1977 DATSUN PICK-UP stop start

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

Note
Vacuum
hose

position
R
R

side
of
Nissan
mark
on
the

top
of

sensor
for

intake
manifold
L
R

side
of
the

mark
is
for
vacuum

rootor

2
2

Vacuum
motor

I
With

engine
stopped
disconnect

fresh
air
duct

Place
a
mirror
at
the

end
of
air

cleaner
inlet

pipe
as
shown
and
check

to
see
if
air

control
valve
is
in

correct

position

EF213

Fig
ET
27

Impecting
lJalv

position

Air
control
valve
is
in
correct

posi

tion
if
its
under
hood
air
inlet
is

open

and
hot
air
inlet
is

closed
Check
air

control
valve

linkage
for
condition

2

Disconnect
vacuum
motor
inlet

vacuum
hose
and
connect
another

hose
to

the
inlet
to

apply
vacuum
to

vacuum
motor
Vacuum
can
be

ap

plied
by
breathing
in

the
hose
end
as

shown

Place
a
mirror
at
the
end
of
air

cleaner
inlet

pipe
and
check
to
see
if

air
control
valve
is
in
correct

position
Engine
Tune

up

EF217

Fig
ET
28

lmpecting
value

position

Correct

pC6ition
of
air

control
valve

is
the

reverse
of

paragraph
I
above
Air

control
valve
is
in
correct

position
if

under
hood
air
inlet
is
closed
and
hot

air

inlet
is

open

3
With
hot
air
inlet
is

open
posi

tion
as
descnbed
in

paragraph
2

above

pinch
vacuum
hose
with

fingers

and
cut
of
air
from
vacuum
hose

In

this
condition
check
that
air

control

valve
maintains
the
condition
de

scribed
in

step
2

for

more
than
30

seconds
and

that
hot
air
inlet
is

open

If

diaphragm
spring
actuates
the

air

control
valve

by
its

spring
force

to

open
under
hood
air

inlet
within
30

seconds

replace
vacuum
motor
as
an

assembly
since
this

may
be
resulted

from
air

leak
at

vacuum
motor
dia

phragm

2
3

Temperature
sensor

Check

temperature
sensor
for
func

tion

by
proceeding
as
follows
Be

sure

to

keep
engine
cold
before

starting

test

1
With

engine
off
check
air

control

valve
for
condition
In
this
case
under

hood
air

inlet
is

open
Use
a
mirror
for

inspection
as
2
2
1

above

2
Start

engine
and

keep
idling

Immediately
after

engine
starting

check
air

control
valve
for
correct

position
as
described
above
In
this

case
correct

position
of
air
control

valve
is
the
reverse
of
2
2
1
under

hood
air

inlet
is

closed
and
hot
air

inlet
is

open

ET

16
3

Check
that
air
control
valve

grad

ually

opens
to
under
hood
air
inlet

side
as

engine
warms

up
When
en

vironmental

temperature
around
tern

perature
sensor
is
low

spend
more

time

for

engine
warming
up
operation

to

facilitate
smooth

opera
tion
of
air

con
trol
valve

If
the
above

test
reveals

any
prob

lem
in
the

operation
of
air
control

valve

carry
out
the

following
test

4

Remove
air
cleaner
cover
Set

temperature
sensing
element

of
ther

mistor
or
thermometer
to

a
position

where

tempera
ture
around
sensor
can

be
measured
In
this
case
fix

wiring
of

thermistor
or
thermometer
on
the
bot

tom
surface
of
air

cleaner
with
adhe

sive

tape
in

such
a
manner
that

the
set

position
of

temperature
sensing
ele

ment
will
not

be
affected

by
airflow

Then
install
air
cleaner
cover

EF221

Fig
ET
29
Checking
temperotur
e

ensor

5

Carry
out
test
as
described
in

steps
I
2

and
3
above
When
air

control
valve

begins
to

open
to
under

hood
air
inlet
side
severa
minutes

after

engine

starting
read
the
indica

tion
of
thermistor
or

thermometer
If

reading
falls
within
the

working
tern

perature
range
of

temperature
sensor

the
sensor
is

normaL
If

reading
ex

ceeds
the

range

replace
the
sensor

with
new
one

Note
Before

replacing
temperature

sensor
check
idle

compensator
as

described
in
Section
EF

page
EF
8

Ignition
Switch
Position
START

Detector
Drive
Counter

E

G
R

Warning
Lamp
ON

a
After

completing
inspection
of

E
G
R
control

system
be
sure
to

reset
odometer
of
detector
drive

counter
to
zero

b
This
item

applies
to
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
movirig
dia

phragm
of
control
valve

upwards
with

fmgers
Engine
Tune

up

ON

Below

50

000
counts
Above

50
000
counts

OFF
ON

4
With

engine
running
inspect

E
G
R
control
valve
and
thermal

vacu

um
valve
for

normal

operation

I
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

fingers
on
the

diaphragm
of

E
G

R
control
valve
to
check
for
valve

operation

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

fingers
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
ofvacuum
hose
connect

