1977 DATSUN PICK-UP coolant temperature

6

Thermal
vacuum
valve

Open

E
G
R
control
valve
Close

E
G
R
ON

operation

The
E
G
R
circuit
is

completed

only
when

engine
coolant

temperature
Emission
Control

System

I

I
Note
Vacuum
condition

EC793

Fig
EC
51
E
G
R
not
actuated

is
above
the

working
temperature
of

the

thermal
vacuum
valve
and
carbu
retor
suction
vacuum
is

large
enough

to

open
the
E
G
R

control
valve

Y
m
l

fj

t1f
1t
3
0

l

P
@
0
f
Y
f

1
i0
W
g

1
i3
iiA
d

m

E
N
ti

n
k

i

l
i
Throttle
valve

n

L
r

E

G
R

control
valve

Open

E
G
R
control
valva

The

E
G
R

control
valve
controls

the

quantity
of
exhaust

gas
to
be
led

to
the

intake
manifold

through
vertical

movement
of
the

taper
valve
connect

ed

to
the

diaphragm
to
which

vacuum
Thermal
vacuum

valve

Open

Note

iiiI
Vacuum
condition

EC794

Fig
EC
52
E
G
R
actuated

is

applied
in

response
to
the

opening

of
the
carburetor
throttle
valve
The

E
G
R
control
valve
is
installed
on
the

E
G
R

passage
through
a

gasket

E
G
R
con
trol
valve
construction

and

type
vary
with

transmission

type
and

car
destination
For
identification

purposes
the

part
number
is

stamped

on
the
recessed

portion
at
the

top
of

the
valve

The

construction
of
the
E
G
R

control
valve
is

shown
below

EC
21

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

Using
the

tester
check
the

two

black

yellow
BY
wires
from
the
in

hibitor
switch
in
the

ranges
N

and

I
and
the

tw
re
d

black

RBj
wir
s

in

the

range
R
for

continuity
Turn

range
select
lever
in
both

directions

from

each
lever
set

position
and
check

each

continuity

range
It

is
normal
if

the

electricity
is

on
while
the
lever
is

within
an

angle
of
about
30

on
both

sides
from
each
lever
set
line
How

ever
if
its

continl
ity

range
is
obvious

ly
unequal
on

both
sides

adjustment
is

required

If

any
malfunction
is

found
un

screw
the

fastening
nut
of
the

range

selector
lever

and
two

fastening
bolts

of
the
switch

body
and
then
remove

the
machine
screw
under
the
switch

body
Adjust
the
manual
shaft
correct

ly
to
the

position
N

by
means
of
the

selector
lever

When
the

slot
of
the

shaft

becomes
vertical
the
detent

works
to

position
the
shaft

correctly

with
a

clicking
sound

MSlVe
the

switch

slightly
asj
Je
so

that
the
screw
hole
will
be

aligned

with
the

pin
hole
of
the
internal
rotor

combined
with
the
manual
shaft
and

check
their

alignment
by
inserting
a

1
5
mm
0
059
in
diameter

pin
into

the
holes
If

the

alignment
is
correct

fasten

the
switch

body
with
the
bolts

pull
out
the

pin
tighten

up
the
screw

in

the
hole
and
fasten
the
selector

lever
as
before
Check
the

continuity

again
with
the
tester
If

the
malfunc

tion
still

remains

replace
the
inhibitor

switch
Chcck
whether
the

reverse

lamp

and
the
starter
motor

operate
normal

ly
in
these

ranges
If
Ihere
is

any

lrouble

first
check
the

linkage
If

no

fault
is
found
in

the

linkage
check
the

inhibitor
switch

Separate
the
manual
lever
from
Ihe

remote
control
selector

rod
and
turn

the

range
selcct

lever
to

N

Note

In
the

position
N

the
slot
of

the

manual
shaft

is
vertical

STALL
TEST

The

purpose
of
this
test
is
to
check

the
transmission

and

engine
for
trou

ble

by
measuring
the
maximum
num

bers
of
revolutions
of

the

engine
while
Automatic

Transmission

vehicle
is
held
in
a

stalled

condition

The
carburctor
