1979 DATSUN 210 carb

DESCRIPTION

The

carburetors
are

of
downdraft

two

barrel

type

designed
to
increase

ppwe
r
a
fu
l
eC

l
Il
Y
t

3
ell
a

to

reduce

exhaust

gas
emissions

These
carburetors

present
several

distinct
features
of

importance
to

car

owner

A

summary
of

features
is
as
fol

lows

1

Secondary
throttle
valve
is

oper

ated

by
throttle
lever

High
power
and

good
acceleration
are

gained
with
com

bination
of
the

auxiliary
valve

2

Accelerating

pump
provide
ex

cellent
acceleration

3
Power
valve
mechanism
is

a
vacuo

urn
actuated

boost

type
and

improves

high
speed
driving

4

The
throttle

opener
control

sys

tem

Except
FU
model

incorporates
a

servo

diaphragm
which

helps
open
the

throttle
valve
at

a

decreasing
speed
so

as
to

reduce

hydrocarbon
emissions

to

a
minimum

5
An
anti
d

eseling
solenoid

valve
is

installed
to

prevent
dieseling
When

ignition
key
is

turned
off
the

fuel

passage
involved
in
the
ow

system
is

closed
and
the
fuel

supply
is
shut

down

completely

The
solenoid
valve
also

serves
as
an

actuator
of
the
fuel

shut
off

system
on

the

FU
model

6
In
the
choke
mechanism
an

elec

trie
automatic

choke
is
used

to
auto

maticaDy
control
chok
valve

opera

tion

during
engin
war

up

7

The
carburetor
comes

equipped

with
dash

pot
which
ensures
smooth

deceleration
without

engine
stall
under

aU

operating
conditions

STRUCTURE
AND

OPERATION

These
carburetors
consist
of
a

main

system
for
normal

running
a
slow

system
for

idling
and

an

accelerating

and

power
mechanisIll

Some

emission
control
devices

are

added
E
ngine
Fuel

CARBURETOR

I

J

1

Primary
main

jet

2
Idle

adjust
screw

3
hUe
nozzle

4

By
pass
hole

5

Primary
throttle
valve

6

Primary
slow

jet

7

ptug

8

Primary
5l

w
air
bleed

9

Primary
main
air
bleed
10

Primary
air
vent

pipe

11

Primuy
main

nozzle

12

Choke
valve

13

Primary
small

venturi

14

Secondary
small

venturi

15

Secondary
air
vent

pipe

16

Secondary
main

nozzle

17

Secondary
main
air
bleed

18

Secondary
slow

air
bleed

1
Oloke
valve

2

Primary
air
vent

pipe

3
Prima
y
main
nozzle

4

Primary
slow

jet
19

Plug

20

Secondary
slow

jet

21

Needte

22
Fuel
fLlter

23

Secondary
tIuottle

valve

24

Auxiliary
valve

25

Secondary
main

jet

Note
Do
not
remo
the

parts
inarbd

with
anuteriak

EF416A

Fig
EF
17
Carburetor

PRIMARY

SYSTEM

PrlinarJ
main

sJstam

The
fUel

flowing
out
of
the

passages

at
bottom
of

float
chamber

passes

through
the

primary
main

jet
and
is

mixed
with
air

coming
from
main
air

bleed
The

gas
mixture
is

pulled
out

into
the

venturi

through
the
main

nozzle

When

throttle
valve
is
wide

open

and

engine
require
dense
mixture

gas

power
valve

opens
and
fuel
also
flows

into
main

system

EF044A

Fig
EF
18

PtJrlially

Loading

EF
8

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

Fuel
shut
oH

s
stein

operation

During
deceleration
when

the
en

gine

speed
is

above
a
certain
level
the

anti
dieseling
solenoid
valve
of
the

carburetor
closes
so
that
the
fuel
is

shut
off
When

engine
speed
falls

below

a
certain
level
the
anti

dieseling

solenoid
vaJv

oP
lS
so
that

the

f
el

flows
However

if
the

engine
speed
is

below
the

designated
level

even

during

deceleration
the
fuel

shut
off

system

does
not

operate
When
the
shift
lever

is
in
neutral

the
fuel

shut
off

system

does
not

operate

The

functions
of
each

part
of
this

system
are
as
follows

I

Engine
revolution
switch

The

engine
revolution

switch
turns

off
when

the

engine
revolution
is

above
2

100

rpm
and
turns

on
when

the

engine
revolution
falls
below
1

650

rpm
This
switch
is

actuated

hy
a

pulse

of

the

ignition
system

This
switch
is

located
on
the

right

hand

dash
side

panel
in
the

passenger

compartment
as
shown
in
the
follow

ing
figure
Engine
