ECO mode DATSUN PICK-UP 1977 User Guide

tZrJ

I
Fuel

nipple

2
Fuel
filter

3

Needle

4
Float

S

Primary
main

jet

6
Idle

adjust
screw

7
I
die
hole

8

Primary

bypass
hole

9

Primary
throttle
valve

10

Primary
altitude

compensator

pipe
California
models

11

Secondary
altitude

compensator

pipe
California
models
Engine
Fuel

jli@

I

12
Air
bleed

13
Primary
slow

jet

14

Plug

15

Primary
slow
air

bleed

6

Primary
main
air
bleed

17

Primary
air

vent

pipe

8
Primary
main
nOlzle

Note
Do

not
remove
the

parts
marked
with
an
asterisk

PRIMARY
SYSTEM

Prlmar
main
s
stem

The

primary
main

system
is
a

Stromburg

type
Fuel
flows
as
shown

in

Figure
EF
25

through
the
main

jet

mixting
with
air

which
comes
in

from

the
main

air
bleed
and

passes
through

the

emulsion
tube
and
is

pulled
out

into

the
venturi

through
the
main

nozzle

IdUns
and
slow
s
stem

During
low

engine
speed
as

shown

in

Figure
EF
25

fuel
flows

through

the
slow

jet
located
on
rear

right
side

of
main

nozzle

mixing
with
air

com

ing
from
the
1st
slow
air
bleed

again

mixing
with
air

coming
from
the
2nd

slow
air
bleed
and
then
is

pulled
out
I

III

@

19

Choke
valve

20

Primary
small
venturi

21

High
speed
enricher

air

bleed

22
Richer
nozzle

23
Richer

jet

24

Secondary
air

vent

pipe

into
the

engine
through
the
idle
hole

and

bypass
hole

Adoption
of
the

submerged

type
of

slow

jet
eliminates

such
hesitation
as

occurs
on
sudden
deceleration
of
the

vehicle

Slow
economizer

system
obtains

smooth
deceleration
at

high

speeds

Small

opening
of
the
throttle

valve

at

idling
or

partial
load

creates
a

large

vacuum

pressure
in
the
intake
mani

fld

By
this

vacuum

pressure
fuel
is

measured

through
the
slow

jet
located

behind
the
main

jet
And
air

coming

from
the
1st

slow
air

bleed
is
mixed

with

fuel
in
the

emulsion
hole

This
mixture
is

further
mixed
and

atomized
with
air

coming
from
the

2nd
slow
air

bleed
The
atomized

mixture
is

supplied
to
the

engine
from

EF15
25

Secondary
main
nozzle

26
Secondary
small
enturi

27
D
C
D
D
a

sembly

28

Secondary
throttle
valve

EF722

Fig
EF
25
Sectional
view

of
carburetor

the
idle
hole
and

bypass
hole
via
the

sow

sysem

passage

Accele

atlns
mechanism

The
carburetor
is

equipped
with
the

piston
type
accelerating
mechanism

linked
to
the

throttle
valve
When
the

primary
throttle
valve
shown
in

Figure
EF
26
is
closed
the

piston

goes
up
and

fuel
flows
from
the

float

chamber
through
the
inlet

valve
into

the

space
under
the

piston
When
the

throttle
valve
is

opened
the

piston

goes
down

opening
the
outlet
valve

and
fuel
is
forced

out
through
the

injector

FLOAT
SYSTEM

There
IS

only
one

float
chamber

while
two
l

arburetor

systems
primary

Jnd

st
l

ondary
are

provided

Fuel
fed
from
the
fuel

pump
flows

through
the
filler
and
needle

valve
into

the
flo
t
chamber
A

constant
fuel

level

is
maintained

by
the
float
and

needle
valve

Because
of

the
inner
air

vent

type

of

the
float
chamber
ventilation
the

fuel

consumption
will
not

be
in

fluenced

by
some
dirt
accumulated
in

the
air

deaner

The
needle
valve

includes

special

hard
steel
ball

and
will
not

wear
for
all

its

considerably

long
use
Besides
the

inserrion

of
a

spring
wiU

prevent
the

flooding
at

