engine DATSUN 210 1979 Service Manual

EC924

Fig
EC

60
Checking
Air
Induction

Valve

2

Check
air
induction
valve
reed

valve
for

binding
or

damage
At
the

same
time
check
filter
for

damage
or

plugging
If

necessary
replace
Filter

should
be

replaced
periodically
in
ac

cordance
with
Maintenance
Schedule
Emission

Control

System

1
Air
induction
valve
filter

2

Air
induction
valve

EC925

Fig
EC
6I
Checking
Air
Induction

Valve
and
Filter

Anti
backfire
valve
A
B
alve

I
Warm

up
engine
thoroughly

2
Disconnect
hose
from
air
cleaner

EC
20
and

place
aflriger
near
tneoutlet

3

Run

engine
at
about
3

000

rpm

under
no
load
then

quickly
return
it

to
idling
If

you
feel
a

pull
or

suction

force

on

your
finger
the
anti
J
ackfire

valve
is

functioning

normally
If
no

suction
is
felt

replace
the
anti
backfire

valve

eC76S

Fig
EC
62

Checking
Anti
bock
ire

Valve

1l

I

I

1J

1

Diaphragm
spring

2

Diapliragm

3
Valve
shaft

4
Valve

5
ValVe

seat

6
Valve
chamber

EC231

Fig
EC
64
E
G
R
Control
Value

Thermal
vacuum
valve

2

port

type

FU
and
Canada
models

The
2

port

type
thermal
vacuum

valve
is
mounted
on
the

engine

thermostat

housing
It

detects

engine

coolant

temperature
by
means
of
a

built
in

bi
metal
and

opens
or
closes

the
vacuum

passage
in
the

thermal

vacuum
valve

When
the
vacuum

passage
is

open

the

carburetor
vacuum

signal
is

applied

to
the

diaphragm
of
the
E
G
R
con

trol

valve
to
actuate
the

taper
valve

connected
to
the

diaphragm

1

Spring

2

Bi
metal

3
O

ring

EC232

Fig
EC
65
Thermal
Vacuum
Valve

2

port
type
Emission
Control

System

Thermal
vacuum
valve

3

port
type

U
S
A
models

except

FU

model

The
3

port
type
thermal

vacuum

valve
is
located

on
the
rear

end
of
the

cylinder
head

It

defects

engine
coolant

tempera

ture

by
means
of
wax

expansion
and

opens
or
closes
the
air

passage
from

the
air

cleaner

When

the
air

passage
is
closed
the

carburetor
vacuum
signal
is

applied
to

the

diaphragm
of
the
E
G
R

control

valve
to
actuate
the

taper
valve
con

nected
to
the

diaphragm
This
valve
is

also
co
used
as
a

component
for
the

Spark
Timing
Control

System

JiI2
To
air
cleaner

From
B
P
T

valve

From
distributor

EC156A

Fig
EC
66
Thermal
Vacuum
Valve

3

port
type

B
P
T
valve

The
B
P

T
valve
monitors
exhaust

pressure
to
activate
the

diaphragm

controlling
intake

manifold
vacuum

applied
to
the
E
G
R

control
vaNe
In

other
words
the

amount
of
recirculat

ed
exhaust

gas
vari

s
with
the

position

of
the
E
G
R

valve

regulated
by
the

operating
condition
of
the

engine

EC
23
To
E

G
R

control
valve
Vacuum
nal
