1977 DATSUN PICK-UP wiring

Yellow

line

Spark
delay
valve
to

distributor

Spark
delay
valve
to
vacuum
tube

Distributor

to
vacuum
tube

Vacuum
tube
to
carburetor

Vacuum
tube
to
canister

Green
line

Anti

backfire
valve
to
intake
mani

fold

Air

control
valve
to

emergency
air

relief
valve

Intake
manifold
to
vacuum
hose

connector

Intake

manifold
to
canister

CHECKING
ENGINE

COMPRESSION

COMPRESSION
PRESSURE

TEST

I
Warm

up
engine
sufficiently

2
Disconnect

all

spark
plugs

3
Disconnect
anti

dieseling
solenoid

valve
connector

4

Properly
attach
a

compression

tester
to

spark

plug
hole
in

cylinder

being
tested
Engine
Tune

up

I

ET010
Different

compression
in
two
or

more

cylinders
usually
indicates

an

improperly
seated
valve
or
broken

piston
ring

9
Low

compression
in

cylinders
can

result
from
worn

piston
rings
This

condition

may
usually
be

accompanied

by
excessive

fuel

consumption

TEST
RESULT

If

compression
in

one
or
more

cylinders
is
low

pour
a
small

quantity

of

engine
oil
into

cylinders
through

the

spark
plug
holes
and
retest
com

pression

I

If

adding
oil
increases
the
com

pression
pressure
the
chances
are
that

rings
are

faulty

2

If

pressure
stays
low

probable

cause
is

that
valve
is

sticking
or

seating

improperly

3
If

cylinder
compression
in

any

two

adjacent
cylinders
is

low
and
if

adding
oil
does
not

help
the

compres

sian
there
is

leakage
past
the

gasket

surface

Oil
and
water
in

combustion
cham

bers

can
result
from

leakage

IGNITION
AND

FUEL
SYSTEM
Fig
ET
10

Teding

compression

pressure

5

Depress
accelerator

pedal
to

open

throttle
and
choke
valves

Note
Do

not

pump
pedal

6
Start

engine
as

quickly
as

pos

sible

7

Compression
pressure

kg
cm2

psi
at

rpm

Standard

12
0

171
350

Minimum

9

0
128
350

8

Cylinder
compression
in

cylinders

Should
not
be
less
than

80
of

highest

reading

CONTENTS

CHECKING
BATTERY
ET
9

CHECKING
DISTRIBUTOR
CAP
ROTOR

CHECKING
AND

ADJUSTING
IGNITION
AND
CONDENSER
ET
11

TIMING
ET
10

CONDENSER
ET
11

ADJUSTING
IGNITION
TIMING
ET10

ADJUSTING
CARBURETOR
IDLE
RPM

CHECKING
AND
REPLACING
SPARK
PLUG
ETlO
AND
MIXTURE
RATIO
ET

11

CHECKING
DISTRIBUTOR
OPERATING
IDLE

LIMITER
CAP
ET
12

PARTS
AND

IGNITION
WIRING
ETlO
CHECKING
CARBURETOR
RETURN
SPRING
ET

12

BREAKER
POINTS

lNon
California
models

ET
10
CHECKING
CHOKE
MECHANISM

AI
R

GAP
lCalifornia
models
ET11
Choke

plate
and

linkage
ET13

DISTRIBUTOR
ET
11
CHECKING
FUEL

LINES

IGNITION
WIRING

ET
11
Hoses

pipings
connections
etc

ET
13

REPLACING
FUEL
FILTER
ET
13

CHECKING
BATTERY

Check

electrolyte
level
in

each
bat

tery
cell
I
Unscrew

each
filler

cap
and

inspect
fluid
level
If
the
fluid
is
low

add
distilled
water
to

bring
the
level

up
approximately
10
to
20
mm
0
39

H
9
to
0
79

in
above
the

plates
Do
not

overfill

2
Measure
the

specific
gravity
of

battery
electrolyte

p

r

ET002

Fig
E1
11

Checking
specific
gravity

of
bottery
electrolyre

Clean

top
of

battery
and
terminals

with
a
solution
of
bakin

soda
and

Pennissible

value

Frigid
climates
Over
1

22

Tropical
climates

lOver
1
18

Other
climates

lOver
1
20

CHECKING
AND

ADJUSTING

IGN

ITIONTIM
iNG

AD
IUSTING
IGNITION

TIMING

I
Check

spark
plugs
and
distributor

breaker

points
for
condition

2

Thoroughly
remove
dirt
and
dust

from

timing
mark
on
crank

pulley
and

timing
