engine DATSUN B110 1973 Service Repair Manual

CD

r
Fuel
level

adjustment

@

@

It
I
Float

2

Float
seat
FUEL
SYSTEM

2

Adjust
bottom
float

position
so
that

clearance
h

between

the
float
seat
and
the
needle
valve

stem
is
1

3
to

1
7

mm
0
0512

to
0
0669

in
when
the

float
is

fully

raised
Bend
the

float

stopper

properly
as

required

l

lH

H

ld

up

@

h
Fast
idle

adjustment

Remove
the
bi
metal
cover

3

I
Float

stopper

4
Needle
valve
2
Place
the

fast
idle

arm
on
the
second

step
of

the
fast

idle
earn
Then

adjust
the
fast

idle

adjusting
screw
in
such

a

way
that
the
clearance
of

the
throttle
valve

shown

at

A

in
the
illustration
will
be

the

specifications
See

Figure
EF
26

Fig
EF
25

Adjsuting
float
level

Turn

down
the
float

chamber
to
allow
the
float

coming
into

contact
with
the
needle
valve
and

measure

H
shown
in

Figure
EF
25
When
the
H
is

approxi

mately
19
0
mm

0
748
in

top
float

position
is

correct

The

top
float

position
can
be

adjusted
by
bending
float

seat

Upon
completion
of
the

adjustment
check
fuel
level

with
the

atta
led
level

gauge
Clearance
of
throttle

Engine
revolution

valve
A

mm
in

rpm

Manual
0
80
to

0
88

transmission
0
0315
to
0

0346
1
750

to
2
050

Automatic
1
07
to

l
l
7

transmission
0
0421

to
0

0461
2

650

to
2

950

Fast
idle
earn

steps

5
C

0
J
t

E

r

L

E
I
I

Ogc
l

0

0

JO
A

Throttle
chamber

Fig
EF
26

Adjusting
fast
idle

EF
15

ENGINE

Vacuum
break

adjustment

I

Completely
close
the
chuke
valve

2
Hold
the
choke
valve

by
stretching
the
rubber
band

between
hoke

shaft
lever
and
the
sta

tionary

part
of

carburetor

3

Grip
the

vacuum
break
stem
with

pliers
and

pull

straight
fully

Vacuum
break
rod

Vacuum
break
stew

Rubber
band
4
Under
this

condition

adjust
the

gap
shown

at
B

in
the

illustration
between
the
choke

valve
and

carbure

tor

body
to
1
140
to
1
260
mm

0
0449
to
0
0496
in
for

manual
transmission
car

and
1

205
to
1
335
mm
0
047

to
0
053
in
for
automatic
transmission

car

by
bending

vacuum
break
rod

I

Fig
EF
27

Adjusting
vacuum
break

Choke
un
loader

adjustment

I

Completely
close
the
choke
valve

2
Hold
the
choke
valve

by
stretching
a
rubber

ring

between
the
choke
shaft
lever
and
the

stationary

part
of

the
carburetor

3

Open
the
throttle
lever

until
it

fully
opens

4

Under
this
condition

adjust
the

clearance
C
in
the
illustration
between
the
choke

valve
and
the
carburetor

body
to
2
01

mm
0
079
in

by
bending
unloader

tongue

See

Figure
EF

28

Note
Make
sure
that
the
throttle
valve

fully
opens
when

the
carburetor
is
mounted
on
the
car
If
the

throttle
valve
fails
to

fully

open
the
unloader

becomes

inoperative
resulting
in

poor
acceleration

after
the

engine
is
started

EF
16

ENGINE

Adjustment
of
interlock

opening
of

primary
and

secondary
throttle
valves
Open
the

primary
side
throttle
valve

480
from

the

fully
closed

position
and

measure
clearance
G
1
be

tween
the

throttle
valve

and
throttle
chamber

inside

wall

as
shown
in

Figure
EF
30

@I

30
rom
1
181
in
dia
Gl
5

8

mm
0
228
in

I

V
2
Without

disturbing
the
above

setting
bend

con

necting
rod

as

necessary
so
that

secondary
throttle

valve