Curce

Air
bleed
1

Exhaust

pressure

EC310A

Fig
EC
67
B
P
T
Value

REMOVAL
AND

INSTALLATION

E
G
R
control
valve

I
Disconnect

vacuum
hose
and
re

move
nuts

securing
E
G
R

control

valve
to
E

G
R

passage
The
E

G
R

control
valve

can
then
be
taken
out

Fig
EC

68

Remouing
E
G
R

Control
Valve

CAUTION

Pay
attention

not
to

give
damage
to

packing
of
E
G
R

control
valve

2

Installation
is
in

the
reverse
se

quence
of
removal

Note
In

installing
new
E
G
R

control

valve
confirm
that

the
model

num

ber
and

identification
marks
at

the

top
of
valve
are

as
follows

E
G
R
passage
arid
taibe

I

E
G
R

tube
can
be
removed

by

loosening

securing
nuts

2

Disconnect

blow

by
gas
hose
and

remove

securing
bolts
and

nuts
E

G
R

passage
can

then
be
taken

out

3

Installation
is
in
the

reverse
se

quence
of
removal

EC158A

Fig
EC
S9

Removing
E
G
R

Passage

Note

New

gasket
should

be
used
in

installing
E

G
R

passage

Thermal
vacuum
valve

The
thermal

vacuum
valve
is

made

of

plastic

Consequently
pay
attention

not
to

give
damage
to
it

On
U
s
A

models

except
for

the

FU

model
the
3

port
type
thermal

vacuum

valve
is
located
on
the

rear

end

of
the

cylinder
head

On
Canada
and

FU
mode
the

valve
is

located
on

the
front
end
of
the

cylinder
head
Emission

Corltr
ol

System

I
Drain

engine
coolant
about
one

liter

I
US

qt
Imp
qt

2

Remove
manifold
nut

securing

heat

shield

plate

I
I

LIkat
shield

plate

EC170A

Fig
EC

70

Removing
Heat
Shield

Plate

3
Disconnect
two

vacuum
hoses

and
unscrew
the
thermal
vacuum

valve
The
valve

can
then
be
taken
out

4

Installation
is
in
the

reverse
se

quence
of
removal

Note

a

Be
sure
to

apply
sealer
to
threads
of

the
valve

prior
to

installing
new

wive

b
When

installing
new

thermal
vacu

um
wive
make

sure
it
is

black

t
J

Tightening
torque

Thermal

vacuum
valve

Less
than

2
2

kg
m
16
ft
b

Manifold
nut

1
5
to

2
0

kg
m

11

to
14
ft
b

EC
24
2

port

type

3
port

type

Fig
EC
71

Removing
Thermal

Vacuum
Valve

B
P
T
valve

I

Remove

vacuum
tube
on
the

B
P
T

valve

2

Remove

screws

securing
B
P
T

valve
to

bracket

3
Disconnect
back

pressure
tube

from

B
P
T
valve

The
B
P
T

valve
can
then
be

taken

out

EC770

Fig
EC

72

Removing
B
P

T
S

curing

Screws

4

Installation

is
in

the
reverse
se

quence
of

removal

Note
In

replacing
the
B
P
T

valve

with

new
one
h
that
the

type
number
on

new

part
is
the

same
85
that
on
former

one

INSPECTION

Entire

system

I

Make
a

thorough
vjsual
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
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