indicator
on
front
cover

3
Warin

up
engine
sufficiently

4
Imtalla
timing
light
on
No
I

cylinder
spark
plug
wire
and
install
a

tachometer

5
Set

idling
spero
toapproxintate
y

750

rpm

6
Check

ignition
timing
with
a

timing
light
if
it
is

specified
value

If

necessary

adjust
it

as
follows

1
Loosen
setscrew
until
distribu

tor

can
be
moved

by
hand

2

Adjust
ignition

timing
to

speci

fied
value

3
0
Lock
distributor
setscrew

ai1d

make

sure
that

timing
is
correc
Engine
Tune

up

water

Rinse
off
and

dry
with
com

pressed
air

Top
of

battery
must
be

clean
to

prevent
current

leakage
be

tween
terminals
and
from

positive

terminal

to
hold
down

clamp

In
addition
to
current

leakage
pro

longed
accumulation
of
acid

and
dirt

o
n

top
If
l

l
ry
may

ca
u
iCbli
t

rj
I
g

of
the
material

covering
connector

straps
and
corrosion
of

straps
After

tightening
terminals
coat
them
with

petrolatum
vaseline
to

protect
them

from
corrosion

Full

charge

value

at
200C
680F

1
28

1
23

1
26

oo

I

ET169

Fig
ET

13

Checking
ignition
timing

Ignition

timing

Manual
transmission

120
750

rpm

Non
California
models

100
750

rpIll

California
models

Automatic
transmission

120

650

rpin

in

0

position

ET
10
CHECKING

ANb

REPLACING

SPARK

PLUG

I

Remove

and
clean

plugs
in

a
sand

blast
cleaner

2

Inspect
insulator
for
cracks
or

chips

3

Check
both
center
and

ground

electrodes

If

they
are

excessively
worn
re

place
with
new

spark

plugs

4

Spark
plug
gap

Breaker

points

type

0

8
to
0
9

mm

0
031
to
0
035
in

Transistor

ignition

type

1
0

to
1
1

mm

0
039
to
0
043
in

Tightening

torq

1
5
to
2
0

kg
m

11
to
A4
ft
lb

Fig
ET
14

Checking

spark
plug
point

gap

CHECK
I
G

DISTRIBUTOR

OPERATING

PARTS

AND

1

lrI9N

WIRING

BREAKER

POINTS

Non

California
models

Check
the
distributor
breaker

points
for
abnonnal

pitting
and
wear

Replace
if

necessary
Make
sure

they

are

properly

aligned
and
that

point

dwell

and

gap
are
correct
Clean
and

apply
distributor

grease
to
the
carn

lobes

Note
00

not

apply
grease
excessively

Point

gap

0

45
to
0
55
mm

Om8
to
0
022

in

Owell

angle

49
to
55

degrees

EE322

Fig
ET
15
Checking
diltribu
tor

point

gap

AIR
GAP

California
models

For

inspection
procedures
and

reference
data
refer

to
the

topic
Air

Gap
in

Section
EE

page
EE
29

DISTRIBUTOR

Check

centrifugal
advance
unit
for

loose
connection
or

improper
opera

tion
If
it
is
not

operating
properly

the

problem
may
be

due
to
a

sticky

spring
or
excessively
worn

parts
This

operation
needs
a
distributor
tester

For

inspection
procedures
and

ref

erence
data
refer
to

relative

topic

under
Distributor
in

Section
EE

If
vacuum
advance
mechanism
does

not

properly
operate
check
for
the

following
items
and

correct
the

prob

lem

as

required

1
Check
vacuum
inlet
for

signs
of

leakage
at
connection
If

necessary

retighten
or

replace

2

Check
vacuum
diaphragm
for
air

leak

If

necessary
replace
diaphragm

3

Inspect
breaker

plate
for
smooth

movement

If

plate
does
not
move
smoothly

this
condition
could
be
due

to

sticky

steel
balls
If

necessary
replace
break

er
plate
assembly

IGNITION
WIRING

Use

an
ohmmeter
to
check
resist

ance
of

secondary
cables
Disconnect

cables
from

spark

plugs
and
install
a

proper
adapter
between
cable
and

spark
plug
Remove