ing
thermal
vacuum
valve
to

E
G
R
EC253

Fig
ET
40

Checking
E
G
R
control
valve

control
valve

Increase

engine
speed
from

idling
to

3

000
to
3
500

rpm

Make
sure

that
thermal
vacuum

valve
is

open
and
that
carburetor

vacuum
is

present
at
the
end

E
G
R
control
valve

side
ofvacu

urn
hose

If
vacuum
is
weak
or
not

present
at

all

replace
thermal
vacuum
valve
If

vacuum
is

present
replace
E

G
R

con
trol
valve

ET
21
EC254

Fig
ET
41

Checking
thermal

vacuum

valw

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

0

r11

hC

J

ET152

Fig
ET
42

Checking
E
G
R
control

VGlve

2

Visually
check
E
G
R
control

valve
for

damage
wrinkle
or
deforma

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

r

AIR
CLEANER

1
Loosen

bolts

securing
air
cleaner

to
air
cleaner
bracket

2
Loosen
air

cleaner
lock
bolt
and

remove
air

cleaner
from
carburetor

Disconnect
the

following
hoses
when

dismounting
air

cleaner

Under
hood
air
inlet

hose

Hot
air
inlet

hose

Vacuum

hose
Sensor
to
intake

manifold

Vacuum
hose
Sensor
to
vacuum

motor

Vacuum
hose

Idle

compensator
to

intake
manifold

Hose
Air

pump
to
air
cleaner

Hose
AB
valve

to
air
cleaner

Hose
Carburetor
to
air

cleaner

Blow

by
hose
Air

cleaner
to

rocker

cover

Hose
Air

control
vaive
to
air

cleaner
California

models

only

3
To

install

reverse
the
removal

procedure

INSPECTION

1
AIR
CLEANER

ELEMENT

Viscous

paper
type
air
cleaner

ele

ment
does
not

require
any
cleaning

operation
until
it

is

replaced
periodi

cally
Brushing
or

blasting

operation

will
cause

clogging
and

result
in
enrich

ment

of
carburetor
mixture

and

should
never
be

conducted
For

reo

placement
interval
of
air

cleaner
ele

ment
refer
to
Maintenance
Sched

ule

2
HOT

AIR

CONTROL
SYSTEM

In

warm
weather
it
is

difficult
to

find

out
malfunction
of
hot
air
control

system
In

cold
wea
thee

however

malfunction
of
air
control
valve

due
to

disconnection
or

deterioration
of

vacu

um

hose
between
intake
manifold
and

vacuum
motor
and

insufficient
dura

bility
of
air
control
valve

will
cause

insufficient
automatic
control

opera

tion

for
intake
air
and

result
in

engine

disorder

including

I

Stall

or
hesitation
of

engine

oper

ation

2

Increase
in

fuel

consumption

3

uck
of

power
Engine
Fuel

These

phenomena
reveal
malfunc

tion
of
hot
air
control

system
If
these

phenomena
should
occur
check
hot

air
control

system
as

described
in
the

following
before

carrying
out

inspec

tion

of
carburetor

2
1
Vacuum

hose

Intake
manifold
to
3

way
connec

tor
3

way
connector
to

temperature

sensor
3

way
connector
to

idle
com

pensator
temperature
sensor
to
vacu

um

motor

I

Check
that

vacuum
hoses
are

se

curely
connected
in

correct

postion

2

Check
each
hose
for

cracks
or

distortion

hose

clip
for

condition

Note

Vacuum
hose

position
R
H

side
of
Nissan

mark
on
the

top
of

sensor
is
for

intake
manifold
L
U

side
of

the
mark

is
for

vacuum

motor

2
2
Vacuum

motor

I

With

engine
stopped
disconnect

fresh
air

duct

Place
a
mirror

at
the
end
of
air

cleaner
inlet

pipe
as
shown
and

check

to

see
if
air

con
trol
valve

is
in

correct

position

EF213

Fig
EF
11

Inspecting
valve

position

Air

control
valve
is
in

correct

posi

tion
if
its
under
hood
air

inlet
is

open

and
hot
air
inlet
is

closed
Check
air

control
valve

linkage
for

condition

2

Disconnect

vacuum
motor
inlet

vacuum
hose
and
connect

another

hose
to
the
inlet
to

apply
vacuum
to

vacuum
motor
Vacuum
can
be

ap

plied
by
breathing
in