3
With

engine
running
inspect

E

G
R

control
valve
and
thermal
vacu

um
valve
for
normal

operation

1
When

engine
coolant

tempera

tun
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

finger
on
the

diaphragm
of

E
G
R

control
valve
to
check
for
valve

operation

EC773

Fig
EC
73

Checking
E
G
R
Control

2

When

engine
coolant

tempera

tureishigh
Emission
Control

System

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

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
ihermal

vacuum
valve
to

E
G
R

control
valve

Increase

engine
speed
from

idling
to

3
000
to
3

500

rpm

Make
sure
that

thermal
vacuum

valve
is

open
2

port
type
or

closed
3

port
type
and

that
car

buretor
vacuum
is

present
at
the

end
E
G
R

control
valve
side
of

vacuum
hose

If

vacuum
is

weak
or

not

present
at

all

replace
thermal

vacuum
valve
If

vacuum
is

present
check
E
G
R

control
valve
or
B
P

T
valve

If

any
difficulty
is
encountered
in

judging
the
condition
of

any
com

ponent
during
above

inspection
check

the

questionable

component
in

dependently
as
follows

U

S
A

models

Ie

EC160A

Canada
models

ET429

Fig
EC
74

Checking
Vacuum

of

E
G
R
Control
Valve

EC
25
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

5t
orr

rl

1

1

Fig
EC
75
EC129A

Checking
E
G
R
Control

Valve

2

Visually
check
E
G
R
control

wive
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

Fig
EC

76

Cleoning
E
G
R
Control

Valve

Thermal
vacuum
valve

3

port
type

Remove
thermal
vacuum
valve
from

engine
Inhale
air

from

port
ofE
G
R

system
and
check
to
be
sure
that

thermal
vacuum
valve

opens
or
closes

in

response
to
its

temperature

Thermal

vacuum
valve

dosing

temperature

Above
50

to
630
C

122
to
1450
F

CAUTION

Do
not
allow
water
to

get
inside
the

thermal
vacuum
valve

EC161A

Fig
EC
77
Ch

c

jng
Th
rmal
Vacuum

Valve

3

port
type

Thermal

vacuum

valve

2

port
type

Dismount
thermal

vacuum
valve

from

engine

Note

Before

dismounting
drain
en

gine
c
oolant
from

engine

Apply
vacuum
to
thermal

vacuum

valve
and

check
to
be
sure

that
ther

SPARK
TIMING

CONTflOL

SYSTE
VI

DESCRIPTION

The

spark

timing
control

system
is

designed
to
control

the
distributor

vacuum
advance

under

varying

driving

conditions
so

as
to
reduce
He
and

NOx
emissions
Emission
Control

System

mal

vacuum
valve

opens
or
closes
in

response
to

engine
coolant

tempera

ture

as

specified

Thermal

vacuum
valve

should

open

at

a

temperature
specified
below

com

pleting
the
vacuum

passage

Thermal

vacuum
valve

opening

temperature

40
to

63
c
104
to
1450

Fl

CAUTION

00

not
allow
water
to

get
inside
the

thermal1
acuum
valve

Jl
i

g

J

eC
42

Fig
EC
78
Ch

ckjng
Thermal
Vacuum

Valve

M
T
model

When

the
transmission

is
shifted

into
the

4th
or
5th

gear
the
electric

current
flows
into

the
vacuum

switch

ing
valve
The
vacuum

switching
valve

is

then
actuated
and

close
the
vacuum

passage
As

a

res
li
the

distributor

fully
advances

its

ignition

liming

When
the
transmission
is

shifted

into

any
gear
other

than
4th
and
5th

current
flow
is

interrupted
The

vacu

umswitclting
valve
is

then
deactuated

and
the

vacuum
leak

passage
is

E026
BoP

T
valve

1

DiSCOIUlect
two
vacuum
hoses

on

BY
T
valve

2

Plug
one
of
two

port
of
BY
T

valve

Apply
a

pressure
above
SO

nimH20

1
97

inHP
to
B
P
T
valve
and

orally
suck
back
other

port
of
B
P
T

valve