distributor
cap

and
secondary
cables
as
an

assembly

Do
not
remove
cables
from

cap

Check
resistance
of
one
cable
at
a

time

Connect
ohmmeter
between

spark

plug
adapter
and

corresponding
elec

trade
inside
cap
If
resistance
is
more

than
30
000
ohms
remove
cable
from
Engine
Tune

up

cap
and
check
cable
resistance

only
If

resistance
is
still
more
than

30
000

ohms

replace
cable

assembly

EF125

Checking
high
tension

cable

CHECKING

DISTRIBUTOR
CAP

ROTOR
AND

CONDENSER

Note
This

operation
is

to
be

per

formed
while

checking
distributor

points
Inspect
distributor

cap
for

cracks
and

flashover

External
surfaces
of
all

parts
of

secondary
system
must
be
cleaned
to

reduce

possibility
of

voltage
loss
All

wires
should
be
removed
from
distrib

utor

cap
and
coil
so
that
terminals

can

be

inspected
and
cleaned
Burned
or

corroded
terminals
indicate
that
wires

are
not

fully
seated
which

causes

arcing
between
end
of
wire
and
ter

minal
When

replacing
wires
in

ter

minai
be

sure
they
are

fully
seated

before

pushing
rubber

nipple
down

over
tower
Check
distributor
rotor
for

damage
and
distributor
cap
for

cracks

CONDENSER

I
Clean

outlet
of
condenser
lead

wire

and
check
for

loose
setscrew

Retighten
if

necessary

2
Check

condenser
with
a
con

denser
tester

Condenser

capacity

0
20
to
0
24

IF

Micro
Farad

Condenser
insulation
resistance

5Mn

Mega
ohms

ADJUSTING

CARBURETOR
IDLE

RPM
AND
MIXTURE

RATIO

Cautions

a
On
automatic
transmission

equip

T
11
ped
models
check
should
be

per

fonned
in

the
D

position

Be
sure

to

engage
parking
brake
and

to
lock
both
front
and
rear

wheels

with
wheel
chocks

b

Keep
your
foot
down
on
the
brake

pedal
while

depressing
the
accelera

tor

pedal
Otherwise
vehicle

surges

forward

dangerously

Notes

a
Do
not

attempt
to
screw
the
idle

adjusting
sc
ew
down

completely

Doing
so
could
cause

damage
to

tip

which
in

turn
will
tend
to
cause

malfunctions

b

If
idle
limiter

cap
obstructs

proper

adjustment
remove
it

To
install
idle
limiter

cap
refer
to

Idle
Limiter

Cap

c

After
idle

adjustment
has

been

made
shift
the
lever
to
the
N
or

P

position
for
automatic
trans

mission

d
When

measuring
CO

percentage
in

sert

probe
into

tail

pipe
more
than

40
em
15
7
in

CO
idle

adjustment
with

CD
meter

Idle
mixture

adjustment
requires

the
use
of
a

CO
meter

especially
for

California
models
When

preparing
to

adjust
idle
mixture
it
is

essential
to

have
the
meter

thoroughly
warmed

up

and
calibrated

I
Check
carburetor

pipes
for

proper

connection

2

Warm

up
engine
until
water
tem

perature
indicator

points
to
the
middle

of

gauge
The

procedure
to
warm

up

engine
is
not

specifically
recom

mended
Either

driving
vehicle
or

oper

ating
engine
at

no
load
will
be

good

3
Make

sure
that
water
tempera

ture
indicator

points
to

the
middle

Further

keep
engine
running
at
about

2

000

rpm
for
about
5
minutes
with

out

applying
load
to

engine
in

order
to

stabilize

engine
condition
Engine

hood
should
be

open

4
Run

engine
for

about
10
minutes

at
idling
speed
During
this
10

minutes

proceeq
as
described
i

steps

5

to
9
below

5
Remove
air
hose
between
3

way

connector
5

way
connector
for
Cali

fornia
models
and
air

check
valve
as

shown
in

Figure
ET
17

Plug
the

dis

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