rough
road

running

BOOST

CONTROLLED

DECELERATION
DEVICE

B
C
D
D

A

Boost
Controlled
Deceleration

Device
B

C
D

D
serves
to

reduce
the

hydrocarbons

He
emitted
from
en

gine
during
coasting

The

high
manifold
vacuum

during

coasting

prevents
the
mixture

from

complete
combustion

because
of
the

reduced
amount
of
mixture

per
cyl

inder

per
rotation

of

engine
with
the

result
that

a

large
amount
of

hydrocar

bons
is

emitted
into
tile

atmosphere

The
B

C
D
D
has
been

designed
to

correct

this

problem

It

opern
tes

as
follows

when
the

manifold

vacuum
exceeds
a

pre
Engine
Fuel

determined

value
the

B
C
D
D
intro

duces

an
additional
mixture

of

opti

mum
mixture
ratio
and

quantity
into

the

manifold

by

opening
a

separate

mixture

passage
in
the

carburetor

Complete
combustion

of
fuel
is
assist

ed

by
this
additional
mixture

and
the

amount

of
H
C

contained
in

exhaust

gases
is

dramatically
reduced

During
the

transition

period
from

coasting
to

idling
the
transmission

produces
a

signal
which
turns
on
the

vacuum
control

solenoid
valve
As
this

takes

place
the
valve
is

lifted
off
its

seat

opening
the

vacuum
chamber
to

the

atmosphere
The
mixture

control

valve
is
then

closed

returning
the

engine
to
the

predetermined
idling

speed

On
manual

transmission
models

this

system
consists

of
B
C
D
D

vacuo

urn
control

solenoid
valve

speed
de

tecting
switch
and

amplifier

On
automatic

transmission

models

it
consists

of
B
C
D
D

vacuum
con

trol

solenoid
valve

and

inhibitor

switch

B
C
D
D

operation

Diaphragm
I

Qj
monitors
the

mani

fold

vacuum
and

when
the

vacuum

exceeds
a

pre
fetermined
value
acts
so

as

to

open
the

vacuum
control
valve

@
This
causes

the
manifold

vacu
urn

to
be

introduced
into
the

second

vacuum
chamber
and

actuates
dia

phragm
ll@

When

diaphrngm
II

operates
the

mixture

control
valve

@
opens
the

passage
and
introduces
the
additional

mixture
into

the
manifold

EF

18
The
amount
of

the
mixture

is
con

trolled

by
the

servo
action

of
the

mixture
control

valve

CID
and

vacuum

control

valve

@
so

that

the
manifold

vacuum

may
be

kept
at
the

pre

determined

value

The
amount

of
mixture

depends

mainly

upon
the

coasting
air
bleed

II@
while
the
mixture
ratio

is
deter

mined

by
the

coasting
jet

@
and

coasting
air
bleed

@
See

Figure

EF
31

Vacuum

control
solenoid

valve

operation

Manual

transmission
models

The

vacuum
control

solenoid
valve

is

con
troDed

by
a

speed

detecting

switch
that
is

actuated

by
the

speed

ometer
needle

As
the
vehicle

speed
falls

below
10

MPH
this
switch
is
activated

pro

ducing
a

signal
This

signal
actuates
the

amplifier
to

open
the
vacuum
control

solenoid
valve

Automatic

transmission
models

When
the

shift
lever
is
in
N

or

P

position
the
inhibitor
switch

mounted
on
the
transmission

turns
on

to

open
the
vacuum

control
solenoid

valve

I
Air

jet

2

Diaphragm
II

3
Mixture
control
valve

4

Coasting
air

bleed
II

5
Mixture
air

passage

6

Secondary
baHel

7
Intake
manifold

8
Boost

passage

9
Vacuum
control
solenoid

valve

10
Vacuum
control
valve

II

Diaphragm
I
Engine
Fuel

12

Secondary
main

jet

13

Coasting
jet

14

Coasting
air
bleed
I

15
Inhibitor
switch
N

P

ON
for
automatic

transmission