as
shown
below

to
check
for

leakage
If

a
leak
is
noted

replace

valve

Apply
pressure
above

SO
mmH10
2
inH10

EC311A

Fig
EC
79

Checking
B
P
T
Valve

opened
This
weakens
the
vacuum

signaUransmitted
from
the
carburetor

As
a
result
the

ignition
timing
of
the

distributor
is

slightly
advanced

On
U
s
A
models

except
for

the

FU
model
a
thermal

vacuum
valve

3

port
type
is
added
on
the

vacuum

line
between
the
carburetor
and
dis

tributor

The
vacuum

signal
is
controlled

by

this
thermal

vacuum
valve

in
accord

ance
with
variation

in

engine
cooling

water

temperature

Emission

Control

System

AfT
models

Spark
timing
control

systems
on

Arc
models

are
divided
into
3

types

On
California

models
a

top
detect

ing
switch
i3

added
on
the
line

pressure

circuit
beside

the
transmission
case
The
vacuum

switching
v
iJve

and

thermal
vacuum
valve

3

port

type

control

the

spark
advance

by
the

engine
cooling
temperature
and

gear

position

On

non
California
models

excpt

AfT
models
Califomle
models

Distributor

To
B
P

T

valve

1
Orifice

i1J

1
ICh

OJ

L
J
To
air

cleaner

Fu

EJ
Top
5witch

D3
R
ON

Others
4
OFF

Battery

Non
californla
models

except
Canada

To
air
cleaner

l

o

o
0

Ig

o

g
00

00
00

r
Vacuum

delay
valve

Thermal

vacuum

valve

Water

temperature

OC
OF
Thennal

vacuum

valve

Oosed
Ignition
timing

Below
5
10
18

41
io
64

Between

5
to

IB
and

50
to
63

411064
and
122
10
145

Above
50
to
63

122
to
145
Fully
advanced

PartiaDy
advanced

Open

Fully
advanced
Oosed

EC2a
Water

temperature

OC
oF

Bdow

51018
41
to
64

Between

5
to
18

and
50
10
63

411064
and

12210145

Above
50
to

63

122
to

145

Distributor

Carburetor

J

l
Canada
the
thermal

vaCUUDl

Vl
lve

3

port
type
and
vacuum
delay
valve

control
the

spark
advance

On

Canada
models
the
vacuum

delay
valve
is
installed

midway
on
the

vacuum

passage
from
the

carburetor

to

the
distributor

Transmission

gear

position
Thermal

vacuum

va1ve
Ignition
timing

R
and

D

3
FuBy

advanced

Other
than

Rnand

D
3
Oosed

Partially

advanced

R

a
gd

D
3

Other
than

R
and

0

3
Partially

advanced
Open

R
aud

D

3
Fully

advanced

Other
than

R
and

m
3
Oosed

Partially

advanced

Canada
models

Vacuum

delay
valve
Distributor

Carburetor

J

l

EC163A

Fig
EC
81

Spark

Timing
Control

Sy
tem

Af1

J

Vacuumswltching
valve

The
vacuum

switching
valve

changes
the

vacuum

passage
by
the

electrical
signa

The
solenoid
installed
in
the
valve

moves
the
needle

valve
and
controls

vacuum
signal
in

order
to

change
the

vacuum
advance

I
c

III

J

IL
jll
J

EC164A

Fig
EC
82
Vacuum

Switching
Valve

Thermal
vacuum
valve

3

port
type

U
S
A
modele

except

FU
model

The
thermal
vacuum
valve
detects

engine
cooling
water

temperature
and

controls
the
vacuum
signal
for
distrib

utor
vacuum
advance
mechanism

This
3

port
type
thermal
vacuum

valve
is

a
2

stage
action

type

That
is

when
the
water

temperature
is
too

low

or

high
the
acuum
signal
is
transmit

ted
to
the
distributor

ffi2
To
air

cleaner

From
B
PT

valve

From
distributor

EC156A

Fig
EC
83
Thermal
Vacuum
Valve

3

port
type

Top
detecting
switch

For
M
T
models

The

top
detecting
switch
for
M
T

models
is
located

on
the
side
face
of

the
transmission

gear
box

A

plunger
of
the
switch
detects
the

position
of
the

striking
rod
and
Emission
Control

System

changes
the

continuity
between

two

lead
wires

