engine DATSUN B110 1973 Service Repair Manual

ENGINE

When
the

engine
is

operating
under

heavy
load
the

air
control
valve

fully
opens
the
underhood
air

inlet
to

obtain
full

power
regardless
of
the

temperature
around

sensor

TEMPERATURE
SENSOR

Removal
and

installation

Removal

Hatten
the

tabs
of

clip
with

pliers

2
Pull
out
hoses

Note
Note
the

respective
positions
of
the
hoses
from

which

they
were
removed

3

Pry
the

tab
of

clip
with
a
screwdriver

4
Take

off
the
sensor
and

clip

I

@

f
6

7

CID

f

j
EC019

1

Pipe

2
Catch

3
Fixed
with
adhesive

4
Hose

5
Tab

6

Clip

7

Gasket
rubber

Fig
EF
6

Removing
sensor

Installation

I
Install
the

sensor
and

gasket
assembly
in
the

proper

positions

EC020

Fig
EF
7

Installing
sensor
This
control

of
carburetor
air

temperatures
allows

leaner
carburetor

calibration
with

accompanying
reduced

emissions
than

conventional
controls
and

also
eliminates

carburetor

icing

2
Insert

clip
Be

sure
to
hold
the

sensor
at
the

portion

A
in

Figure
EF
7
to
avoid

damage

Press
fit
the

clips
into
the

pipe
while

straightening
the

tabs

Note
Use

care
not
to

damage
the
sensor

EC021

Fig
EF
B

InseTting
clip

3
COIUlect
the
hoses
to
their

proper
positions

EC022

Fig
EF
9

Connecting
hoses

EF
4

FUEl
SYSTEM

FUEL
STRAINER

DESCRIPTION

The

fuel
strainer
is
of
a

cartridge
type
It

uses

paper

element
as
strainer
element
which
can
be

checked
for

condition

from
outside
This
strainer
cannot
be
cleaned

Replace
the
strainer
at
the

specified
service
interval
or
if
it

becomes

clogged
or

restricted
REMOVAL

Disconnect
inlet
and
outlet

fuel
lines
from
fuel

strainer
and

remove
fuel
strainer

Note
Before

disconnecting
fuel
lines
use
a
container
to

receive
the

remaining
fuel
in
lines

r

@
I

I

Il
QY
I

I
I
elementl
3
Cover
@

EF005

Fig
EF
10
Sectional
view

of
caTtridge
type
fuel
stTaineT

FUEL
PUMP

CONTENTS

DESCRIPTION

FUEL
PUMP

TESTING

Static

pressure
test

Capacity
test
EF
5

EF
6

EF
6

EF
6

DESCRIPTION

The
fuel

pump
transfers

gasoline
from
the
tank
to
the

carburetor
in
sufficient

quantity
to
meet

engine
require

ments
at

any

speed
or
load

The
fuel

pump
is
of
the

diaphragm
type
REMOVAL
AND
DISASSEMBLY

INSPECTION

ASSEMBLY
EF
7

EF
B

EF
B

The
fuel

pump
consists
of
a

body
rocker

arm
and
link

assembly
fuel

diaphragm
fuel

diaphragm

spring
seal

inlet
and
outlet
valves

The
fuel

diaphragm
consists
of

specially
treated
rubber

which
is

not
affected

by
gasoline
held

together
with
two

metal
discs

and
a

pull
rod

EF
5

ENGINE

FUEL
PUMP

TESTING

A
fuel

pump
is

operating
properly
when
its

pressure
is

within

specifications
and
its

capacity
is

equal
to
the

engine
5

requirements
at
all

speeds
Pressure
and

cap
lcity
must
be

determined

by
two
tests

with

the

pump
mounted
on
the

engine
Be

sure
that

there

is

gasoline
in
the

tank
when

conducting
these

tests

Fig
EF
11
Schematic
view

of
fuel
pump

Static

pressure
test

The

static

pressure
test
is

conducted
as
follows

Disconnect
the
carburetor
fuel
line
at

the
carburetor

2
Install
the

necessary
adapter
and
tee

fitting
to
the

fuel
line

and
attach
a

suitable

pressure
gauge

Start
and
run

engine
at

varying
speeds

4

The

reading
on
the

gauge
is
the

static
fuel

pressure

and
this
should
remain
within
the

following
limits

0
18

kgJcm2
2

61b

sq
in

Pressure
below
the
lower
limit

indicates
extreme
wear

on
one

part
or
a
small
amount
of
wear

on
each

working

part

They
also
indicate
a

ruptured
diaphragm
worn

warped
dirty
or

gumming
valves

and
seats
or
weak
diaphragm
return

spring
Pressure
above
the

upper
limit

indicates
an

excessively
strong

diaphragm
that
is

too

tight

This