is

about
to

open
Upon

completion
of

the

adjustment
make

sure
that
the
link

system
operates
smoothly

2
Dash

pot
adjustment

Automatic
transmission

car

only

It

is

necessary
that
the

idling
speed
of

engine
and

mixture

have
been

weB
turned

up
and

engine
is
sufficient

Iywarm

2
Turn

throttle
valve

by
hand
and
read

engine
speed

when
the
dash

pot

just
touches
the

stopper
lever

1

Connecting
rod

2

Secondary
connecting

lever

3

Throttle
lever
4

Secondary
throttle

valve

5

Primuy
throttle
valve

6
Throttle

chamber
3

Adjust
the

position
of
the

dash

pot
by

turning
the

nut
until
the

engine
speed
is
in
the

range
from
1

900
to

2
000

rpm

Fig
EF
30

Adjusting
interlock

opening

Primary
and

secondary
throttle
valves
4
Make

sure
that

the

engine
speed
is

smoothly
reduced

from
3
000
to
1
000

rpm
within
a

few
seconds

Fig
EF
1

Adjsuting
dash

pot

EF
18

FUEl

SYSTEM

MA
JOR
SERVICE
OPERATIONS

A

completely
adjusted
and
serviced
carburetor
will

provide
the

engine
with

proper
mixture

at
all

speeds

Periodical

overhauling
which
cleans

all

components
and

passages
will

recover
the

originally
designed
performance

producing
the

engine
with

proper
gasoline
and
air
ratio
at

all

speeds
Passages
and
holes
of
the
carburetor
must
be

cleaned

carefully
Use

only
carburetor
solvent
and
com

pressed
air

to
clean
aU

passages
and

discharge
holes
Never

use
wire
or
other

pointed
tool
otherwise

accurately

calibrated
carburetor

will
be

affected

Removal

Remove
the

air
cleaner

2

Disconnect
the
fuel
line
vacuum
line
automatic

choke
harness
and
anti
dieseling
solenoid
harness
from

carburetor

3

Remove
the
throttle
lever

4
Remove
four

nuts
and

washers

retaining
the

carbuTe

tor
to
the

manifold
if

necessary

5
Lift
the
carburetor
and
remove
from
the

manifold

6
Remove
and
discard
the

gasket
used

between
the

carburetor
and
manifold

Disassembly

The
main

jets
and
needle
valves
on
both

primary
and

secondary
sides
are

accessible
from
outside
of
the

carbure

tor
for

disassembly

2
Remove

throttle
return

spring

3
Remove

pump
lever
shaft
take

out

pump
lever

and

pump

connecting
rod

4
Remove

rubber

pipe
from
choke

piston

5

Loosen
off
bolts

securing
servo

diaphragm
in

posi

tion
take
out

diaphragm

6

Back
off
total
of
five
bolts
which
hold
choke
in

position
and
remove
rods
of
starter

system
take
out

choke
chamber

In

removing
chamber
exercise
care
to
avoid

damaging

float

EF
19
ilia

Fig
EF
32

Removing
choke
dwmherand

seroo

diaphragm

7
The

primary
and

secondary
emulsion

tubes
can

be

disassembled

by
removing
the

main
air
bleeds
on
the

individual
sides

In

removing
injector
weight
piston
return

spring
and

ball
care
should
be
excercised
to

prevent
them
from

being

scattered
and
lost

OQ

fI

Fig
EF
33

Removing
emulsion
tubes

8
To

check
the

accelerator

pump
the

pump
cover
is

removed
Be
careful
not

to
lose
the

return

spring
and
inlet

valve
ball

provided
at
the
lower

part
of
the

piston

during

disassemb

ly

Removal
of

bi
metal
cover
is
a

simple
matter
of

removing
three
set
screws

When
it

becomes

necessary
to
take

out
float

pull
shaft

from
float

Note
Under
no

