light DATSUN 210 1979 User Guide

t

1

Primary
main
nozzle

2

Primary
main
air
bleed

3
Primary
slow
air
bleed

4

Primary
slow

jet

5

Primary
main

jet

6
Idle
nozzle

7

Primary
throttle

valve

EF417A

Fig
EF
I9

Portially
Loading

IdUns
nd
slow

system

Passing
through
the
main

jet
the

fuel

passage
is

separated
from
main

line
fuel
flows

through
the
slow

jet

primary
slow
air
bleed
is

ejected
from

the

by

pass
hole
and
idle
nozzle

cp
v

Ii

l

1

Primary
main
air
bleed

2

Primary
slow
air

bleed

3
Anti
fieseling
solenoid
valve

4

Primary
main

jet

5
Idle
nozzle

6

Primary
throttle

valve

EF711

Fig
EF

20

Idling
and
Slow

System

Aceeler

tlns
meeh

nlsm

A

mechanical

accelerating

pump

synchronized
with
the
throttle
valve
is

used
Engine
Fuel

When
throttle
valve
is
closed

piston

rod

is

pushed

up
wi
th

linkage
which

pushes
up
piston
through
piston
return

spring

When

piston
comes
down
inlet

valve

closes
outlet
valve

opens
and

fuel
within
the

pump
is

blown
out

from
the

pump
je
t

by
compressed

piston
return

spring
The
fuel
hits

against
side
wall
of
small
venturi

becoming
minute

drops
and

compen

sating
transient

spareness
of

fuel

1

r

@
CD

V

1
Piston

2

Pump
lever

3

Pump
nozzle

4
Piston

return

spring
5
Inlet
valve
EF239

6
Outlet
valve

7

Primary
throttle
valve

8

Pump
connecting
rod

Fig
EF

21
Accelerating
Mechani
m

Power
v
lve
meeh
nlsm

The
vacuum
actuated
boost

type

power
va
v

mechanism
makes
use
of

the
downward

pulling
force
of
the

air

stream
below
throttle
valve

When

throttle
valve
is

slightly
open

ed

during
light
load

running
a

high

vacuum

p
ston

upward
against
the

spring
leaving

power
valve
closed

When
vacuum

is
lowered

during
full

load

or
acceleration
the

spring
pushes

vacuum

piston
downward

opening

power
valve
to

furnish
fuel

I

t
f

i

1
Vacuum

piston

2
Power
valve

EF240

Fig
EF

22
Power
Valve

EF
9
SECONDARY
SYSTEM

Second

ry
m

ln

system

When
the

primary
throttle
valve
is

wide

open
and

engine
produces
high

power
the

secondary
throttle
valve

begins
to

open
by
the

linkage

However

auxiliary
valve
does
not

open
at
a
slow

speed
due

to
counter

weight
connected
to
valve
shaft

As

engine
picks

up
speeds
the

auxiliary
valve

opens
against
the

load

of

counterweight
and

secondary
sys

em
starts

operation
for

high

power

operation
The
fuel

flowing
out
of
the

passage
at
bottom
of
float
chamt
er

passes
through
secondary
main

jet

The

fuel
is
mixed
wi
th

air

coming

from
main
air
bleed
and

mixture
is

blown
in
to
the
venturi

through
main

nozzle

When

primary
throttle
valve
is

in

full

open

position

secondary
throt

tle
valve
is

also

fully

opened

I

Secl
ndary
slow
air
bleed

2

Secondary
main

air
bleed

3

Secondary
main
nozzle

4

Primary
main
nozzle

5

Primary
main
air

bleed

6

Primary
slow
air

bleed

7

Primary
slow

jet

8
Primary
main

jet

9
Idle
nozzle

10

Primary
throttle
valve

11

Auxiliary
valve

12

Secondary
throttle
valve

13

Secondary
main

jet

14

Counterweight

15

Secondary
slow

jet

EF418A

Fig
EF

23
At
Full

Open
Stow

Speed

I

Secondary
slow
air

bleed

2

Secondary
main
air
bleed

3

Secondary
main
nozzle

4

Primary
main
nozzle

5

Primary
main

air
bleed

6

Primary
slow
air
bleed

7

Primary
slow

jet

8

Primary
main

jet

9
Idle
nozzle

10
Primary
throttle
valve

II

Auxiliary
valve

12
Seco
dary
throttle
valve

13

Secondary
main

jet

14

Counterweight

IS

Secondary
slow

jet

EF419A

Fig
EF
24
At
Full

Open
High
Speed
Engine
Fuel

Secondary
slow

system