EC165A

Fig
EC
84

Top
Detecting
Switch

Top
detecting
switch

For
Celifornla
AfT
model

The

top
detecting
switch
for

Arr

models
is

installed
as
a

plug
for
t
e

governor
feed
line

pressure
take
out

port
for
service

This
switch
detects
the
line

pressure

for
the
band

servo
release
side
and

front
clutch
and

changes
the
continui

ty
between
lead
wires
to
the

switch

body

EC166A

Fig
EC
85

Top
Detecting
Switch

AfT
model

Vacuum

delay
valve

The
vacuum

delay
valve
prevents
a

rapid
vacuum

change
in
the
distributor

vacuum
advance
line
This
valve
is

designed
for

one

way
operation
and

consists
of
a
one

way
umbrella
valve

and
a

sintered
steel
fluidic
restrictor

B

P
T
valve
side

J

l

1

Sintered
metric
disc

2
One

way
unbreUa
valve

EC860

Fig
EC
86
Vacuum

Delay
Value

EC

29
In
line
orifice

Some
orifices
are
installed
in
the

midway
at

the
vacuum
line
The
size

of
the

orifice
is

important
to
control

vacuum
advance

Therefore

pay
attention

not
to
lose

them

and
install
a

proper
part
when

replacing

Orifice

EC167A

Fig
EC
87
In
line

Orifice

REMOVAL
AND

INSTALLATION

f
Vacuum

switching
valve

The

vacuum

switching
valve
is

located
on
the

rear
end
of
the

intake

manifold

I
Disconnect

a

pair
of

lead
wires

from
valve
and

two
rubber
tubes

2
Loosen
two

screws

securing
valve

to
intake
manifold

Vacuum

switching

valve
can
then
be
taken
out

3
Installation
is
in
the
reverse

s

quence
of

removal

EC16BA

Fig
EC
88

Removing
Vacuum

Switching
Valve

Top
detecting
switch

For
M
T
models

The

top
detecting
switch
is

located

on
the

side
face
of

the
transmission

gear
box

I
Disconnect

a

pair
of
lead
wires

2
Unscrew
the
switch

body
itself

The

switch
can
then
be
taken

out

3

Installation
is
in
the
reverse
se

quence
of
removal

dl
Tightening
torque

Top
cietectingswitch

2
0
to
3
0

kll
m

14
to
22

fHbl

@

EC892

Fig
EC
89

Remouing
Top

Detecting

Switch

Top
detecting
switch

For

AfT
models

The

top
detecting
switch
is

installed

on
the
side
face
of
the

gear
box

I

Disconnect
a
lead
wire

for

top

switch

2

Loosen
switch
itself

Switch
can
then
be
taken
out

Note

When
the

switch
is

remo
ed

automatic

transmission
fluid

flows

out

Prepare
some

rugs
to

prevent
the

fluid
rom

flowing
out

EC169A

Fig
EC
90

Remouing
Top

Detecting

Switch

An
models

3

Insta
tion

is
in

the
reverse
se

quence
of

removal
Emission
Control

System

dl
r

ingtorq

Top
detecting
switch

2
0
to
3
0

kll
m

14

to
22
ft

bl

Thermal
vacuum
valve

3

port
type

The

thermal
vacuum
valve
is
instal

led

on
the
rear
end
of

the

engine

cylinder
head

I

Drain

engine
coolant
about

one

liter

lUllS
qt
Ulmp
qt

2

Remove
manifold

nut

securing

heat
shi
eld

plate

r

l

EC170A

Fig
EC
91

Remouing
Hoot
Shield

Pwte

3
Disconnect
3
vacuum
hoses
and

unscrew
valve

itself
Valve
can
then
be

taken
out

4
Install

thermal

vacuum
valve
in

the

reverse

sequence
of

removal
At

this
time

the
valve
should
be

tighten

ed
to

a
tilt

angle
of
300

Note
Be
sure
to

apply
oealer
to

threads
o
the
valve

prior
to
instal

ling
new

valve
t
J
T1g11taning
torqUe

Thermal

cuum
waive

Less
than

2
2

kll
m
16
ft

bl

Manifold
nut

1
5

to
2

0kg
m

11
to
14
ft

bl

From
distributor

From
B
P
T

valve

From
air
cleaner

ECl71A

Fig
EC

92

mtalling
Thermal
Vacuum

Value
3

port
type

Vacl
ul11

delay
valVe

The
vacuum

delay
Valve
is

installed

on
the

midway
o
the
vacuum