Replace
bulb
if

bulb
is
burned

ou
t

If

bulb
is
not
burned
trace

wireis

back

to

ignition
switch

Repair
or

replace
if

necessary

2

Be
sure
that

floor

temperature
is

cool

below
800C

1760F
before

carrying
out
the

following
procedure

1
Remove
rear
seat

2

Ignition
switch
is
turned
to

the

Temperature

sensing
switch
Temperature

warning
lamp

Contact
close
Off

Contact

open
On

Note

Avoid

heating
floor

tempera

ture

sensing
switch
directly

If

lamp
does

not

glow
check
floor

temperature
sensing
switch
connector

for

continuity
with
a
circuit

tester

If

continuity
should
exist

after

heated

surrounding
areas
of
floor
tern

rv
wnTP
sen
cinq
S
Vitch

reolace
tem

perature
sensing
switch

If

continuity
does
not
exist

trace

the

wiring
back
to

relay
or
check
the

following
step
3

Repair
or

replace

wire

s
if

necessary

Note
The
floor

temperature
sensing

switch

may
be
heated

through
the

floor

by
a

proper
heater

3
Turn

ignition
switch
to
the
IG

position
anf
disconnect
floor

temper

ature

sensing
connector
The

lamp

should
remain

on
If
not

check
floor

4
0
3

UJ

GJO
Engine
Tune

up

IGU

position

3
Ensure

that
floor
tem

perature

warning

lamp
goes
out

4

Heat

surrounding
areas
of
floor

temperature
sensing
switch
with
a

proper
heater

to
ensure
that
floor

temperature
warning

lamp
glows
when

floor
is

heated
to

lh

specifications
as

shown

in
the
table
below

Floor

temperature

Below

1050C

22IOF

Above
1050C

2210F

temperature
relay
for

continuity
with

a

circuit
tester

Referring
to
the

following
floor

temperature
relay
if

relay
is
normal

trace

wire
s
back
to

ignition
switch

Repair

faulty
wiring

Floor

temperature

rela

To

check
floor

temperature
relay

remove
it

and

proceed
as

follows

1
Check
for

continuity

between@

and

@
Continuity
should

exist

Check
for

continuity
between

D

and@
Continuity
should
exist

Check
for

continuity
between

D

and@
Continuity
should
not
exist

2

Apply
a
12
volt
doC

across@and

@
to

ensure
that

continuity
exists

between

D
and@and
that

continuity

does
not
between

D
and

@
If
test

r
I

141

ET
24
results
do
not

satisfy
the
above
reo

place
the
floor

temperature
relay

When
floor

temperature

warnln8
lamp
118hts

Check
floor

temperature
warning

lamp

I

Open
or

short
circuit
in

wiring

harness

2

Check
fuel

system
with

regard
to

the

following
items
Refer
to

Inspec

tion

of
Fuel

System

I
Floa

t
level

2

Choke

3

Normal

fuel

supply
system
Prima

ry
and

secondary

4

Accelerator

pump

5

Power
valve

6

B
C
D
D

7

Fuel
strainer

8
Air

cleaner

3
Check

ignition
system
with

regard

to

the

following
items
Refer

to

Inspection
of

Ignition
System

I

IgnItion
AMI

2

Distributor

3

Ignition
coil

4

High
tension

code

5

Spark

plug

4

Check

idle
CO

adjustment
Refer

to

Inspection
of
Idle

CO

Adjust

roeoC

Note
Even

if
there
is

nothing
wrong

with

engine

warning
lamp
may

come
on
if
vehicle
is

being
driven

on
a

steep
slope
continuously
in

lower

gears
at

high
engine

speeds

To
floor

temperature

warning
lamp

2
From
S

position

3
From
GOt

position

4

From

ignition
switch

5
To
floor

temperature

sensing
switch

EC343

Fig
ET
50

Checking
floor

temperature

relay

Engine
Tune

up

TROUBLE
DIAGNOSES
AND

CORRECTIONS

Condition
Probable
cause

CANNOT
CRANK

ENGINE
OR

SLOW

CRANKING