Step
system

The
construction
of
this

system

corresponds
to

the

idling
and
slow

system
of
the

primary
system

This

system
aims

at
the

power

filling
up
of
the

gap
when

fuel

supply

is
transferred
from

the

primary
system

to
the

secondary
system
The

stepport

is
located

near
the

auxiliary
valve
in
its

fully
closed
state

ANTI

DIESELING
SYSTEM

The

carburetor
is

equipped
with
an

anti
liese1i

lg
solenoid

valye

As
the

ignition
switch
is

turned
off

the
valve
is

brought
into

operation

shutting
off
the

supply
of

fuel
to

the

slow
circuit

The

following
figure
shows
a
see

tional
view

of
this

control

An

ti
dies

eling
solenoid
valve

Ignition
switch
OFF

ON

t

L
li

FLOAT
SYSTEM

There
is

only
one
float
chamber

while
two
carburetor

systems

primary

and

secondary
are

provided

Fuel
fed
from
the
fuel

pump
flows

through
the
filter
and
needle
valve
into

the
float

chamber
A
constant
fuel

level
is
maintained

by
the

float
and

needle
valve

Because
of

the
inner
air

vent

type

float

chamber
ventilation
fuel
con

sumption
is

not
affected

by
dirt
ac

cumulated
in

the
air
cleaner
Ignition
switch

Q

1

T
Battery

niT

EC
3

Fig
EF
25

Anti
dieseling
Solenoid
Valve

The
needle
valve
includes

special

hard

steel
ball
and
wiD

not
wear
for
all

its

considerably

long
use

Besides
the
insertion
of

a

spring

will

prevent
the

flooding
at

rough
road

running

THROTTLE
OPENER

CONTROL
SYSTEM

T
O
C
S

Except
FU

model

The
function

of
the
throttle

opener

is
to

open
the

throttle
valve
of
the

carburetor

slightly
while
the
car
is
in

EF
10
deceleration

During
deceleration

the

manifold
vacuum
rises
and

the

quan

tity
of
mixture
in
the

engine
is

not

suffICient
for
normal

combustion
to

continue

4
consequently
a

great

amount
of

unburned
HC
is
emitted

Carburetors

equipped
with

the

throttle

opener
supply
the

engine
with

an

adequate
charge
of

combustible

mixture
to
maintain

proper
combus

tion

during
deceleration

resulting
in
a

dramatic
reduction
in
HC

emission

The

system
for
the

manual
trans

mission
model
consists
of

servo
dia

phragm
vlicuum

control
valve
throttle

opener
solenoid
valve

spee
l

detecting

switch
and

amplifier
On

the
auto

matic

transmission
model
an
inhibitor

and
inhibitor

relay
are
used
in

place
of

speed

detecting
switch
and

amplifier

on
the
manual
transmission

model
An

altitude

corrector
fitted
to
vacuum

control
valve

serves
to

automatically

regulate
the

operating
pressure
in

the

system
with

variation
of

atmospheric

pressure

T
o
C
S
n

operatIon

At
the

moment

when
the

manifold

vacuum
increases
as

occurs

upon
de

celeration

the
vacuum

control
valve

opens
to
transfer

the
manifold

vacuum

to
the
servo

diaphragm
chamber
and

the
throttle
valve
of
the

carburetor

opens

slightly

Under
this

condition
a

proper

amount

of
fresh
air

is
sucked

into
the

combustion
chamber
As
the
result

complete
combustion
of
fuel
is

as

sisted

by
this
additional
air

and
the

amount

of
H
C

contained
in

exhaust

gases
is

dramatically
reduced

Throttle

Clpener
sol
nold

valve

operation

Manual

transmission
models

The
throttle

opener
solenoid
valve

is
controlled

by
a

speed

detecting

switch
which
is

actuated

by
the

speed

ometer
needle

As
the

car

sp
ed
falls
below
16

km
h
10
MPH

this
switch
is
acti

vated

producing
a

signal

The

signal
is

led
to
the

amplifier
so

that
the

signal
can
be

amplified
to

a

degree

large
enough
to
actuate
the

DASH
POT
SYSTEM

These

carburetors
are

equipped

with
a
dash