tube

between

the
carburetor
and
distributor

vacuum
advance
mechanism

In

installing
the
valve
make
sure

that
the
brown
face

sid
is
connected

to
the
carburetor

side

Carburetor
sid

C
r

i

J

EG
30
Distributor

side

One
way

umbreDa
valve

Sintered
metal
disc

EC277

Fig
EC
93
In

tolling
Vacuum

Deloy
Value

INSPECTION

Entire

system

U
S
A
MIT

models

except
FU
mo

el

1
Ensure
that

wiring
connectors
are

tight
in

pla
ce

2
Ensure
that

vacuum
hoses

are

properly

cof
1o
c
ed
to

their

positions

3
Ensure
that
distributor
vacuum

controller

properly
functions

4

Set

timing
light
and
start

engine

S

While

engine
cooling
water
tem

pefature
is
below

SOOC

I220F

check
function
of

system
as
follows

WARNING

To

protect
against
accidental
for

ward

surge
engage

parking
brake

firmly
while
above
check
is

being

made

I
Run

engine
and

keep
it

at

ap

proximately
1
600

rpm

2

Disengage
clutch
Shift

gears
in

top
3rd
then
neutral

positions
Read

spark

timing
in

respective
shift

posi

tions

The

system
is

properly

functioning

if

spark
timir
g
does
not

change

If
t

changes
check
thefmal
vacuum

valve

3

port
type

Note

Ensure
that
thermal
vacuum

wIve

is
closed
when

cooling
water

i
below

5
to
lSoC
41
to

640F
or

above
SO

to
630C
122
to
14S0F

I

6

After
the

engine
has
been

warmed

up
sufficiently
check
the

function
of
the

system

again
in
the

I

Same
manner

The

system
is

properly
functioning

if

spark
iimin
advances
in

top
posi

tion

If

not
check
thefmal
vacuum
valve

control

circuit
or
vaeu
um

switching

valve

Entire

system

FU
model
and

Canada
MIl
models

I
Ensure
that

wiri
lg
connectors
are

tight
in

place
Emission

Control

System

2

Ensure
that

vacuum

hoses
are

properly
connected
to
their

positions

3

Ensure
that

distributor
vacuum

controller

properly
fu
ctions

4

Set

timing
light

WARNING

To

protect

against
accidental
for

ward

surge
engage
parking
brake

firmly
while
above
check

is

being

made

5
Run

engine
and

keep
it
at

ap

proximately
1
600

1
m

6

Disengage
clutch
Shift

gears
in

4th

5th
ihen
neutral

positions
Read

spark
timing
in

respective
shift

posi

tions

The

system
is

properly
functioning

if

spark
timing
advances
in

top
gear

position

If

spark

timing
does
not

vary
at
all

in

tests
des
rilied

in

step
6
above

check

control
circuit
or

vacuum

switching
valve

Entire

system

California
AIT
models

I
Ensure
th
t

wiring
connectors

are

tight
in

place

2

Ensure
that
vacuum
hoses
are

properly
coIDwcted
to

thejr
positions

3

Ensure
that

distributor
vacuum

controller

function
s

properly

4
Set

timing
light
and
staft

engine

S

While

engine
cooling
water
tem

perature
is
below
SOOC
1220F

check
the
function
of
the

system
as

follows

WARNING

To

protect
againSt
accidental
for

ward

surge
engage

parking
brake

firmly
while
above
check
is

being

made

I
Run

engine
and

keep
it
at

ap

proximately
1

600

rpm
at
P

range

2

Make
a

short
circuit

between
the

specified
two
terminals
at
function

te
t

connector

EC31
The

entire

system

except
for
the

top
switch
is

properly

functioning
if

spark
timing
does
not

change
If

it

changes
check
the

thermal
vacuum

valve

3

pori

type

CAUTION

Pay
attention
not
to
make
a
short

circuit
between
other
terminals
than

the

specified
terminals
or
electrical

system
of
car
will

get

damaged

4

EC328A

Fig
EC
94

Making
Short
Circuit