Improper
grade
oil

Discharged
battery

Faulty
battery

Loose

fan
belt

Malfunction
in

charge
system

Wiring
connection
loose
in

starting
circuit

Faulty
ignition
switch

Faulty
starler
motor

Trouble

shooting
procedure
on

starting
circuit

Switch
on
the

starting
motor
with

light
ON

When

light
goes
off
or
dims

considerably

a
Check

battery

b
Check
connection
and

cable

c
Check
starter
motor

When

light
stays
bright
Corrective
action

Replace
with

proper
grade
oiL

Charge

battery

Replace

Adjust

Inspect

Correct

Repair
or

replace

Repair
or

replace

a
Check

wiring
connection
between

battery
and
starter

motor

b
Check

ignition
switch

c
Check
starter
motor

ENGINE
WILL
CRANK

NORMALLY
BUT

WILL
NOT

START

In
this
case
the

following
trouble
causes

may
exist

but
in

many
cases

ignition

system
or
fuel

system
is
in

trouble

Ignition

system
in
trouble

Fuel

system
in
troubk

Valve
mechanism
does
not
work

properly

Low

compussion

Trouble

shooting
procedure

Check

spark
plug
firstly
by

following
procedure

Disconnect

high
tension
cable
from
one

spark
plug
and
hold
it

about
10
mm
0
39
in

from
the

engine
metal

part
and
crank

the

engine

Good

spark
occurs

Check

spark
plug

b
Check

ignition
timing

c
Check
fuel

system

d
Check

cylinder
compression

Check
the
current
f10
in

primary
circuit

Very
high
current

Inspect
primary
circuit
for
short

Check
breaker

poiIit
operation

except
tran

sistor

ignition
system
No

spark
occurs

ET

27

to

facilitate
smooth

operation
of
air

control
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

temperature
around
sensor
can

be

measured
In

this
case
fIx

wiring
of

thermistor
or

thermometer
on
the

bottom

surface
of
air

cleaner
with

adhesive

tape
in

such
a
manner
that

the

set

position
of

temperature
sensing

DESCRIPTION

OPERATION

DESCRIPTION

The
idle

compensator
is

basically
a

thermostatic
valve

which
functions
to

introduce
the
air

directly
from
the
air

cleaner
to
the

intake
manifold
to

compensate
for
abnormal
enrichment

of
mixture
in

high
idle

temperature

The
bi
metal

attached
to
the
idle

compensator
detects

the

temperature

of
intake
air
and

opens
or
closes
the

valve
Two

idle

compensators
having

different

temperature
characteristics

are

installed
one

opens
at
an
intake
air

temperature
of

60
to
700C
140
to

l580F

and
the
other
at
70

to
900C

158
to
1940F

OPERATION

The
construction
of
the
idle

com

pensator
is

shown
in
the

following
Engine
Fuel

element
will
not
be
affected

by
air

flow

Then
install
air
cleaner
cover

Fig
EF
13

Checking
temperature

sensor

IDLE
COMPENSATOR

CONTENTS
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
several
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

Idle

compensator

EF
7

EF
7
REMOVAL
AND
INSTALLATION

INSPECTION
EF

B

EF

8

q

EF222
1

Orifice

2
Bi
metal

3
Rubber
valve

Fig
EF

14
Structure

of
idle

compensator

Bi

metal
Intake
air

temperature

No

1
Below
600C
1400F

60
to
70
C

140
to
l580F

Above
700C

158
OF

Below
700C

1580F

70
to
900C

158
to
1940F

Above
900C
1940F
No
2

EF
7
The
idle

compensator

operates
in

response
to
the

under
hood
air

temper

ature

as
shown
below

Idle

compensator
operation

Fully
closed

Close
to

open

Fully

open

Fully
closed

Close
to

open

Fully

open

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