16

Amplifier

1
7

Speed
de

tecting
swi
tch
below

10
M
P
H
ON

for
manual

transmission

1

W
j

I

t

i
J

l

J
18

Ignition
switch
CID

1
1

fI3
6

@
I

r
101

@
i

r

@

JJ

Note
Broken
line

applies
only
to
Automatic
Transmission

I

Ignition
switch

2

Amplifier

3

Speed
detecting
switch
below

10
M
P

H
ON
for
manual

transmission

4
Inhibitor
switch
N
p

ON
for
automatic

transmission

5
Solenoid
valve

6
Vacuum
control
valve

7
Altitude

corrector

LlJ

I

I

l

f

L8
J

l
EF231

Fig
EF
31
Schematic

drawing
of
B
C
D
D
Non

California
models

1

J
ru

I

r

lJ

i7

I
To
intake

manifold

To
air

cleaner

E
F235

Note
Broken
line

applies
only
to
Automatic
Transmission

Fig
EF
32
Schematic
drawing
of
RC
D
D

California
models

EF
19

Notes

a

The
idle

rpm
and
CO

vary
accord

ing
to
the
altitude
Therefore

they

should
be

properly
adjusted
when

the

position
of
the
H
L
lever
is

changed

EF729

ADJUSTMENT

AND
INSPECTION

CARBURETOR
IDLE
R
P
M

AND
MIXTURE
RATIO

Cautions

3
On

automatic
transmission

equi

ped
models
check
should
be

per

formed
in

the
0

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
00
not

attempt
to
screw
the
idle

adjusting
screw
down

completely

Ooing
so
could
cause

damage
to

tip

which
in
turn
will
tend
to
cause

malfunctio11ll

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
Engine
Fuel

b
Counties
1

219
m
4
000
ft
or

more
above
sea
level
have
been

designated
by
law
as

High
Altitude

Counties
For

further
details
refer

to
1977
OATSUN
PICK
UP
Service

Bulletin
Pub
No
257

0

I
Air
cleaner

rID
mOl

If
Low
altitude

Ll

n
n

L
n

Fig
EF
34

sert

probe
into
tail

pipe
more
than

40
em

15
7
in

CO
Idle

adjustment
with

CO
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
Ouring
this
10

minutes

proceed
as
described
in

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

EF
21
shown
in

Figure
EF
35

Plug
the
dis

connected
hose

to

prevent
dust

from

entering

0

o

EF259

Fig
EF
35
Disconnecting
air
hose

from
air
check
valve

6
Race

engine
I
500

to
2
000

rpm

two
or
three
times

under
no
load
then

run

engine
for
one
minute
at

idling

speed

7

Adjust
throttle

adjusting
screw

until

engine
is

at

specified
speed

Engine
speed

Manual
transmission

750

rpm

Automatic
transmission

in
0

position

650

rpm

8
Check

ignition
timing
If
neces

sary
adjust
it
to

specifications

This

operation
need
not
be
carried

out
at
1

600
Ian
1

000
miles
service

Ignition
timing

Manual
transmission

120
750
rpm
Non
California

100
750

rpm
California

Automatic
transmission

in
0

position

120

650

rpm

9
At

about
10
minutes

after

engine

is
run

at

idling
speed
adjust
idle

adjusting
screw
so

that
CO

percentage

is
at

specified
level

CO

percentage

Manual
transmission

2
t
l

at
750

rpm

Automatic

transmission

in
0

position

2
t
I
at
650

rpm

10

Repeat

procedures
as
described

in

steps
6

7
and
9
above

so
that
CO

percentage
is
at

specified
level
Check

ing
idle
CO
in

step
9
can

be
carried
out

right
after

step
7

II
Race

engine

1
500
to
2

000

rpm
two
or
three

iimes
under
no

load

and
make

sure
that

specified
CO

per

centage
is
obtained

12

Connect
air

hose
to
air

check

valve

If

engine
speed
increases

readjust
it

to

the

specified
speed
with
throttle

adjustingsqew

CO
idle