condition

requires
removal

of
the
fuel

pump
as

sembly
for

replacement
or

repair

Capacity
test

The

capacity
test

is
used

only
when
the
static

pressure

is
within

specifications
The

capacity
test
is
conducted
as

follows

1
Disconnect
the

fuel

pipe
at

the
carburetor

2

Place
a
suitable
container
at

the
end

of
the

pipe

3

Start
the

engine
and
run
at
1

000

rpm

4

The

pump
should
deliver
450
cc
I
V
S

p
of
fuel
in

one
minute

or
less

EF
6

ENGINE

INSPECTION

Check

the

upper
and
lower
bodies
for
cracks

2

Check
the
valve

assembly
for

wear
of
the
valve
and

valve

spring
Blow
the
valve

assembly
by
breath
to

examine
its

function

3

Check
the

diaphragm
for
small
holes
cracks

and

wear

4

Check
the
rocker

arm
for
wear
at
the

portion
in

contact
with

the
camshaft

5

Check
the
rocker
arm

pin
for
wear
since
a
worn

pin

may
cause
oil

leakage

6

Check
all
other

components
for

any
abnormalities

and

replace
with
new

parts
as

required
ASSEMBLY

Assembly
is
done
in
reverse
order
of

disassembly
For

reassembly
and

reinstallation
the

following
matters

should
be
noted

Use
new

gasket

2
Lubricate
the
rocker
arm

link
rocker
arm

pin
and

lever

pin
before
installation

3
To

test
the
function

position
the

fuel

pump
assem

bly
about
I

meter
3
3
ft
above
fuel
level
with
a

pipe

connecting
the
fuel

pump
and
the
fuel

strainer
and

operate
the
rocker

afm

by
hand
If
fuel
is
drawn

up
soon

after
the
rocker
arm
is
released

the
function
of
the

pump

is

satisfactory

CARBURETOR

CONTENTS

DESCRIPTION

STRUCTURE
AND
OPERATION
EF

8

EF

9

EF
10

EF
11

EF
12

EF
12

EF
12

EF
14

EF
14

EF
15

EF
15

EF
16

EF

16
Primary
system

Secondary
system

Anti

dieseling
solenoid
valve

Float

system

Electric
automatic
choke

ADJUSTMENT

Idling
adjustment

Fuel
level

adjustment

Fast
idle

adjustment

Vacuum
break

adjustment

Choke
un
loader

adjustment

DESCRIPTION

The
carburetors
are

of
a

downdraft

type
which
is

designed
and
built

to
increase

power
and

fuel

economy
as
Bi
metal

setting

Adjustment
of

interlock

opening
of

primary
and

secondary
throttle
valves

Dash

pot
adjustment

MAJOR
SERVICE
OPERATIONS

Removal

Disassembly

Cleaning
and

inspection

Assembly
and
installation

JETS

SERVICE
DATA
AND
SPECIFICATIONS

TROUBLE
DIAGNOSES
AND

CORRECTIONS
EF
17

EF
18

EF
18

EF
19

EF
19

EF
19

EF
21

EF
22

EF
22

EF
22

EF
22

well
as
to
reduce
the

emission
of
exhaust

gases

These
carburetors

present
several
distinct
features
of

importance
to
the

car
owners

A

summary
of
features
is
as
follows

EF
8

FUEl
SYSTEM

Secondary
throttle
valve

is

operated
by
throttle
lever

The

high

power
and

good
acceleration
are

gained
with

combination
of

the

auxiliary
valve

2

Accelerating
pump
gives
excellent

acceleration

3

The

power
valve
mechanism
is
of
a

vacuum
actuated

boost

type
and

improves

high
speed
driving

4
The

throttle

opener
control

system
Refer
to
Section

ET

incorporates
a

servo

diaphragm
The
servo
dia

phragm
helps
open
the
throttle

valve
at
a

decreasing
speed

so
as

to
reduce

the
emission
of

hydrocarbons
to
a

minimum

5
An

anti
dieseling
solenoid

is
used
as
a

means
of

preventing
dieseling
When
the

ignition
key
is
turned
off
the
fuel

passage
involved
in
the
slow

system
is

closed

and
the
fuel

supply
is
shut

down

completely

6
In

the
choke

mechanism
an

electric
automatic

choke

is
used
to

automatically
control
the
choke
valve

operation

during
the
warm

up
of
the

engine

7
The
carburetor

for
automatic
transmission
is

equipped
with
so
called

dash

pot
that

is
it
makes
smooth

decelerating
without

engine
stall
at

any

operating
condi

tion

These

carburetors
are

quite