the

hose
end

as

shown

Place
a
mirror

at
the

end
of
air

cleaner
inlet

pipe
and

check
to

see
if

air

control
valve

is
in
correct

position

EF
6
EF217

Fig
EF
12

Inspecting
valve

position

Correct

position
of
air

control
valve

is

the
reverse
of

paragraph
J
above
Air

control
valve
is
in
correct

position
if

under
hood
air
inlet
is

closed
and
hot

air

inlet
is

open

3
With

hot
air

inlet
in

open
posi

tion

as
described
in

paragraph
2

above

pinch
vacuum
hose
with

fingers

and
cut
off
air

from
vacuum
hose
In

this
condition
check
that
air

control

valve

maintains
the

condition
de

scribed
in

step
2

for
more
than
30

seconds
and
that
hot
air

inlet
is

open

If

diaphragm
spring
actuates
the
air

control
valve

by
its

spring
force
to

open
under
hood
air
inlet

within
30

seconds

replace
vacuum
motor
as
an

assembly
since
this

may
be

resulted

from

air
leak
at
vacuum
motor
dia

phragm

2
3
Temperature
ensor

Check

temperature
sensor
for
func

tion

by

proceeding
as
follows
Be

sure

to

keep
engine
cold
before

starting

test

I

With

engine
off

check
air

control

valve
for
condition
In

this
case
under

hood
air

inlet
is

open
Use
a
mirror

for

inspection
as
2
2
1

above

2

Start

engine
and

keep
idling

Immediately
after

engine
starting

check
air
control
valve
for

correct

position
as
described
above
In

this

case
correct

position
of

air
control

valve

is
the
reverse
of
2
2
I

under

hood
air

inlet
is

closed
and
hot

air

inlet
is

open

3
Check
that
air
control
valve

grad

ually
opens
to
under
hood
air

inlet

side
as

engine
warms

up
When
en

vironmental

temperature
around
tern

perature
sensor
is

low

spend
more

time

for

engine
warming
up
operation

854
co
in
in
one
minute
or
less

If
no

gasoline
or

only
a

little
flows

from

open
end
of

pipe
with

pump

operated
or
if

pump
does

not
work

perform
the

following
diagnosis

Notes

3
Do
not

connect
battery
in
reverse

polarity
which
if
left
for
a

long

time
would

damage
transitor

circuit
and
disable

pump
Engine
Fuel

b
Do
not
let
fall

pump
as
it

may

damage
electronic

components

c
Do
not

apply
overvoitage
max

l
8Y

Overvoltage
starting

by

quick
charge
or

tage
running

would
deteriorate
or

damage
elec

tronic

components

Fuel

pressure
maximum

0
32

kg
cm
4
6

psi

REMOVAL
AND
INSTALLATION

Flom
fuel
tank

Electric
fuel

pump
is
installed
on

bracket
with
two
bolts
This
bracket
is

located
on
R
H
side
member

adjacent

to
fuel
tank

I
Remove
inlet
hose
from
fuel

pump
Also
remove
outlet
hose
run

ning
to

engine
Receive
fuel

remaining

in
fuel
hose
in
a
suitable
container

2
Disconnect
harness
at

connector

3
Remove
bolts

securing
fuel

pump

to
bracket
and
detach
fuel

pump

4

Installation
is

the
reverse
order
of

removal

9

@

1
Cover

2

Magnet

3
Cover

gasket

4
Filter

5
Gasket

6

Spring
retainer

7
Washer
8
O

ring

9
Inlet
valve

10
Retutn

PIing

11
Plunger

12

Plunger
cylinder

13

Body
To
carburetor

1
Elecuic
fuel

pump

2

Mounting
bracket

3
Fuel
mter

EF72D

Fig
EF
23
Electric
fuel

pump

DISASSEMBLY

Do
not
disassemble
unless

pump
is

faulty

I
Remove

cover
with
wrench
and

take
out
cover
gasket
magnet
and

filter
from

pump
body

2
When

removing
plunger
take
out

spring
retainer
from

plunger
tube

3
Then
take
out
washer
O

ring

inlet
valve
return

spring
and

plunger

from
tube

Note
Do
not
disassemble
electronic

components
If

n

replace

with
new
ones

6

EF721

Fig
EF
24

Exploded
view

of
electric
fuel

pump

EF
12
ASSEMBLY

I

Before

assembly
clean
all

parts