edJustment
without

CO
meter

If
CO

meter
is
not

available
the

following
procedures
may
be
used

L
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

temperature

indicator

points
to
the
middle

Further

keep
engine
running
at
about
2

000

rpm
for
about
5

minutes
without

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

proceed
as

described
in

steps

5
to

9
below

5

Remove
air

hose
between
3

way

connector
5

way
connector

for
Cali

fornia
models
and
air

check
valve

shown
in

Figure
EF

35

Plug
the
dis

connected
hose

19
prevent
dust
from

entering

6
Race

engine
1
500
to
2
000

rpm

two
or

three
times
under

no
load
then

run

engine
for

one
minute

at

idling

speed

7

Adjust
throttle

adjusting
screw
so

that

engine
speeds
are

as
indicated

below

Engine
speed

Manual
transmission

815

rpm

Automatic
transmission

in
D

position

670

rpm

8
Check

ignition
timing
if
neces

sary

adjust
it

to
the
value

required
by

specifications
This

operation
need

not

be
carried
out
at
1

600
km
1

000

miles
service

9
At
about

10
minutes
after

engine
Engine
Fuel

is

run
at

idling

speed
adjust
idle

adjusting
screw
until
maximum

rpm
is

obtained

10

Repeat
procedures
as
described

in

steps
6
7
and

9
above

until

engine

speed
at
best
idle
mixture
is
815

rpm

for

manual
transmission

models
and

670

rpm
for
automatic
transmission

models

in
D

position
Adjustment

in

step
9
can
be
carried
out

right
after

step
7

11
Turn
the

idle

adjusting
screw

clockwise
until

engine
speed
drops
off

below

specified

rpm

Engine
speed

drops
off

Manual
transmission

60
to
70

rpm

Automatic
transmission

in
D

position

15
to
25

rpm

12

Connect
air
hose

to
air

check

valve

If

engine
speed
increases

readjust
it

to
the

specified

speed
with

throttle

adjusting
screw

Idle
limiter

cep

Do
not

remove
this
idle

limiter

cap

unless

necessary
If
this
unit
is
re

moved
it
must

be

readjusted
at
lime

of

installation
To

adjust
proceed
as

follows

I

After

adjusting
throttle

or
idle

speed

adjusting
screw
check

to
be
sure

that
the
amount

of
CO
contained
in

exhaust

gases
meets

the
established

standard

2

Install
idle
limiter

cap
in

position

making
sure
that
the

adjusting
screw

can
rotate
another
1
8

turn
in

the

CO

RICH
direction

Carbo
to

per

CO

rich

450
lIS
rotation

t
CO
lean

J

SQ

dl
lim

ET031
1
e
Iter

cap

Fig
EF

36

Setting
idle
limiter

cap

FUEL

LEVEL

1

Turn

down
float

chamber
to
al

low
float
to

come
into

contact
with

needle

valve
and
measure

Hu
shown

EF
22
in

Figu
re
EF

37

When
H

is

approximalely
7

mill
0
283

in

lOp
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
wi
th

attached

level

gauge

p

j

i

I

it

I
Float
seat

2

Float

3

Float
chamber

4
Needle
valve
t
I
IIf

ET032

Fig
EF
37

Adjusting
float
level

2

Adjust
bottom
float

position
so

that
clearance
h
between

float
seat

and
needle

valve
stemis
I

3
to
L
7

mm

0
051
to
0
067
in
when

Iloat
is

fully

rals
n

Jloa
t

goppe

q
re

3

After

adjustments
in

steps
I
and

2

above
have
been
made

make
sure

that

when
fuel
is

delivered
to
the
float

chamber

the
fuel
level
is
maintained

within
the

range
of23
mm

0
91
in

as

shown
in

FigureEF
38

H
23

mm
0
91
in

EF260

Fig
EF
38

Checking
ruellevel

FAST
IDLE

I
With