is
in

full
throttle

opera

tion
with

the
selector
lever
in

ranges

f
2

and
I

respectively
Com

pare
the

measured
results
with
the

slandard

values

Components
to

be
tested

and

test

items

I
Clutches
brake

and
band
in
trans

mission
for

slipping

2

Torque
converter

for

proper
fune

tioning

3

Engine
for
overall

properly

STALL
TEST

PROCEDURES

Before

Icsting
c
heck
the

engine
oil

and

torque
converter

oil
warm

up
the

engine
cooling
water
to
suitable
tem

perature
by
running
at

1
200

rpm
with

the
selector
lever
in

the

range
P
for

several
minutes
Warm

up
the

torque

converter
oil
to
suitable

temperature

6010
1000C
140
to

2l20F

I

Mount
the

engine
tachometer
at
a

location
that
allows

good
visibility

fro

the
dri
er
s
seat
and

put
a
mark

on

specified
revolutions
on
the
meter

2

Secure
the
front
and
rear
wheels

with
chocks
and

apply
the
hand
brake

Be
sure
to

depress
the
brake

pedal

fumly
with
the
left
foot
before
de

pressing
the
accelerator

pedal

3
Throw
the
selector
lever
into

the

range
1

4

Slowly
depress
the
accelerator

pedal
until
the

throttle
valvc
is

fully

opened

Quickly
read
and
record
the

engine
revolution
when

the

engine

begins
to
rotate

steadily
and
then

release
the
accelerator

pedal

5

Shift
the
selector
lever
to
N

and

operate
the

engine
at

approxi

mately
1
200

rpm
for
more
than
one

minute

to
cool
down
the

torque
con

ver
ter
oil

and
coolant

6

Make
similar
stall
tests
in

ranges

2
I
and
RIO

Note
The
stall
test

operation
as

speci

f
d
in
item
4

should
be

I
l3de

wiihin
five
seconds
If
it

takes
too

long
the
oil
deteriorates
an

the

clutches
brake

and
band
are
ad

versely
affected
Sufficient
cooling

time
should
be

given
between
each

AT
5O
test
for
the
four

ranges
0
2

I
and
R

JUDGEMENT

High
stall
revolution
more

than

standard
revolution

If
the

engine
revolution
in
stall

condition
is

higher
than
the
standard

values
it

indicates
that
one

or
more

clutches
in

the
transmission
are

slipping
and
therefore
no
further
test

is

required

For
the

following
abnormalities

the

respective
causes
are

presumed

High

rpm
in

all

ranges
low
Iine

pressure

High
rpm
in
D
2
and
I

and

normal

rpm
in
R
Rear
clutch

slipping

High
rpm
in
0

and

normal

rpm
in
I

clutch

slipping

High
rpm
in
R

only
Front

clutch
or
low
and
reverse

brake

slipping

To

determine
which
is

slipping

front
clutch
or
low

and
reverse
brake

a
road
test
is
nceded

If
whilc

coasting
after

starting

with
the
lever
in
1

range
engine

braking
does

not
work

properly
the

low
and

reverse
brake
is

slipping

Otherwise
the
front
clutch
is

slipping

Slipping
of
the
band
brake
is

diffi

cult
to
ascertain

However
if
it

occurs

with
the
lever
in
2

range

engine

revolution
increases

Jp
to
thesarne

level
as
in

I

strange
It

is

impossible

to
check

it
in
the
stall
test
2
and

One

way

2
Standard
stall
revolution

If
the

engine
revolution
in

stall

condition
is
within

the
standard

values
the
control
elements
are

nor

mally

operating
in
the

ranges
0

2
I

and
R

Also

tIle

engine
and
one

way

clutch
of
the

torque
converter
are

normal
in

performance
and

operation

The
one

way
clutch
of

the

torque

converter
however
sometimes

sticks

This
is
determined
in

the
road
test

3
Lower
stall
revolution
than
stand

ard
revolution

If
the

engine
revolution
in
stall

condition
is

lower
than
the
standard