circumstances
should
bi
metal
be
moved

with
excessive
force
since
this

may
cause
a

perma

nent
set
in
bi
metal

making
starting
difficult

ENGINE

Y
Q

0

Fig
EF
34

Disassembling
accelerator

pump
and

hi
metal
cover

1

EC013

Fig
EF
35

Removing
throttle
chamber

9

The
throttle
chamber
can
be
detached
from
the
float

chamber

by
removing
three
set
screws

Do
not
remove
anti

dieseling
solenoid
unless
it
is

necessary
to

change
If

necessary
refer
to
the
item
of

Anti

dieseling
solenoid

page
EF

12

10
It
is

preferable
to
leave

throttle
valve

intact
unless

otherwise

required
If

throttle
valve

must
be
disassembled

to
remedy
a
defect

secondary
throttle
valve

must
be

installed
with

gap
to
be
free

Otherwise

stable

idling
and
slow

speed
performance

will
not
be

obtained
I

o

rJ

01

o

o

Fig
EF
36

Removing
throttle
valve

II
In

disassembling
and

reassembling

interlocking

links
take

care
so
that
each

linkage
has
a
smooth
action

and
that

it
is
not
fitted
in

any
forced

position

Cleaning
and

inspection

Dirt

gum
water
or
carbon
contamination
in
or
on
the

exterior

moving
parts
of
carburetor
are
often

responsible

for

unsatisfactory
performance

For
this
reason
efficient
carburetion

depends
upon

careful

cleaning
and

inspection
while

servicing

1
Blow

aU

passages
and

castings
with

compressed
air

and

blow
off
all

parts
until

dry

Note
Do
not

pass
drills
or
wires

through
calibrated

jets

or

pssages
as

this

may
enlarge
orifice
and

seriously

affect
carburetor
calibration

2
Check
all

parts
for
wear

Replace
worn

part
Especial

ly
the

following
matters
should
be
noted

I
Check
float
needle
and
seat
for
wear

Replace
the

assembly
if
worn

2

Check
the
throttle
and

choke
bores
in

throttle

body

and

cover

casting
for
wear
or

out
of
round

3

Inspect
idle

adjusting
needles
fur
burrs
or

ridges

Replace
as

required

3

Inspect
gaskets
to
ensure
that

they
do
not

appear

hard
or

brittle
and
that
the

edges
are
not
turned
or

distorted
If

any
such
condition
is

detected

they
must
be

replaced

4

Check
fIlter
screen
for

clogging
Clean
and
if
it
is

distorted
or
remains

plugged
replace

EF
20

FUEL
SYSTEM

5
Check
venturi
clusters

for
loose
or
worn

parts
If

damage
or
looseness
exists

replace
cluster

assembly

6
Check
the

linkage
for

operating
condition

7

Inspect
the

operation
of

accelerating
pump

Pour

gasoline
into
the
float
chamber
and

operate
the

throttle
lever

Check
condition
of

gasoline
injection
from

the

accelerating
nozzle

Assembly
and
instalIetion

Assemble

and
install
the
carburetor
in

reverse

sequence

of

disassembly
and
removal

Replace
the

gaskets
if

necessary

When

disassembling
and

reassembling
the
interlock

link

and

related

components
be
careful
not

to
bend
or

deform

SPECIFICATIONS
AND
SERVICE
DATA

Carburetor
model

Applied
engine

Type

Outlet
diameter
mm
in

rom

in
Venturi
diameter

Main

jet

Main
air
bleed

Slow

jet

Slow
air
bleed

Power

jet

Float
level
H
rom

in

Interlock

opening
of

primary
and

secondary
throttle
valve
G
I

Throttle
valve

opening
480
mm
in

Auto
choke

Fast
idle

setting
clearance
A

mm

in

Manual
transmission

Automatic
transmission

Vacuum
break