similar
in

appearance
as

explained
above

except
the

dash

pot
for
the
au
tomatic

transmission
model
The

differences
in

performance
are

explained
in
the

following
as

necessary

for
Manual
transmission

for
4utomatic
transmission

Fig
EF
14
External
view

of
carburetor

STRUCTURE
AND
OPERATION

These

carburetors
consist
of

the

primary
system
for

normal

running
and

secondary
system
for
full

load

running
The

float

system
which
is

commonly
used

by
the
primary
and

secondary
systems
the

secondary
switch
over

mechanism

accelerating
mechanism
etc
are

also
at

tached

The
anti

dieseling
solenoid
valve
and
the

power
valve

mechanism

are
used

The

carburetor
is
of
down
draft
two
barrel

type

EF
9

ENGINE

6

f

I

Filter

to

Primary
main
nozzk
18

Secondary
throttle
valve

2
Needle
valve
11

Primary
main
air
bleed

19

Primal
throttle
valve

3

Secondary
slow

jet
12

Primary
slow
air
bleed
20
Idle
nozzle

4

Secondary
slow
air
bleed
13

Primary
slow

jet
2t

By
pass
hole

5

Secondary
main
air
bleed
14
Float
22

Primary
main

jet

6

Secondary
main
nozzle
15

Secondary
emulsion
tube
23

Primary
emulsion
tube

7

Secondary
air

vent

pipe
t6
Secondary
main

jet
24

Power
valve

8
Choke
valve
t7

Auxiliary
alve
25
Level

gauge

9

Primary
air
nt

pipe

Fig
EF
15
Sectional
view

of
model
DCH306
carburetor

bleed
The

gas
mixture
is

injected
into
the
venturi

through
the
main
nozzle

When
the

throttle
valve
is
wide

open
and
the

engine

requires
dense
mixture

gas
the

power
valve

opens

from
where
the
fuel
also
flows
into
the
main

system
Primary
system

Primary
main

system

The
fuel

flowing
out
of
the

passages
at
the

bottom
of

the

float
chamber

passes
through
the

primary
main

jet

and
is
mixed
with

the
air

coming
from
the
main
air

Secondary
side

Primary
side

1

Primary
main
nozzle

2

Primary
main
air
bleed

3
Primary
slow
air
bleed

4

Primary
slow

jet

5
Secondary
throttle
valve
6
Primary
throttle
valve

7
Idle
nozzle

8

By
pass
hole

9
Primary
main

jet

Fig
EF
16

PaTtially
loading

EF
10

FUEl

SYSTEM

Idling
and
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

Accelerating
mechanism

Cj

f

li

Ip

j

1

2

3

4
5
Inlet
valve

6
Outlet
valve

7
Primary
throttle
valve

8

Pump
connecting
rod
Pump
lever

Pump
nozzle

Piston

Piston
return

spring

Fig
EF
17

Accelerating
mechanism

A

mechanical
accelerating

pump
synchronized
with
the

throttle
valve
is
used

When
the
throttle
valve

is
closed
the

piston
rod
is

pushed
up
with
the

linkage
which

pushes
up
the

piston

through
the

piston
return

spring

When
the

piston
comes
down

the
inlet
valve
closes
the

outlet
valve

opens
and
the

fuel
within
the

pump
is

blown
out
from

the

pump
jet
by
the

compressed
piston

return

spring
The

fuel
hits

against
the
side
wall
of
the

small
venturi

becoming
minute

drops
and

compen

sating
trancient

sparseness
of
the

fuel

Power
valve
mechanism

The

power
valve
mechanism
so

called
vacuum
actuated

boost

type
makes
use
of
the
downward

pulling
force

of
the

air
stream
below
the

throttle
valve

When

the
throttle
valve
is

slightly
opened
during
light

load

running
a

high
vacuum
is
created

This
vacuum

pulls
the
vacuum

piston
upward
against

the

spring
leaving
the

power
valve
closed

When
the

vacuum
is

lowered

during
full

load
or

accelerating
running
the

spring
pushes
the
vacuum

piston
downward

opening
the

power
valve
to
furnish

fuel

EF
11
Secondary
system

Secondary
main

system

When
the

primary
throttle
valve
is
wide

open
and
the

engine
produces
high
power
the

secondary
throttle

valve

begins
to

open
by
the

linkage

However
the

auxiliary
Y
J

lve
does

not

open
at
a
slow

speed
due
to
the

counterweight