pot
interlocked
with
the

primary
thrott
Ie
valve

through
a

link

mechanism

The
dash

pot
prevents
the

throttle

valve

from

closing
abruptly
thereby

reducing
He
emissions

during
deceleia

tion
or

gear
shifting

In
automatic

transmissi9fi
models

it

also

prevents
engine
stall

resulting

from

quick
application
of
the
brake
or

from

quick
release
of
the

accelerator

pedal
after
it
s
been
tread

upon

slightly

INSPECTION

AND

ADJUSTMENT

CARBURETOR
IDLE
R
P
M

AND
MIXTURE
RATIO

CO
idle
adjustment
with

CO
meter

Refer
to
Carburetor
Idle

rpm
and

Mixture
Ratio
Section
ET
for
check

ing
and
a

justment

CO
idle

adjustment
without

CO
meter

Non
California
models

Refer
to

Carburetor
Idle

rpm
and

Mixture
Ratio
Section

ETl
fot
check

ing
and

adjustment

Idle

limiter

cap

Refer
to
Idle

Limiter

Cap

SeCtio

ET
for

checking
and

adjustment

FUEL

LEVEL

I

With

engine
idling

visually
check

fuel
level

through
sight
window
of

float
chamber

Fuel
level
is
correct

if
it

is
at
the

indicator

point

Note

Fuel
level
indicator

point
is

located
IS
mm
0
59
in
below

top

of
carburetor

body
H

as
shown
in

Figure
below
Engine
Fuel

EF088A

Fig
EF
33

Checking
Fuel
Level

To

adjust
fuel
level

proceed
as

follows

2

Remove
choke

chamber

3

Turn
down

choke
chamber

to

allow

float
to

come
into
contact
with

needle

valve
and

measure
H

shown

below

When
H

is

approximately
15
mm

0
59
in

top
float

position
is
correct

The

top
float

position
can
be
ad

justed
by
bending
float
seat

Upon

completion
of
the

adjust

ment

check
fuel

level
with

attached

level

gauge

nhH

J

1
Float

2
Float

stopper
3
Float

seat

4
Needle
valve

Fig
EF
34

Adjusting
Floot
Level

EF

14
4

Adjust
bottom
float

position
so

that
clearance

hl
between

float

seat

and
needle

valve
stem
is
1
3
to
I
7
mm

0
051
to
0
067
in
when

float
is

fully

raised
Bend
float

stopper
as

required

5

Install
choke
chamber

6
After

adjustments
in

steps
3
and

4
above
have
been

made
make

sure

that
when
fuel
is
delivered
to
the

float

chamber
the

fuel
level

is
maintained

within
the

specified
value

H

Engine
Fuel

Upon
completion
of

adjustment

make
sure
that

link

system
opera
tes

smoothly
It
is

necessary
to
remove
Carburetor

from

engine
in

adjusting
this
accelera

tor

pump
stroke
limiter

1

Remove
carburetor

from

engine

2

Insert
a
l
l

to
I
S
mm
0

043
to

0
059

in
feeler

gauge
a

piece
of

round

stock
of

proper
thickness
is

best

betwee
l
primary
ca

buretor

throat
and
throtile
valve
ACCELERATOR
PUMP

STROKE

LIMITER

In

rmal
service

operation
this

limiter
should

not
be
removed
or

bent

In
J

0

ID

@

l

1IJl

J
J
00

I
f

oj

G
1
3
IO
2

mm
0
051
IO
004
in

Fig
EF
44
AdjlUting
Acce
rator

Pump
Stroke
Limiter
1
Primary
carburetor
throat

2
Throttle
valve

3
Lever

4

Limiter
5
Piston

6

Pin

7
Feeler

gauge

E
F048A

3

With
throttle
valve
held

open

properly
by
feeler

gauge
check

that

lever

barely
contacts

pin
If
lever
and

pin
are
not
in

contact

bend
limiter
until

proper
contact
is

made

OZ
00
A

fID

1

S

@

4
1

Full

travel
of

lever

f

EF049A
A
1
Lever

2
Correct

contact
area

3
Limiter

4
Pin

5

Pistgn
6
Correct
cont
ct
area

7
Lever

8

Limiter

9
Pin

10
Piston

Fig
EF
45
Stroke
Limiter

DASH

POT

I

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

toucnes

stopper
lever

3

Adjust
position
of
dash

pot
by

tuming
nut
until

engine
speed
is

in
the

specified

range

California

models
Non

Califomia

models

Automatic

transmission
1

900

to
2

100
1
900
to

2
100

Manual