carburetor

assembly
reo

moved
from

engine
measure
throttle

valve

clearance
A

with
a

wire

gauge

placing
the

upper
side

of
fast

idling

screw
on
the
first

step
on
fast

idling

cam

When
throttle
valve
is

opened
fur

ther

locking
arm
is
detached
from

secondary
throttle
arm

permitting
see

ondary

system
to

start

operation

Linkage
between

primary
and

see

ondary
throttles
will
function

properly

if
distance

between
throttle
valve
and

inner
wall

of
throttle

chamber
is
74

mm

0
291
in

Adjustment
is
made

by
bending

connecting
link

I

L
l

1

4
CAl

Secondary
prm

ary
I

Jl
I

7
t
@

1
Roller

4

Adjust
plate

2

Connecting
lever

5
Throttle
c
amber

3
Return

plate
6
Throttle
valve

Fig
EF

48

Adjusting
interlock

opening

DASH
POT

1

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

touches

stopper
lever

3

Adjust
position
of

dash

pot
by

turning
nut

until

engine
speed
is
in
the

specified
range

Specified
engine

speed

Manual
transmission

1

900
to
2

100

rpm

Automatic
transmission

1
650
to
1

850

rpm

4

Tighten
lock

nuts

5
Make

sure
that

engine
speed

drops
smoothly
from
2

000
to
1

000

rpm
in

about
three

seconds
Engine
Fuel

Fig
EF
49

Adjusting
dash

pot

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

ANTI

DIESELING

SOLENOID
VALVE

If

engine
does
not

stop
when

igni

tion
switch
is
turned
off

this
indicates

that
a

striking
closed
solenoid

valve

is

shutting
off

supply
of
fuel
to

engine

If
harness
is
in

good
condition

replace
solencid
valve
as
a
unit

Notes

a

Tightening
torque
is
1

8
to
3
5

kg
m
13
to
25

ft
Ib

b

After

replacement
star

engine
and

check
to
be
sure
that
fuel
is
not

leaking
and
that
anti
dieseling

sol

noid
is
in

good
condition
B
C
D
D

CIRCUIT
WITH

FUNCTION
TEST

CONNECTOR

Caution
Do

not
attach
test
leads

of
a

circuit

tester
to
those
other

than

designated
Refer
to

Figure
EF

50

Menuel

trensmlsslon
models

I

Check
for

continuity
between
A

and
B
when

vehicle
is

brought
to
a

complete
stop
Refer
to

Figure
EF

50

B
C
D

D
circuit
is

functioning

properly
if

continuity
exists

and
volt

meter

reading
is

0
volt

d

c
in

step
2

below

If

continuity
does
not
exist

check

for

disconnected
connector
and
or

faulty
amplifier
speed
detecting

switch

or
B
C
D
D
solenoid
valve

2

Check
for

presence
of

voltage

across
A

and
B
at

a

speed
of
more

than
16

km
h

10
MPH
Refer
to

Figure
EF

50

Conduct
this

test

by
one
of
the

following
two

methods

I
Raising
up
rear
axle

housing
with

stand

2
Chassis

dynamometer
test

If
voltmeter

reading
is
0

volt
at
a

speed
of
more
than
16
km
h
10

MPH
circuit
is

functioning
prop

erly

If
voltmeter

reading
is
not
0
volt

check
for
disconnected
connector

burned
fuse

faulty
amplifier

B
C
D
D
solenoid
valve
or

speed

detecting
switch

3
If

by
above
checks

faulty
part
or

unit
is
located
it
should
be

removed

and
tested

again
If

necessary
replace

1

P4
11
0

8

l
1

Ignition
Icey

2

Fuse

3

Amplifier

4

Speed
detecting
switch

Above
10

mph
OFF

Below
10

mph
ON

5

Function
test
connector

6
B

C
D
D

solenoid
valve

EF711

Fig
EF

50

Checking
B
C
D
D
circuit
with

function
test

connector

for
manual
transmission

EF
25

AUtomatic

trailamlsalon
modela

I

With
inhibitor

switch
ON
UN

or
P

position
check
