AUX DATSUN 210 1979 Service Manual

Page 93 of 548


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

Page 94 of 548


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

Page 95 of 548


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

Page 109 of 548


En9ineFuel

DISASSEMBLY
AND
ASSEMBLY

Except
FU

model

A

JS

@fB

@
Choke

chamber

@
Center

body

@
Throttle

chamber

1

Servo

diaphragm
of
throttle

opener

2
Dash

pot

3

Automatic
choke

cover

4

Automatic
choke

I
ody
and

diaphragm
chamber

S

Accelerating

pump
lever

6

Auxiliary
valve

7

Venturi

stopper
screw

8

Primary
and

secondary
maU

venturi

9

Secondary
slow

jet
I

I
l

c
I
liO

JCJ

@

c

1
@

11
i

I

rJ

@

10

Power

valve

11

Secondary
main
air

bleed

12

Primary
main
air
bleed

13

Injector

weight

14

Primary
slow
air
bleed

15

Accelerating
pump

16

Plug

17

Primary
slow

jet

18

Needle
valve

19

Float

20
Anti
c1ieseling

solenoid
valve

21

Primary
main

jet

22

Secondary
main

jet
23
Idle

limiter

cap

24
Idle

adjust
screw

25

Spring

26
Throttle

adjust
screw

27

Spring

28

Primary
and

secondary
throttle

valves

29
Fast
idle

adjust
screw

30

Accelerating
pump
rod

31
Throttle
retum

spring

32
Stroke
limiter

Note
Do
nOt
remove
the

puts

marked
with
an
uterisk

EF420A

Fig
EF
60
c
rburetor

EF
24

Page 112 of 548


Engine
Fuel

Choke
chamber

parts

FU

model

Except

FU
model
R

5

7

@

l
i

1

I
ft

Y

mJ

r

ft
1
@

@

1

EF421A

Tl@@

EF568A

EF
27
1

Secondary
slow

jet

2

Plug

3
Power
valve

bleed
d
mam
au
4

Seeon

ary

bleed
P

imary
maID
aIr

5
r

ight
6

Injector
we

7

Plug

t
8

Primary
slow

Je

d

valve
9
Anti
dieseling
solenOl

t
O
P

imary
malO

Je
1
r

main

Jet
11

Secondary

iliary
valve
12
Aux

screw
13
Venturi

stopper

duv

small
nd

seeon
J
14
Prima
a

ventuns

tl
not
J

eIIlove

the
p
Note
Do

tIt
an

asterISk
markedwt

CENTER

BODY
PARTS

slow

jet
1

Secondary

aU
yen
turi
2

Secondary
sm

Yen
turi
3

Primary
small

4
Power
valve

n

air
bleed
5

Secondary
m3J

6

Plug

on

air
bleed
7

Primary
mm

8

Plug

9

nJ
eetor

weight

pump
10

Accelerating

11

Plug

et
12

Primary
l
w

J

lenoid
valve
13
An
ti
dieseling
50

mamJet
14

Secondary

t
IS

Primary
mamJc

ill

y
valve
16
Aux
ar

the

parts
Do
not

remOVe

t
Note

th
an
utens
marked
WI

EF

63
Center

Body
FIg

Page 257 of 548


OIL
CHANNEL

IDENTIFICATION

The
circuit
numbers
shown
in
each

Hydraulic
Control
Circuit
are

classified

as
follows
according
to
the

function

Pressure
source
of
the
line
7

Operating
line

pressure
for

friction
elements

I
2
3
4
5
6

g
9

10
11
12

Auxiliary
line

pressure
13

Torque
converter

pressure
14

Governor

pressure
15

Throttle

system
pressure

16
17
18

19

Oil
pump
discharge
hole
7

f
Torque
converter

pressure
14

Rear
clutch

pressure
1

Front
clutch

pressure
11

W
h0i1
pu
6
suction
hote

e

8

IIlIlJJIII
Automatic
Transmission

L

f

AT106

Fig
AT
5

Oil
Channela
in
Cou
Front
Face

lo
o

o
0

Oil

pump
discharge
hole
7
Governor

pressure
15

1

h

Torque
converter
I

pressure
14
0
0

Servo
release

Rear
clutch

l
press
re

10
r

L

Governor
reed

pressure
1

pressure
1
Servo

tlghtemng

li
nb

o

0

pressure
9

r

Front

clutch
fI
Low
reverse
brake

pressure
12

pressure
11

U
0

111
1

1
P
u
n

e

AT107

ATlOS

Fig
A
T
4

Oil
Channell
in
Oil
Pump
Fig
A
T
6
Oil
Channell
in
Cou
Fac

MECHANICAL
OPERATION

In

the
3N71B
automatic
transmis

sion
each

part
operates
as
shown
in

the

following
table
at
each
gear
select

position
RanKe
Cm

ratio
Clutch
Low
A

Front
Rear

brake
One

w

y

dutch
Parkin

pa
l
Band
servo

Operation
Release

Park
on
on

Reftrst
2
182
on

on
on

Neutral

Dl
Lo
2
458
on

on

Drift
02
Second
1
458
on

03

Top
1
000
on
on
on

2
Second
1
4
8
on
on

12
Second
1458
on
on

Low
2
4
8
on
on

Note
The
low
brake
is

applied
in

11
raiW
to

prevent
free
whee6ng

when
coasting
and
aIlows
engine

braking

AT
5