Fuel

I

Fig
EF
28
Location

of

Engine

Revolution
Switch

2

Neutral

detecting
switch

The
neutral

detecting
switch
turns

on
in

neutral
and
turns
off
in

other

shift

lever

positions

h

1

Neutral

detecting
switch

2

Revenelamp
switch

3

Top

detectim
switch
EC275
3
Throttle
valve

switch

The

throttle
valve

switch
is

installed

on

the
carburetor
It

turns
off
when

the

throttle
valve
is
closed

and
turns

on
when
the
throttle

valve
is

open

The

opening
position
of
the

throt

tle
valve

switch
is
calibrated
in

engine

rpm
when
the

engine
is
revved

up

under

no
load

The

switch
turns
on
when

the

engine
revolution
is

above
1

150

rpm

and

turns
off
when
the

engine
revolu

tion
is

below
1

000

rpm

1
Micro
switch

2

Connector

3

Adjusting
screw

EF848

Fig
EF
30
Location

of
Throttle

Valve
Switch

Fuel
shut
off
Anti

dieseling

Engine
revolution
Throttle
valve

opening
Shift
lever

position

system
solenoid
valve

Activated

Closed

Except
neutral
OFF

Closed
OFF

Neutral

ON

High
OFF

Except
neutral
OFF

Open
ON

Inactivated

Open
Neutral
ON

Closed
OFF
Excep
t
neutral
O
F

Low
ON
Neutral
ON

Except
neutral
OFF

Open
ON

Neutral
ON

Continuity
of
switch
Fig
EF
29
Locotion

of
Neutral

Detecting
Switch

EF
12

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

FAST

IDLE

I
Remove
carburetor

assembly

from

engine

2
Remove

bi
metal
cover

3

Place
fast
idle
arm
on
second

step

of
first
idle
cam
Then

adjust
fast
idle

adjusting
screw
as
shown
at
A
in

illustration

The
clearance
A

should
be

specified
value
in
the

following
table

4

To
check
fast
idle
cam

setting
by

engine
speed
proceed
as
follows

Warm

up
engine
sufficiently
Set

fast
idle

cam
at
2nd

step
and
read

engine

speed

Fast
idle
cam
is

properly
set
if

engine
speed
is
within

above

specifica

Hons

VACUUM
BREAK

I
Close
choke

valve
completely

2
Hold
choke
valve

by
stretching

rubber
band
between
choke
shaft
lever

and

stationary

part
of

carburetor

3
Push
vacuum
break

stem
with

plie
and

puD
fully
straight

4
Under

this
condition

adjust
gap

shown
at
8
in

illustration
between

choke

valve
and
carburetor

body

Clearance
Bu

All
model

except
FU
model

1
80
to
1
98
mm

0
0709
to

0
0780
in

FU

model

1

98
to
2
16
mm

0
0780
to
0
0850

in
Engine
Fuel

Clearance
A

mm
in
Engine
speed

rpm

Manual
transmission
0
73

to
0
87

0
0287
to

0
0343

1

00
to
1
14

0
0394
to

0
0449
2

400
to
3
200
1
900
to
2

700

Automatic

transmission

Fast

idle
earn

steps

g
g
2
5
t

to
J

A
ti

Ogc
j
jdle
adjusting
screw

o

0

II
r

Throttle

chamber

EF098A

Fiil
EF
35

Adjusting
Fast
Idle

@
B

@

cv

Push

I

4

Choke
valve

5

Vacuum
break
stem

EF885
1
Rubber
band

2

Vacuum
break

stem

3
Vacuum
break
rod

E
F099A

Fig
EF
36

Adjwtirig
Vacuum
Break

EF
15

CHOKEUNLOADER

I
Close
choke
valve

completely

2

Hold
choke

valve

by
stretching
a

rubber

band
between
choke
shaft
lever

and

stationary
part
of

carllUretor

3
Pull

throttle
lever
until
it

com

pletely
opens

4
Under
this
condition

adjust
clear

ance
e
See
illustration
between

choke
valve
and
carburetor

body
by

bending
unloader

tongue
See

Fig

EF
37

Clearance
C

All

modelS
ex

pt
F
U
model

2
36

mm
0
0929

in

FU
model

2
17

mm
0
0854
in

Note
Make

sure
that
throttle
valve

opensfuDy
when
carburetor
is

mounted

on
car

If
throttle
valve
fails
to

open
fully

unloader
becomes

inoperative
re

suiting
in

poor
acceleration
after

engine
is
started

AUTOMATIC

CHOKE

HEATE
IRCUIT

Checking
heater

circuit
with

function

connector

CAUTION

00

not
attach

test
leads
of
8
circuit

tester
to
those
other
than

designated

I

With

engine
not

running
check

for

continuity
between
A
and

B

If

continuity
exists
heater
is

fune

tioning
properly

If

continuity
does
not
exist

check

for
discon
nected

connector
or

open

P
T
C

heater
circuit

2