for

presence
of

voltage
across
A
and
B
Refer
to

Figure
EF
51

If
voltmeter

ading
is

12
volts

d
c
B
C
D
O
circuit
is

func

tioning
properly

If
vol
tmeter

ading
is

zero
check

for
disconnected

connector

faulty

solenoid
valve

m
inhibitor

switch

2
With
inhibitor

switch
OFF

HI
2
IY
or
oR

position
Engine
Fuel

check

for
resistance

between
A
and
B

Refer

to

Figure
EF
51

If

ohmmeter

reading
is
25

ohms
or

below
circuit
is

functioning
prop

erly

If

ohmmeter

reading
is
32

ohms
or

above

check
for

poor
connection

of
connec
or

faulty
B
C
D
D
sole

noid
valve
or
inhibitor

relay

3

If

by
above
checks

faulty
part
or

unit
is

located
it

should
be
moved

and

tested

again
If

necessary
replace

yu
@

@
1

Ignition
key

2

Inhibit
T
switch

N
P

positions
ON

I

2
D
R

positions
OFF

3
D

C
D

D
solenoid
valve

4

Function
test
connector

5

Inhibitor

relay

EF712

Fig
EF
51

Checking
B
C

D
D
circuit
with

unction
t
st
connector

for
automatic
transmi
sion

Set

pressure

of

Boost
Controlled

Deceleration
Device
B
C
D
O

Generally
it
is

unnecessary
to
ad

just
the

B
CD
D

however
if

it
should

become

necessary
to

adjust
it
the

procedure
is
3S
follows

Prepare
the

foUowing
tool

I

Tachometer
to

measure
the
en

gine
speed
while

idling
and
a

screw

driver

2
A

vacuum

gauge
and

connecting

pipe

Note
A

quick
response

type
hoost

gauge
such
as
Bourdon
s

type
is

recommended
a

mercury
type

manometer

should
not
be
used

To

properly
set
the

B
C
D

D
set

pressure
proceed
as
follows

I
Remove

the
harness
of
solenoid

valve
To
B
D
D

solenoid
valve

1

B
C
D
D

olenoid

valve

harness

EF262

Fig
EF
52

Removing
harness

of

solenoid
valve

2

Connect
rubber
hose
between

vacuum

gauge
and
intake
manifold

as

shown

Fig
EF
53

Connecting
vacuum

gauge

EF
26
3

Warm

up
the

engine
until
it
is

heated
to

operating
temperature

Then

adjust
the

engine
at
nunnal

idling
setting
Refer
to
the

item

Idling

Adjustmenl
in

page
EF

21

Idling

engine
speed

Manual
transmission

750

rpm

Automatic
transmission

in
D

position

650

rpm

4

Run
the

engine
under
no

load

Increase

engine
speed
to
3
000
to

3
500

rpm
then

quickly
close
throttle

valve

5
At
the
time
the
manifold
vacuum

p
ssure
increases

abruptly
to

600

mmHg
23

62

inHg
or
above

and

then

graduaUy
decreases
to
the
level

set
at

idling

6
Check
that
the
B
C
D
D
set

pres

sure
is
within
the

specified
pressure

Specified

pressure
0
m
sea
level

and

760

mmHg
30

inHg
atmos

pheric

pressu

Manual
transmission

510

to
550

mmHg

20
1

to

21
7

inHg

Automatic
transmission

490
to

530

mmHg

19Tto
20

9

inHg

Notes

a
When

atmospheric
pressure
is

known

operating
pressure
will

be

found

by
tracing
the

arrow
line

A

See

Figure
EF
56

When
alti

tude
is
known

operating
pressure

will

be
found

by
tracing
the
arrow

line
B

See

Figu
EF
56

b

When

checking
the
set

pressu
of

B

CD
D
find
the

specified
set

pressu
in

Figure
EF

56
from
the

atmospheric
pressure
and
altitude

of

the

given
location

For

example
if

an
automatic
trans

mission
model
vehicle

is
located
at

an
altitude
of
1

000

m
3

280
ft

the

specified
set

p
ssu

for

B
C
D
D
is
445

mmHg
17

5

inHg

7
If
it
is

higher
than

the
set
level

turn
the

adjusting
screw
or
nut
until

correct