6

After
ihe

engine
has
been

warmed

up
sufficiently
check
the

function
of
the

system
again
in
the

same
manner

The

system
except
for
the

top

switch
is

properly

fU
lctioning
if

spark

timing
is

approximately
greater
than

that
without

a
short
circuit

If

not
check
the

thermal
vacuum

valve

control
circuit
or

vacuum
switch

ing
valve

7
As
the
final

step
of

checking

entire

system
top
switch
should
be

checked

as
follows

1
Start

engine
and

keep
at

idling

speed

2

Disconnect
lead
wires
from
vacu

um

switching
valve

at
connetors

CAUTION

Never

forget
this

operation
otherwise

the
circuit

tester
will

get
damaged

EC173A

Fig
EC

95

Disconnecting
Vacuum

Switching
Valve
Connector

3

Apply
parking
brake
and

keep

brake

pedal
fully

depressed

4

Check

continuity
between
two

specified
terminals
ai

function
test

connector
with

gearshift
lever
in
R

or
N

position

The

top
detecting
switch
is

func

tioning
properly
if
the

continuity
is

as

following
table

If
not

replace
the
switch

N

position
No

R

position
Yes

Note
At

idling

CAUTION

Never

race
the

engine
or
car
will

creep

r

q

EC329A

Fig
EC
96

Checking
Top

Detecting

Switch

Arr
model
Emission
Control

System

Entire

system

Non
California
AfT
models

except
Canada

1

Ensure
that
vacuum

hoses
are

properly
connected
to

their

positions

And

confirm
that

gearshift
lever
is
in

P

position

2
Disconnect

vacuum
hose
atdis

tributor

vacuum
controller

3

While

engine
cooling
wat
r

is
be

low
SOoC

1220F
race

engine
and

check
vacuum
for
distributor
If
vacu

um
is
felt
check

thermal
vacuum
valve

3

port
type

4

After

engine
is

sufficiently

warmed

up
repeat
the
above

opera

tion

In

this
case
vacuum
should
be
felt

If
not
check
thermal

vacuum
valve

Vacuu
m

switching
valve

If

spark
timing
does
not

vary
at
all

in

checking
entire

system
check
vacu

um

switching
valve
i
follows

I
Warm

up
engine

sufficiently

2

Disconnect

vacuum

switching

valve

lead
wires

3

Set

timing
light
and

keep
engine

speed
at

approximately
1

600

rpm
On

AfT
models

geaishiftlever
should

be

in

N
or
P

4

Apply
l2V

battery
voltage
to

one
of
two

lead
wires

from
vacuum

switching
valve
Then
connect
the

other
lead
wire

to

ground

At

this
time

spark
timing
should

change

appioximately
by
50

If
it
does
not

replace
vacuum

switching
valve

EC175A

Fig
EC

97

Checking
Vacuum

Switching
Valv

Thermal
vacuum
valve

3
port

type
U
s
A
models

except
FU

model

Remove

thermal
vacuum

valve
from

engine
Inhale
air
from

port
of

spark

EC32
timing
amttol

systetn
andcheck
to

sure
that

thermal
vacuum
valve

opens

or
closes
in

response
to
its

tempera

ture

Thermal

vacuum
walye

closing

temperature

Above
50
to

63
c

122
to
1450
F

Below
5
to

1SoC

41
to

64
Fl

J

EC161A

Fig
EC
98

Checking
Thermal

Vacuum

Valv

CAUTION

Do

not
allow

water
to

get
inside

the

thenna

vacuum
valve

Top
detecting
switch

M
T
models

To

check

top
detecting
switch
for

proper
ON
OFF

operation
contact

leads
of

an
ohmmeter

with
swiich

lead

wires
and
shift
transmiosion

from

TOP
to
other
forward

gear
and

vice

versa
If

switch
does
not

operate
prop

erly
replace

Continuity
of

top
detecting
switch

should
be

a
follows

Other
than

4th
and
5th
No

4th

and
5th

Yes

Note
In

checking

continuity
oCthe

switch

keep
the

ignition
switch

OFF
Otherwise
the

circuit
tester

will

get

damaged