driving

conditions

Under
this
condition
the

floor

temperature
sensing
switch
turns

off

causing
the

starting
switch
line
of

the
floor

temperature
relay
to
turn
off
and
the

ignition
switch
line
to
turn
on

as
a
result
the
floor

temperature

warning

lamp
comes
on

When
the
floor

temperature
is

lower
t

an
the

specific

temperature

the

floor

temperature
sensing
switch

turns

on
The

ignition
line

of
the
floor

temperature
relay
turns
off
while
the

starting
switch
side
is
in

on
The
floor

temperature
warning

lamp
goes
out

EC
2B
The

lamp
is

functioning
sa
tis

factorily
if

it
is
remains
on

while
the

starting
motor
is
in

operation
The

lamp
goes
out
when

the

ignition

switch
is
in

IG

position

The

foUowing
chart

furnishes
the

information
on

the

relationship
be

tween

floor

temperatures

warning

lamp
and

sensing
switch

L

Contact
close

ECJ40

I

Contaclopen

ECJ41

Fig
EC
72

Operation

of
floor

t

mperature
sen6ing

6witch

REMOVAL

Floor

temperature

sensing

switch

1
Remove
seat

Seat
section
of

service
manual

2
Remove

sensing
sWitch
as
outlined
in

the

Body
and
Frame

floor

temperature

Floor

temperature
relay

From
under

relay
cover
remove

this

part
Refer
to

Figure
EC
73

Floortemperature

EC783

Fig
EC
73
Location

of
floor

ttmperature
relay

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

J

1
Fuel
tank

2

Fuel
f1l1er

cap
with

vacuum

relief
valve

3

Liquid
vapor

separator

4

Vapor
vent
line

5
Vacuum

signalUne

As
the
throttle
valve

opens
and

vehicle

speed
increases

vacuum

pres

sure
in

the
vacuum

signal
line
forces

rHL
JL

I

EC785

INSPECTION

FUEL
TANK

VAPOR

LIQUID
SEPARATOR

AND

VAPOR
VENT
LINE

I

Check
all
hoses
and
fuel

tank

mler

cap

2
Disconnect
the

vapor
vent

line

connecting
carbon
canister
to

vapor

liquid
separator

3
Connect
a
3

way
connector

a
Emission

Control

System

Close
at

idling

Open
at
rest

i

J

17
f

Fuel

vapor

6
Canister
purge
line

7
Throttle
valv

8

Engine

9
Carbon
canister

10
Activated
carbon

11

Screen
12
Filter

13

Purge
control
valve

14

Spring

15

Diaphragm

16
Fixed

orifice
i

j

EC784

Fig
EC
77

Evaporative
emu
ion
control

sy
tem

Fuel

vapor
flow
when

engine
i6

at
red
or

idling

the

purge
control
valve
to

open
and

admits
an

orifice
to
intake
manifold

and
fuel

vapor
is

then
drawn
into
the

I

J

o
I

Fuel

vapor

Fresh
air
intake

manifold

through
the
canister

purge
line
See

Figure
EC
7B

Fig
EC
78

Evaporative
emiuion
control

system

Fuel

vapor
flow
when

engine
i

running

manometer
and
a
cock
or
an

equiva

lent
3

way

charge
cock
to

the
end
of

the

vent
line

4

Supply
fresh
air
into

the

vapor

vent
line

through
the
cock
little

by

little
until

pressure
becomes
368

mrnH20

14
5
inH20

5
Shut
the
cock

completely
and

leave
it

unattended

6
After
2
5
minutes

measure
the

height
of
the

liquid
in
the

manometer

7

Variation
of

height
should
remain

EC
31
with
25
mmH20
0
98
inH20

8
When
filler

cap
does
not
close

completely
the

height
should

drop
to

zero
in

a
short
time

9
I
f

the

height
does
not

drop
to

zero
in

a
short
time
when
filler

cap
is

removed
it
is

the
cause
of
a

stuffy

hose

Note
In

case
the

vent
line
is

stuffy

the

breathing
in
fuel
tank
is
not

thoroughly
made
thus

causing
in

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