adjustment
is

made

Engine
Fuel

DISASSEMBLY
AND
ASSEMBLY

ff

C
oI

Q

f

@

ID
J

@
tJ

@
1
Lock
lever

2
Filter

set
screw

3

Fuel
filter

4
Fuel

nipple

5
Needle
valve

body

6
Needle
valve

7
Fuel

chamber

parts

8

Accelerating

pump
parts

9
Altitude

compensator
pipe

California
models

tng
ail

bleed

adJ

@

@1

@
A

Choke

chamber

B

Center

body

C
Throttle

chamber

I

J

@

EF725

EF30
11

High
speed
enricher
air
bleed

12
Choke

valve

13

Accelerating
pump
lever

14

Throttle
return

spring

15

Accelerating
pump
rod

16

Automatic

choke
cover

17
Automatic
choke

body
and

diaphragm
chamber

18
Richer

jet

19

Coasting
air
bleed
I

20

Primary
main

jet

21

Secondary
main

jet

22

Secondary
slow

air
bleed

23

Secondary
slow

jet

24

Plug

25
Air

bleed

26

Coasting
jet

27

Secondary
main
air

bleed

28
Power
valve

29

Primary
main
air

bleed

30

Plug

31

Primary
slow

jet

32
No
2

primary
slow

air
bleed

33

Primary
and

secondary
small

venturi

34
Venturi

stopper
screw

35
Choke

connecting
rod

36
Anti
dieseling

solenoid
valve

37
Fast

idle
cam

38

Diaphragm
chamber

parts

39
Idle

limiter

cap

40
Idle

adjust
screw

41
Idle

adjust
screw

spring

42
Throttle

adjust
screw

3

Thr9ttle

dj
t
5Crew

spring

44

Primary
and

secondary
throttle

valve

45

B
C
D
D

California

models

46
Vacuum

control
solenoid
valve

47
B
C

D
D
Non
Califomia

models

Note

Do
not
remove
the

parts

marked

with
an
asterisk

Ill

@ff

Fig
EF

62
Carburetor

part

Engine
Fuel

SERVICE
DATA
AND
SPECIFICATIONS

Airclelllcr

Ail
control
val

partially

opem

Air
ntrol
valve

fuUy
opens

Idle

ompensatoI

partially
opens

Hi
mettiNo

l

Bi
metal
No
2

Idle

ompen
tor

fully
opens

Bi
metal

No
1

Hi
metd
No
2

Fuels
Stem

Fuel

prtuure

Fuel

pump
apacHy

C
rbu
tor

C
rbu
tor

type

Carburetor
model
Oc

oF

oCe
F

oCe
F

Oc
OF

kpJcm2
poi

US

pt
min
at

rpm

Outlet
diameter

Venturi
diameter

Main

jet

Main
air
bleed

Slow

jet

Power
val

Float
level
U

fuel

preuure
rom
in

mm
in

mm

in

kg
cm2

psi

Adjustment

Engine
idling
Ignition
timing
Idle

speed
CO
at

mloro

Fuel
level

adjustment

Gap
between
Ive
stem
and
noat
at
mm

in

H

H

h

Fast
idle

adjwtmcnt
Fast
idle
earn

tint

step

Gap
between
throttle
IYe
and
carburetor

body

mm
in

Vacuum
break

adjustment

Gap
between
choke
alve
and
carburetor

body

mm

in

Choke
unloadel

adjusttncnt

Gap
between
choke
alw
and
carburetor

body

rom
in

Bi

metalsettinl

Bi
metal
resistance
at
2Ioe
700F

n

Bi
metalsettina

lnterloc
k

opcnina
of

primary
and

secondary

throtUc
valves
mmOn

Duh
pot

adjustment
without
loadin

I
m

Anti
diclClinasolenoid
valV
C

tiahtenina
torque

ka
m

in
lb

a
c
D
D
set

p
JSure

0
m
sea

level
and
760

mmHg

30
inlla
atmospheric
pressure
J
mmHa
inHg

R
C
D
D

tiahteninl
torque
kg
m

n
b
Nl
n
California
modell

Manual
transmiSsion

I
Automatic
transmission
California
modeb

Manual
transmission

I
Automatic
transmission

30
to
54
86
to
129

above

55
131
30
to
54
86
to
129

above
55

131

60
to
70

140
to
158

70
to
90

158
to
194
60
to
70

140
to
158

70
to
90

158
to
194

above
70

158

above
90

194
above
70

158

above
90

194

0
21
to
0
27
2
99
to
3
84

t
OOO

2
i
I
OOO
0
21
to
0
27
2
99
to

3
84

1
000
2
i
I
OOO

Strombcra
type

OCH340
7A
DCH340
48A
Stromt
rg

type

DCH34Q
45B
DCH340