connected
to
the
valve

shaft

As
the

engine
picks
up

speeds
the

auxiliary
valve

opens

against
the

load
of
the

counterweight
and
the
second

ary
system
starts

operation
for

high
power
operation

The
fuel

flowing
out
of
the

passage
at
the
bottom
of

the
float

chamber

passes
through
the

secondary
main

jet
The
fuel
is
mixed

with
the
air

coming
from
the

main
air

bleed
and
the
mixture
is
blown
into
the

venturi

through
the
main
nozzle

When
the

primary
throttle
valve
is
in
the
full

open

position
the

secondary
throttle
valve
is
also

fully

opened

t

2

3

4
5

Auxiliary
valve

6
Secondary
throttle
valve

7

Primary
throttle
valve

8

Primary
main

jet
Counter
lever

Primary
main
nozzle

Primary
main
air
bleed

Counterweight

Fig
EF
1B
At

full
open
slow

speed

j

1

2

3

4

5

6
Counter

weight
7

Secondary
main
air
bleed
8

Secondary
main
nozzle
9

Counter
lever
10

Primary
main
nozzle
11

Primary
main
air

bleed
Secondary
main
jet

Auxiliary
valve

Secondary
throttle
valve

Primary
throttle
valve

Primary
main

jet

Fig
EF
19
At

full
open
high
speed

ENGINE

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

step
port
is

located

near
the

auxiliary
valve
in
its

fully
closed

state

Anti

uesetmg

solenoid

Ignition
switch

OFF
ON

I

L
i1

7

I
Anti

dieseling
solenoid

valve

When
the

ignition
key
is
turn

to
OFF

current
will

not
flow

through
the

solenoid
and
the
slow

system
fuel

passage
is

closed
to
shut
down

the

engine
without

dieseling

If
anti

dieseling
solenoid
is
found

defective

replace
the

solenoid
as
an

assembled
llnit

Fuse

Ignition
switch

T
Baitery

717

Fig
EF
20
Schematic

drawing
of
anti

dieseling
solenoid

Removal
and

installation
of
anti
dieseling
solenoid

Removal

Solenoid
is

cemented
at

factory
Use

special
tool

STl9
I

50000
to

remove
a

solenoid

When

this
tool
is

not
effective
use
a

pair
of

pliers
to

loosen

body
out
of

position

Installation

I

Before

installing
a
solenoid
it
is
essential

to
clean
all

threaded

parts
of

carburetor
and
solenoid

Supply

screws
in
holes

and
turn
them
in

two
or
three

pitches

2

First
without

disturbing
the

above

setting
coat

all

exposed
threads
with
adhensive
the
Stud
Lock
of

LOCTlTE
or

equivalent

Then

torque
screws
to
35
to
55

kg
cm
30
to
48

in
lb

using
a

special
tool
STl9150000

After

installing
anti

dieseling
solenoid
leave

the

carburetor

move
than
12
hours
without

operation

3
Mter

replacement
is

over
start

engine
and
check
to

be

sure
that
fuel
is
not

leaking
and
that
anti

dieseling
solenoid
is
in

good
condition
Notes
a
Do
not
allow
adhesive

getting
on
valve

Failure
to
follow
this
caution
would
result
in

improper
valve

performance
or

clogged
fuel

passage

b

In

installing
valve
use
caution
not
to
hold

body
directly
Instead

use
special
tool

tight

ening
nuts

as

required

Float

system

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

As
ventilation
within
the
float

chamber
is
of
an

air
vent

method

Electric
automatic
choke

An
electric
heater

warms
a

bimetal
interconnected
to

the
choke
valve
and
controls
the

position
of
choke
valve

and
throttle
valve
in
accordance
with
the

elapse
of
time

or

the
warm

up
condition
of

engine

The
construction
and
function
of
each

part
of
this

automatic

choke
are

as
follows
See

Figure
EF
21

EF
12

FUEl

SYSTEM

l

I

@

1J
w

I

I

I

I

1

1
1
t

2

3

4

5

6

7

8

9

10

tt

12
Hi
metal

Heater

Bi
metal

cover

Fast
idle

earn

Bi

metal

Bi

metal

index
mark

Choke

shaft
lever

Choke
valve

Unloader

tang

Vacuum

diaphragm

Throttle
valve

Fast
idle

adjusting
screw
j

@

Fig
EP
21

Construction

of
electric

automatic
choke

Bi

metal
and
heater