gap
between

choke
valve
and

carburetor

body
8

mm
in

Manual
transmission

Automatic
transmission

EF
21
the

components

Reassembly
carefully
and

correctly
so
that

all
interlock

links

operate
smoothly

JETS

The
carburetor

performance
depends
on
jets
and
air

bleeds
and
the
vehicle
emissions

largely
depends
on

the

carburetor

performance
That
is

why
these

components

are
manufactured
with
utmost
care

To
clean
them

use

gasoline
and
blow
air
on
them

Changing
jet
or
air

bleed
size

may
cause
ill

vehicle

emission

So

they
should
not
be

changed
their

numbers

DCH3064
for

Manual
transmission

DCH306
5

for
Automatic
transmission

Downdraft

Primary
Secondary

26
1
024
30
1
181

20
0
787
26
1
024

1
95

1
140

1
80

1
80

1
43

1
50

1
215

1
100

1
60

18
to
20
0

709
to
0
748

5
8
0
2283

0

80
to

0
88
0
0315
to
0

0346

1
07
to
1
17
0
0421
to
0

0461

1
140
to
1
260
0
0449

to
0
0496

1

205
to
1

335
0

0474
to
0
0526

ENGINE

Choke

unloader
clearance

carburetor

body
C

between
choke
valve
and

mm
in

Bi
metal
resistance

ohms
2
01

0
07911

8

6t09
0

Accelerator

pump

Injector
hole

Return

spring

Fuel

pressure
mm
in

g
mm

Ib
in

kg
cm
2

psi

kg
lb
0
5

0
0197

78
I
I

0
18
2
6

Manual
transmission

Automatic
transmission
Weight
2
8
6
2

2
9
6
39

Example
1
215

represents
215
100
2
15

mm
0
0846
in

diameter

TROUBLE
DIAGNOSES

AND
CORRECTIONS
There
are
various
causes
of

engine
tarubles
It

some

times

happens
that
the

completely
effective

carburetor

seems

apparently
to
have

some
troubles

when
electric

system
is

defective
Therefore
whenever
the

enigne
has

troubles
electric

system
must
be

checked
first
before

adjusting
the

carburetor
In
the

following
table
the

symptoms
and

causes
of

carburetor
tarubles
and
remedies

for
them

are
listed

to

facilitate

quick

repairs

Troubles

Possible
causes
Remedies

Overflow
Dirt

accumulated
on

needle
valve
Clean
needle
valve

Fuel

pump
pressure
too

high
Repair

pump

Needle
valve
seat

improper
Lap
or

replace

Excessive

fuel

consumption
Fuel
overflows
See
above

Each
main
air

bleed

clogged
Clean

Gauge
plate

adjustment
incorrect

Correct

adjustment

Choke
valve
does

not

open

Adjust

Outlet
valve
seat

of
accelerator

pump
im

proper
Lap
or

replace

Linked

opening
of

secondary
throttle
valve

too

early
Adjust

Power

shortage
Each
main

jet
clogged
Clean

Each
throttle
valve

does
not

fully
open
Adjust

Fuel

pump
operated
improperly
Repair

EF
22

Troubles

Improper
idling

Rough
engine
idle
or

engine

stop

Engine
idle
too
fast

Engine
hesitation
FUEl
SYSTEM

Possible
causes

ruel
strainer

clogged

Vacuum

jet
clogged

Power
valve

operated

improperly

Slow

jet
clogged

Each
throttle
valve
does

not
close

Secondary
throttle

valve

operated
im

properly

Each
throttle
valve
shaft
wear

Packing
between
manifold
and
carburetor

defective

Fuel
overflows

Incorrect
carburetor

adjustment
idle

speed

idle
mixture
choke

setting

Incorrect
basic

ignition
timing

Incorrect
automatic

temperature
control
air

cleaner

Defect
or
malfunction

of

ignition
system

spark

plug
high
tension
cable
breaker

point
ignition
coil
etc

Trouble
in
throttle
link

and
cable

Incorrect