With

engine
running
at

idle
check

for

presence
of

voltage
across
A

and
B

If
voltmeter

reading
is
12
volts

heater
circuit
is

functioning
proper

ly

If
voltmeter

reading
is
zero

check

for
disconnected
connector

open

circuit
or

faulty
automatic

choke

relay

3

Replace
faulty

parts
Engine
Fuel

c

i

CD

1
Rubber
band

2
Unloa
er

tongue

3
Choke
vaJve

f
rC
EC150

Fig
EF

37

Adjusting
Choke
Unloader

SJ

v

1

Ignition
switch

2
Automatic
choke

relay

Engine
stop
ON

Engine
start
OFF
3
Automatic
choke
heater

4
Function
test
connector

5
L
terminal
of
alternator

EF

16
Fig
EF

38
EF433A

Checking
Automatic
Choke
Heater
Circuit

with
Function
Teat
Connector

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

1

Servo

diaphragm
4

Stopper

2
Bracket
5
Link

3
Lock
nut
6
Carburetor

EF732

Fig
EF
56

Adjusting
Seroo

Diaphragm

Adjwting
Screw

FUEL

SHUT
OFF

SYSTEM

Precautions

a

Before

checking
make
sure

engine

is

warmed

up
and
choke
wive
is

fully
open

b

On
air
conditioner

equipped
mod

els
turn
off

air
conditioner
switch

in

steps
I

through
12

c

Keep
clutch

pedal
held
down
with

your
foot
while

depressing
accele

g

f
J

1
Engine
Fuel

rator

pedllI
when
shift
leVer
ISm

any
position
other
than

neutral

Otherwise
car
will

surge
forward

abruptly

Note
Do

not
attach
test
leads
of
a

circuit
tester
to
terminals
other

than
those

designated

Run

engine
at

idling

speed

2
Disconnect

anti
dieseling
solenoid

valve
connector
and
make

sure
that

engine

stops
If

not

replace
anti

dieseling
solenoid
valve

assembly

EF856

Fig
EF

57

Checking
Function

of

Anti
die

eling
Solenoid
Valve

31
A

t

CID

@

V

II
l

To

distributor

T
n

l1on
coon
o

1

Ignition
switch

2
Fuse

3

Anti
dieseling
solenoid

4

Neu
tral

detecting
switch
5
Throttle
valve
swltch

6

Engine
revolution
switch

7

Transistor

ignition
unit

8
Function
test
connector

Fig
EF
58

Checking
Fuel
Shut
off

System
Operation
with
Function

Test
Connector
EF436A

EF
22
3
Conilect
anti

ieselingsolenoid

valve
connector

4
Restart

engine

5
Connect

circuit
tester

as
shown
in

Fig
EF
S8

6

Depress
clutch

pedal
and

shift

gears
into
5th

position

7

Depressing
clutch

pedal
increase

engine
speed
to

about
3

000

rpm
by

depressing
accelerator

pedal
Then

quickly
close
throttle
wIve

by
re

leasing
accelerator

pedal

8
At
this
time
check

for

presence

of

voltage
across
A

and
B

I
If

voltmeter

reading
i
ero
dur

ing
acceleration
and
is
12V

during

deceleration
fuel
shut
off

system
is

functioning

2
If

voltmeter

reading
is

zero
or

l2V
in

both

engine
operations
fuel

shut
off

system
is

malfunctioning

In

any
case
continue
with
the

following
items

9

Shift
lever
to
neutral

then
in

crease

engine
speed
and

quickly
close

throttle
valve

If

voltmeter

reading
is

zero
in
both

engine
operations
and
results
of
test

i
tern

8
are
correct
neutral

detecting

switch
is

functioning
properly
If
not

check
neutral

detecting
switch
harness

and
connections

Replace
if

necessary

10
Turn

off

ignition
switch

II

Disconnect
throttle
valve
switch

connector
and
connect

circuit
tester

to
throttle
valve
switch
connector

12

Run

engine
under

no
load
In

crease

engine

speed
slowly
and
make

sure

engine
speed
is
within
the

speci

fied

range
when
throttle
valve
switch
is

turned
on

Then

decrease

engine
speed
slowly

and
make
sure

engine
speed
is
within

the

specified
range
when
throttle
valve

switch
is
turned

off

If
not

adjust
throttle
valve

switch

13
In
air

conditioner

equipped

models

proceed
as
follows

I
Check
F
l
C
D

rpm
and
correct

if

necessary

2
With

air
conditioner
in
ON

F
l
C
D
is
actuated
increase

engine

speed
slowly
then
decrease
it
And

make

sure
throttle
valve

operates

Click
sOund
is
heard
or

continuity

turns
to
OFF
when

engine
speed

decreases
to

idling