Electric
current
flows

through
the
heater

as
the

engine

starts
and
warms
bi

metal
See

Figure
EF
22
The

deflection
of
bi
metal
is
transmitted
to
the

choke
valve

through
the
choke
valve
lever

Ignition
switch
Fuse

Alternator

T

o

o
Auto
choke
relay

Auto

choke
heater

Fig
EF
22
Schematic

drawing
of
electric

automatic
choke
heater

Fast

idle
C3m

The
fast
idle
cam
determines
the

opening
of
throttle

valve

so
as

to
obtain

proper
amount
of
mixture

corresponding
to
the

opening
of
the

choke
valve
which

depends

upon
the
warmed

up
condition
of
the

enigne
Fast
idle

adjusting
screw

This

screw

adjusts
the

opening
of

the
throttle
valve

by

fast
idle

cam

Unloader

When

accelerating
the

car

during
the
warm

up
period

that

is
before
the
choke
valve
does
not

sufficiently

open
this
unloader
makes
the

choke
valve

open
to
a

certain
extent

so
as
to
obtain
an

adequate
air

fuel

mixture

Vacuum

diaphragm

The

moment
when

engine
starts
this

diaphragm
forces

choke
valve

open
to
the

predetermined
extent
so
as

to

provide
necessary
amount
of
air

fuel
mixture

Bi

metaI
index
mark

The
bi

metal
index
mark

is
used
for

setting
the

moment
of
the

bi
metal
which
controls
the

mixing

ratio

required
for

starting
the

engine

EF
13

ENGINE

AD
JUSTMENT

Idling
adjustment

Idle

mixture

adjustment
requires
the

use
of
a
CO

meter
When

preparing
to

adjust
idle
mixture
it
is

essential
to
have
the

meter

thoroughly
warmed
and

calibrated

Warm

up
the

engine
sufficiently

2
Continue

engine
operation
for
one
minute
under

idling
speed

3

Adjust
throttle

adjusting
screw
so
that

engine
speed

is
800

rpm
in
N

position
for

automatic
transmission

4
Check

ignition

timing
if

necessary
adjust
it
to

the

specifications

Ignition
timing
50
800

rpm

5

Adjust
idle

adjusting
screw
so
that
ca

percentage
is

1
5
t
0
5

6

Repeat
the

adjustments
as

described
in

steps
3

and

5

above
so
that
ca

percentage
is
1
5

to
5
at
800

rpm

Cautions
a
On
automatic
transmission

equipped

model
check
must
be
done
in
the
0

position
Be
sure
to

apply
parking
brake
and

to
lock
both
front
and

rear
wheels
with
wheel

chocks

b
Hold
brake

pedal
while

stepping
down

on

accelerator

pedal
Otherwise
car
will
rush
out

dangerously

7
On
automatic
transmission

equipped
model
make

sure
that
the

adjustment
has
been
made

with
the
selector

lever
in
N

position

And
then
check
the

specifications
with

the
lever
in

D

position
Insure
that
CO

percent
and
idle

speed
are
as

follows

Idle

rpm
650

ca

percentage

with

lever
in
D

position
15
to
5

If

necessary
adjust
by

progressively
turning
throttle

adjusting
screw
and
idle

adjusting
screw
until
correct

adjustments
are

made

Notes
a
Do
not

attempt
to
screw
down
the
id
Ie

adjusting
screw

completely
to
avoid

damage
to
the

EF
14
tip
which
will
tend
to
cause
malfunctions

b
After
idle

adjustment
has
been
made
shift
the

lever
to
N
or
p

position
for
automatic

transmission

c

Remove
wheel
chocks
before

starting
the
car

Throttle

adjusting

screw

2
Idle

adjust

ing
crew

3
Idle
limiter

cap

4

Stopp
r

Fig
EF
23
Throttle

adjusting
screw
and
idle

adjusting

screw

Idle
limiter

cap

Do
not
remove
this

idle
limiter

cap
unless

necessary

If
this
unit
is

removed
it
is

necessary
to

fe

adjust
it
at

the
time

of
installation
To

adjust
proceed
as
follows

1
Make
sure
that
the

percentage
of

CO
contents

satisfies
the

specifications

2

Install
idle
limiter

cap
in

position
making
sure
that

the

adjusting
screw

can
further
turn
3

8
rotation
in
the

Ca
RICH
direction

j
j
Carburetor

stopper

o

u

o

i

r
3
8
rotation

0

0

Idle
limiter

cap

0
0

CO
lean

Fig
EF
24

Setting
idle
limite

cap