transmission

1
900

tp
2

100
2
300

to
2

500

FU
model

1

900
to
2

100

EF

t8
1
Lock
nut

2
Dash

pot

E

F730

F
ig
EF
4

Ll
dj

ting
h

P
ot

4

Tighten
lock
nuts

5

Make
sure
that

engine
speed

drops
smoothly
from
2

000

to
1
000

rpm
in

about
three

seconds

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

3

Turn
throttle

valve

by
hand

make
sure
fuel
is

injected

through

injector
nozzle

Note
To

check
or

fuel

injection

peep
into
nozzle
rom

upper
side

while

directing
flashlight
beam
to

ward

primary
barrel

ANTI
DIESELING

SOLENOID

VALVI

Start
the

engine
and

keep
at

idling

speed
Disconnect
the

lead
w

e
for
the

anti
dieseling

solenoid
at
the

connec

tor

If
the

engine
does

not

stop
when

the
lead

wire
is

disconnected
the

solenoid
is

stuck
Reconnect
the
lead

wire
and

start
the

engine
Then
turn

off
the

ignition
switch

If
the

engine
does
not

stop
when

the

ignition
switch
is
turned
off

this

indicates
that
the

striking
solenoid

valve
is

stuck
or

short

circuited

If
the

harness
i
in

good
condition

replace
the
solenoid
valve
as
a
unit

following
functions
without

affecting

the

effectiveness
of
the

exhaust
emis

sion
control

system

Minimizes
exhaust

gas
tempera

ture
rise

2
Minimizes

horsepower
losses
reo

sulting
from
air

injection
into
the

exhaust

system

3

Protects

pump
from
excessive

back

pressure

To
carburetor

air
cleaner

Secondary

ir

Not
actuated

To
carburetor

air
cleaner
J

l
Secondary

sir

Actuated

EC294

Fig
EC
18
Air

Pump
Relief
Valve

c
A
C
valve

Californiamodels

The
C
A
C
valve

controls
the

quantity
of

secondary
air
fed
from
the

air

pump
according
to
the
load
condi

tion
and
it

discharges
the

secondary

air
into
the

atmosphere
to

prevent

overheating
of

the

catalytic
converter

This
valve
is

operated
by
intake

manifold
vacuum

and
air

pump
dis

charge

pressure
When
intake
manifold

vacuum
is

small
or
in

the

high
load

range
the
No
2
valve

opens
when
it
is

great
or
in

the
low
load

range
the
No

I

valve

opens
If
air

pump
discharge

pressure
is

large
or
the

engine
is

running
at
a

high
speed
the
No
3

valve

opens
admitting
the
air

pump

discharge

pressure
to
the
No
2
dia

phragm
chamber
of
the
C

A
C
valve
mission
Control

System

and

opening
ihe
No
i
valve
At
this

point
the
No
2
valve

serves
as
a

relief

valve

F
111

air
pump
No
3

valve

EC787

Fig
EC
19

C
A
C
Valve

I
Engine
in
low

speed
and

light
load

When
the

engine
is

operating
under

these
conditions
intake
vacuum
is

high
The
No
2
valve
unitized

with

the
No
I

diaphragm
is

lifted

by
the

intake

manifold
vacuum

pushing
up

the
No
I

valve
These
valves
will
then

stop
at
a

position
where
a

balanced

condition
exists
between
air

pump

discharge
pressure
an
d

spring
tension

acting
on
the

No
I

and
No

2
valves

The

No
2

jiaphragm
however
does

not
move
due

to
low

engine
speed
low

air

pump
discharge
pressure
and

spring

tension

acting
on
the
No

3
valve
For

this
reason
these
valves
are

brought
to

a
balanced
condition

To
intake
manifold

t

i

l

3

Spring

4

ValveNo
3

5
Di

phragm
No
I
I

@

6

Spring

7

Valve
No
1

8
Valve
No

2

EC683

Fig
EC

20

Operation
of
C
A
C

Valve

1

2

Engine
in

low

speed
and

heavy
load

EC12
Wheo
the

engine
is

operating
under

these
cooditions

intake
manifold

vacuum
is
low
and

all
valves

are

balanced

t
To

intake

manUol

U

E

ii

ji
j

Ii
5

LL

jj

Ii
JI

l
Jij

ulJC

1t

To

atmosphere
EC685

Fig
EC
21

Operation
of
C
A
C

Valve
2

3

Engine
in

high
speed
and

middle

load