with

gasoline
and

compressed
air

com

pletely

Notes

a
If

gask
t

an
d
fdterare

faulty
r

place

b
Clean

magnet
and
cover
for
fault

c
Take
care
not
to
defonn
thin
tube

d
Assemble

plunger
return

spring

inlet
valve
O

ring
washer
and
set

spring
retainer
in
that
order

e

Assemble
filter

gasket
and
cover

with

f

Tighten
cover
with
wrench
to
the

stopper

If

component
parts
are

dirty
after

disassembly
clean
as
follows

Wash
fIlter
and
strainer
with
clean

gasoline
and
blow
with

compressed

air
When

cleaning
parts
check

fllter
for
fault
If

faulty
replace

Wash

plunger
plunger
cylinder
and

inlet
valve
with
clean

gasoline
and

blow
dust
off

with

compressed
air

2
Check

c
v
m
lI

parts
for
wear

or

damage

If

they
are
found

faulty

replace

them

3

Insert

plunger
assembly
into

plunger
cylinder
of

body
and

apply

electric
current
to
it

Move
the

assembly

up
and
down

If
the

assembly
does
not
move
it

shows

that
the
electric

uuit
is

faulty

and
it
must
be

replaced

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

When
throttle
valve
is

opened
fur

ther

locking
arm
is
detached
from

secondary
throttle
arm

permitting
see

ondary

system
to

start

operation

Linkage
between

primary
and

see

ondary
throttles
will
function

properly

if
distance

between
throttle
valve
and

inner
wall

of
throttle

chamber
is
74

mm

0
291
in

Adjustment
is
made

by
bending

connecting
link

I

L
l

1

4
CAl

Secondary
prm

ary
I

Jl
I

7
t
@

1
Roller

4

Adjust
plate

2

Connecting
lever

5
Throttle
c
amber

3
Return

plate
6
Throttle
valve

Fig
EF

48

Adjusting
interlock

opening

DASH
POT

1

Idling
speed
of

engine
and
mix

ture
must
be

well
tuned

up
and

engine
sufficiently
warm

2

Turn
throttle
valve

by
hand
and

read

engine
speed
when

dash

pot

just

touches

stopper
lever

3

Adjust
position
of

dash

pot
by

turning
nut

until

engine
speed
is
in
the

specified
range

Specified
engine

speed

Manual
transmission

1

900
to
2

100

rpm

Automatic
transmission

1
650
to
1

850

rpm

4

Tighten
lock

nuts

5
Make

sure
that

engine
speed

drops
smoothly
from
2

000
to
1

000

rpm
in

about
three

seconds
Engine
Fuel

Fig
EF
49

Adjusting
dash

pot

ACCELERATING
PUMP

I

Visually
inspect
accelerating

pump
cover
for

any
sign
of
fuel
leaks

2
If

fuel
leaks
are
found
check

gasket
and

replace
if

necessary

ANTI

DIESELING

SOLENOID
VALVE

If

engine
does
not

stop
when

igni

tion
switch
is
turned
off

this
indicates

that
a

striking
closed
solenoid

valve

is

shutting
off

supply
of
fuel
to

engine

If
harness
is
in

good
condition

replace
solencid
valve
as
a
unit

Notes

a

Tightening
torque
is
1

8
to
3
5

kg
m
13
to
25

ft
Ib

b

After

replacement
star

engine
and

check
to
be
sure
that
fuel
is
not

leaking
and
that
anti
dieseling

sol

noid
is
in

good
condition
B
C
D
D

CIRCUIT
WITH

FUNCTION
TEST

CONNECTOR

Caution
Do

not
attach
test
leads

of
a

circuit

tester
to
those
other

than

designated
Refer
to

Figure
EF

50

Menuel

trensmlsslon
models

I

Check
for

continuity
between
A

and
B
when

vehicle
is

brought
to
a

complete
stop
Refer
to

Figure
EF

50

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
A

and
B
at

a

speed
of
more

than
16

km
h

10
MPH
Refer
to

Figure
EF

50

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

1

P4
11
0

8

l
1

Ignition
Icey

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
EF

50

Checking
B
C
D
D
circuit
with

function
test

connector

for
manual
transmission

EF
25

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