46A

Primary
Secondary
Primary
Secondary
Primary
Secondary
Primary
Secondary

30
I8t

340
339
30
1
181
34
1
339
30
1
181

34
1
339
30
1

181
34
1
339

24
0
945

310
220
24
0
945
31
1
220
24
0
945
31
1
220
24
0
945
31
1
220

199
1160
199
1160
1101
1160
101

1160

170
160
170
160
170
60

170
1
60

148
1100
148
1100
148
1100
148
180

143
143
140
140

23
0
906
23
0
906
23
0
906
23

0
906

0
17
2
408
0
17
2
40B
0
17
2
408
0
17
2
408

1201750

rpm
CO

2
1
120

650

rpm
0

100
750rpm
C02
t
1
120
650

rpm
0

position
CO

2
t
1

position
CO
2
t
1

7
2

0
283
7
2
0
283
7
2
0
283
7
2
0
283

23
0
906
23

0
906
23
0
906
23
0
906

1
3
to
1
7
1

3
to

1
7
1
3
to

1
7
1
3
to
1
7

0
051
to
0
067
0
051
to
0

067
0
051
to
0
067
0
051
to
0
067

1
33
to
1
47
1
58
to
1
72
1
33
to

1
47
1
58
to
1
72

0
0524
to
0
0579
0
0622
to

0
0677
0
0524
to
0
0579
0
0622

to
0
0677

1
42
0
056
1
42
0
056
1
42
0
056
1
5
0
059

2
45
0
096
2
45
0
096
2
4
0
096
2
45
0
096

3
7
to

8
9
3
7
to
8
9
3
7
to
B
9
3
7
to
8
9

Center
of
the
ndex
mark
Center
of
the
index
mark

7
38
0
291
7
38
0

291
7
38
0

290
7
38
0
291

1
900
to

2
100
1
650
to

1
850
1
900
to
2
100
1
650
to

1
850

180
to
350

156
to
304
180
to
350

156
to
304
180
to
350

156
to

304
180
to
350

156
to
304

510
to

550
490
to

530
510
to
550
490
to
530

20
1
to
21
7
19
3
to

20
9
20
1
to
21
7
19
3

to
20
9

20
to
40

17
4
to
34
1
20

to
40

11
4
to
34
7
20
to
40

17
4
to
34
7
20
to

40
17
4
to
34
1

EF
35

Engine
Fuel

toms
and

causes
of
carburetor
troubles

and

remedies
for
them

are
listed
to

facilitate

quick
repairs

There
are
various
causes
of

engine

malfunctions
It
sometimes

happens

that
a
carburetor
which
has
no
fault
TROUBLE

DIAGNOSES
AND

CORRECTIONS

In
the

following
table
the

syml

Condition

Probable
cause

Overflow
Dirt
accumulated
on

needle
valve

Fuel

pump
pressure
too

high

Needle
valve

improperly
seated

Excessive
fuel

consumption
Fuel
overflow

Slow

jet
too

large
on
each
main

jet

Main
air
bleed

clogged

Choke
valve
does
not

open

fully

Outlet
valve
seat
of
accelerator

pump

improper

Linked

opening
of

secondary
throttle
valve

opens
too

early

Power

shortage
Main

jets
clogged

Every
throttle
valve
does
not

open
fully

Idling

adjustment
incorrect

FIICI
tr

clogged

Vacuum

jet

clogged

Air

c1eane

clogged

Diaphragm
damaged

Power
valve

operating
improperly

Altitude

compensator
setting
incorrect
Cali

fornia

models

Improper
idling
Slow

jet
clogged

Every
throttle

valve
does
not
close

Secondary
throttle
valve

operating
im

properly

Throttle
valve

shafts
worn

Packing
between

manifold
carburetor

fauJiy

Manifold
carburetor

tightening
improper

Fuel
overflow

B

C
D
D

adjustment
incorrect

Vacuum
control
solenoid

damaged

Stuck
anti
stall
dash

pot

EF

36
appears
to
have

some

problems
when

actually
the

electric

system
is
at
fault

Therefore
whenever

the

engine
is

mal

functioning
the
electrical

system

should
be
checked
rust
before

adjust

ing
carburetor

Corrective
action

Clean
needle
valve

Repair
pump

Re

place

See
condition
overflow

Replace

Clean

Adjust

Lap

Adjust

Clean

Adjust

AdjusL

pa
ir

Clean

Clean

Replace

Adjust

Correct
H
L
lever

position

Clean

Adjust

Overhaul
and

clean

Replace

Replace
packing

Correct

tightening

See
l
ondition
ov

rl1ow

Adjust

Replace

Replace