When
the

engine
is

operating
under

these
conditions
intake

manifold

vacuum
lies

midway
between
1

and

2

above
The
No
3
valve

moves
to

the
left

because
of

high
air

pump

discharge
pressure

To

intake
manifold

t

L

J

f
E

bt

I
5

tfi
11

I

LJr

To

tmg
J
j
1

EC
4

Fig
EC
22

Operation

of
C
A
C

Volve
3

REMOVAL
AND

INSTALLATION

Air
pump
air
cleaner

Loosen

nuts

securing
air

pump
air

cleaner
to

bracket
then
detach
air

cleaner
from
bracket

Air
cleaner
filter

and
air
cleaner
lower

body
are
built

into

a
unit
construction

Replace
air

cleaner
filter
and
lower

body
as
an

assembly

them

b
If
carbon
shoes
are

exposed
beyond

the
rotor
end
face
remove
carbon

shoes
and
clean
shoe

grooves
Reas

semble
carbon
shoes

6

Vane

1
Pack

vane

bearing
with

high

melting

poinf
grease
MIL
G
3S45
A

Es

o
ANDOK260
or

equivalent
and

insert

dummy
shaft
into
the
vane

bearing

STl9900000

EC563

Fig
EC
40

Va
Assembly

2
Install
vane
in

place
on
rotor

uMng
Dummy
Shaft
STl9900000
as
a

guide

Note
The
woes

may

require
6
to
16

km
4
to
10
miles
wear
in
running

time
In
the
event

a

slight
squeaking

still
remains
drive
the
car

about
64

to
80

km
h
40
to
SO
MPH
In

most

cases
6

to
16
km
4
to
10

miles
will
be
sufficient
for
wear
in

7

Shoe

spring

Place
shoe

springs
in

deeper
groave

of
shoe

11

I

11

1

EC123

Fig
EC
4I
Ins

tolling
Shoe

Spring

Note
When

installing
a

shoe

spring

make
sure
that
the
outward
bend

ing
side
faces
in
shoe
and
that
both

ends
of

sJlri
face
in
the
wall
of
Emission
Control

System

shoe

groove
6e
Sure
to

push
spring

in

SO
that

spring
end
face
is
flush

with
rotor

8
Rotor

ring

Install
rotor

ring
by
correctly

align

ing
the
rear
end
face
of
rotor
with

the

on

mark
in
rotor

ring
and

tighten

screws
with

Hexagon
Wrench

ST
98
10000

l
l
Tightening
torque

Rotor

ring
screw

0
5
to
0

7

kg
m

13

6
to
5
1
ft
lb

Fig
EC

42
Installing
Rotor

Ring

9
Removal
of

dummy
shaft

CarefuDy
withdraw

dummy
shaft

from
vane

10
Vane
shaft

Pack
rear

bearing
with

high

melting

pain
t

grease
MIL
G
3S45
A

Esso
ANDOK
260
or

equivalent

Apply
thin

coating
of

grease
to
vane

shaft
and

rotor
ring
and
insert

vanf

shafi
into
its

bearing

Note

a

Do
not

apply
an
undue
stress
to

vane
shaft
when

inserting

b
If
two
vanes
are
dislocated
when

inserting
vane
shaft

correctly
align

Yanes

by
inserting
dummy
shaft

Then
draw
out

dummy
shaft
and

insert
vane
shaft

c
When
wear
occurs
on

vane
shaft
or

when

replacement
of
rear

bearing
is

necessary
replace
rear
rover
assem

bly

J
I

End
cover

Position
end

cover
in

place
Snugly

tighten
the
bolt
close
to
the
dowel

Then

tighten
end
cover

bolts

EC
t6
l
l
Tighteningtnrque

End
cover
bolts

0
7
to
0
9

kg
m

5
1

to
6
5
ft
bl

EC302

Fig
EC
43
lnstolling
End
Cover

12

Pulley

Tighten

pulley
securing
bolts

Tightening
torque

Pulley
securing
bolts

0
75

to
0
90

kg
m

5
4

to
6
5
ft

Ib

INSPECTION

The
following

procedures
are
re

commended
for

checking
and
or

as

certaining
that
the
various

components

of
the

exhaust
emission
control

system

are

opera
ting
properly

The

engine
and
all

components

mu
t
be
at
normal

operating

tempera

tures
when
the
tests
are

performed

Prior
to

performing
any
extensive

diag

nosis
of
the
exhaust
control

ystem
h

must

be
determined
that
the

engine
as

a
unit
is

functioning
properly

Air

injection
s

stem
hoses

Check
air

system
hoses
for
loose

connections
cracks
or
deterioration

Retighten
01

replace
if

necessary

Air

pump

I

Operate
engine
until
it
reaches