throttle

opener
adjustment

Trouble
in
PCV
valve

Trouble
in
automatic
choke

Defect
or
malfunction
of

ignition
system

spark
plug
high
tension
cable
breaker

point
ignition
coil
etc

Each
main

jet
slow

jet
clogged

By
pass
hole
idle

passage
clogged

Emulsion
tube

clogged

EF
23
Remedies

Clean

Clean

Adjust

Clean

Adjust

Overhaul
and

clean

Replace

Replace
tightening

See
the
first
item

Adjust
idle

speed
mixture
and

timing

Adjust
ignition
timing

Adjust
automatic

temperature
control
air

cleaner

Adjust
or

replace
ignition
system

Check
throttle
link

and
cable

Adjust
throttle

opener

Replace
PCV
valve

Adjust
auotmatic

choke

Adjust
or

replace
ignition
system

Clean

Clean
tube

Clean

Troubles

Car
knock
when

coasting

Engine
does
not

start
ENGINE

Possible

causes

Idling
adjustment
incorrect

Secondary
throttle

valve

operated
im

properly

Incorrect

throttle

opener
adjustment

Trouble
in
PCV
valve

Defect

or
malfunction
of

ignition
system

spark

plug
high
tension
cable

breaker

point
ignition
coil
etc

Fuel
overflows

No
fu
el

Idling
adjustment
incorrect

Fast
idle

adjustment
incorrect

Damaged
anti
dieseling
solenoid

Bi
metal
rod
in

contact
with
hi
metal

case

EF
24
Remedies

Correct

adjustment

Overhaul
and

clean

Adjust
throttle

opener

Replace
PCV
valve

Adjust
or

replace

ignition
system

See
the
first
item

Check

pump
fuel

pipe
and

needle
valve

Correct

adjustment

Correct

adjustment

Replace

Adjust

FUEl
SYSTEM

EVAPORATIVE
EMISSION

CONTROL
SYSTEM

CONTENTS

OESCRI
PTION

Flow

guide
valve

MAINTENANCE

AND

TESTING

Checking
fuel
tank

vapor

liquid
separator

and

vapor
vent
I
ins
EF
25

EF

26

EF

26

EF

26

DESCRIPTION

This

system
consists
of

four
basic
elements

indicated

below

I

Fuel
tank

with

positive
sealing
filler

cap
with
relief

valve

2

Vapor

liquid
separator

3

Vapor
vent
line

4
Flow

guide
valve

The
flow

guide
valve

prevents
blow

by

gas
from

flowing
into
the
fuel
tank

and

guides
fresh
air
into
it

preventing
gasoline

vapor
from

escaping
into
the

carbure

tor
air
cleaner

Fl

me
ester

I

f
Flow

Thev
lve

opens
when

thlp
1l

rO

Inch

Hg

O
Positive
unk

venlI1atlon

PCV
hoe
Checking
fuel

tank
vacuum
relief
valve

operation

Checking
flow

guide
valve
EF
27

EF
27

Flow

guide
valve

operates
and
blow

by

gas
and

gasoline

vapor
flow
as
follows

When
the

engine
is
not

running
the

vapor
vent

line

vapor
liquid
separator
and

fuel
tank

are
filled
with

gasoline
vapor
produced
in
the

sealed

type
fuel
tank

A

flow

guide
valve

opens
when
the

gas

pressure
is

above

IOromHg
0
4

in

Hg
The

gas

passed
through
the
flow

guide
valve
2
is

accumulated
in

the
crankcase

Once
the

engine
starts

evaporates
in

the
crankcase

manifold
and

carburetor
air
cleaner

is
sucked
into
the
manifold
for

combustion
When
the

pressure
of
the

sealed

type
fuel

tank

vapor
liquid

separator
and

vapor
vent
line

becomes

negative
by

decreasing
the
fuel
the

flow

guide
valve
I

opens
to
send
fresh
air
from
the
carburetor
air
cleaner

to

the

fuel
tank

lill
K
riquidllepilrflOr

T

VilPOl
vent

line
Positiveteilling

lillercap

Fig
EF
37

Evaporative
emission

control

system

EF
25