normal

operating
temperature

2

Inspect
all
hose
hose
connec

tions
and
air

gaDery
for
leaks
and

correct
if

necessary
before

checking

air

injection

pump

3
Check
air

injection
pump
belt

tension
and
adjust
to

specifications
if

necessary

4

Plug
up
air

discharging
hose

from

C
A
C
valve
California
models

y

o

EC144A

Fig
EC
44

Plugging
C
A

C
Value

Air

Discharging
Hose

California
model

S

Disconnect
air

supply
hose
at

check
valve

6
Insert

open
pipe
end
of
Air

Pump

Test

Gauge
Adapter
STl9870000
in

air

supply
hose

Clamp
hose

securely

to

adapter
to

prevent
it
from

blowing

out
Position
adapter
and
test

gauge
so

that
air
blast
emitted

through
drilled

pipe
plug
will
be

harmlessly
dissipated

7
Install
a
tachometer
on

engine

With
the

specified
engine
speed
ob

serye
air

pressure
A

produced
at
test

gauge

Air

pressure
A

More
than

100

mmHg
3
94

inHg

at
2
600

rpm

I

jff

100
m

Hg

f1

3
94

mHg

I

EC145A

Fig
EC
45

Testing
Air

Pump

8
If
air

pressure
does
not
meet

above

specifications
proceed
as

follows
Emission

Control

System

Non

California
models

1
Repeat
2

and
3
above

2
With

engine
speed
at
1
500

rpm

disconnect
tube

from

adapter
and

close
hole
of

test

gauge
with

finger
If

a

leaking
sound
is
heard

or

leaking
air

is
felt

by
finger
at
relief
valve
relief

valve
is

malfunctioning
Relief
valve

should
be

replaced
or

repaired

3
If
air

injection
pump
does

not

meet
minimum

requirement
of

pres

sure
test
it
should
be

repaired

California
models

Disassemble
the
air

pump
and
re

pair
it

Check
valve

Warm

up
engine
thoroughiy

2
Disconnect

hose

leading
to

check

valve
from
air

hose
connector

3
Check
hose

opening
for

any
indi

cation
of
exhaust

gas
leaks
If
leaks

are

detected

replace
check
valve

4
Race

the

engine
lightly
at
about

2
000

rpm
and
then

return
it
to

idling
Visually
check
the
hose
for

any

indication
of
exhaust

gas
leaks

before

the

engine
returns
to

idling
speed
If

leaks
are
detected

replace
check
valve

EC146A

Fig
EC
46

Checking
Check
Valve

Air
pump
relief
valve

After

completing
inspection
of
air

pump
check
air

pump
relief

valve
in

the

following
steps

I
Disconnect
hoses

leading
to
check

valve
and
air
control
valve
from
air

hose

connector
and
install

blind
c

p

to
the
connector

2
With

engine
running
at
about

3
000

rpm
under

no
load

place
your

EG
7
hand
on
the
air
outlet
of
air

pump

relief
valve
to

check
for

discharged
air

If

no
air
is
felt

replace
the

air

pump

relief
valve

G

EC575

Fig
EC
47

Checking
Air

Pump

Relief
Valve

Anti
backfire
valve

A
B

valve

I
Warm

up
engine
thoroughly

2
Disconnect
hose
from
air

cleaner

and

place
a

finger
near
the

outlet

3
Run

engine
at
about
3

QOO
rpm

under
no

load
then

quickly
return
it

to

idling
If

you
feel
a

pull
or
suction

force
on

your
finger
the
anti
backfire

valve
is

functioning
normally
If

no

suction
is

felt

replace
the
anti
backfire

valve

EC768

Fig
EC
48

Chocking
Anti

backfire

Valve

C
A
C
valve

California
models

I

Make
sure
that

C
A
C

valve
vacu

um

hose
and
air

hose
are

not
cracked

2
Warm

up
engine
throughly

3
With

engine
at
idle

place
your

fmger
over

relief
hose

opening
to

check
for

presence
of
air

4

With

engine
idling
disconnect

vacuum
hose
at
C
A

C
valve

Then
make

sure
that
air
is

discharg

ed
from

C
A
C
valve

C

A
C
valve
is

functioning

properly

if
air
is

discharged
from
it

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

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