1969 DATSUN 510 fuel tank capacity

Fuel

System

DESCRIPTION

FUEL
TANK

FUEL
PUMP

CARBURETTOR
IDLING
ADJUSTMENT

FAST
IDLE
OPENING
ADJUSTMENT

THROTTLE
VALVES
INTERLOCK
OPENING

DASHPOT

DESCRIPTION

The

diaphragm
type
fuel

pump
shown
in

Fig
D
1
feeds

fuel

from
the
tank
to
the
carburettor
in
a

regulated
supply

according
to
the
needs
of
the

engine
A
cartridge
type
fuel

strainer

prevents
any
dirt
from

reaching
the

pump
inlet
valve

The

carburettor
fitted
to

the

engine
is
either
a
down

draught
two
barrel

type
equipped
with
a
throttle

operated

acceleration

pump
and
power
valve
mechanism

See
Fig
D
2

or
a
twin
SU
carburettor
of
the

type
shown
in

Fig
D
3
In
the

two
barrel

type
carburettor

fuel
flows
from
the

passage
at
the

bottom
of
the
float
chamber

passes
through
the

primary
main

jet
and
mixes
with
air

introduced

through
the
main
air
bleed

screw

The

petrol
and
air
mixture
is

injected
into
the
venturi

through
the
main
nozzle

Each
time
the
accelerator

pedal
is

depressed
the
throttle

opens
and
the
accelerator

pump
forces
a

jet
of

petrol
into
the

air
stream
to
allow
the

engine
to
accelerate

smoothly
See

Fig

0
4
The

power
valve
mechanism
is

operated
automatically

according
to
the
demands
made

by
the

engine
Under
light
load

i
e

part
throttle
conditions
the
intake
manifold

depression
is

transmitted
below
the
throttle
valve
the
vacuum

pulls
a

piston

upwards
against
a

spring
and
leaves
the

power
valve
closed

allowing
additional
air
to
be

admitted
through
the
air
bleed
screw

and
thereby
weaken
the

petrol
and
air
mixture
When
the
vacuum

below
the
throttle
vaJve
is
lowered

during
full
load
conditions

the

piston
is

pushed
down
opening
the

power
valve
and
providing

additional
fuel
to
enrichen
the
mixture

The
model

HJ
L
38W6
SU
twin
carburettor
is
of

the

horizontal
variable
venturi

type
and
is
used

only
on
the
1600

and
1800
cc

engines
In
this

type
of
carburettor
a

constant

flow
of
intake
air
is

maintained

by
the

automatically
adjusted

venturi

opening
this
is
accomplished

by
the
suction

piston

sliding
in
accordance
with

changes
in
the
volume
of
intake
air

Referring
to

Fig
D
5
the
suction
chamber
is
mounted
above

the
venturi
The
suction

piston
slides
vertically
within
the

chamber

and

changes
the
venturi

opening
area
The

piston
is

operated
by
a

difference
between
the

upper
vacuum

pressure

which
is

applied
through
the
suction

poct
and
the
atmospheric

pressure
which

is
introduced

through
the
air
hole
from
the
air

cleaner

The
amount

by
which
the
throttle
is

opened
causes
the

suction

piston
to
rise
or
fall
under
the
intluence
of
the

engine

suction
The

pozzle

opening
therefore

changes
and

provides
an

optimum
air
fuel
mixture
at
all

engine
speeds

The

cartridge
type
fuel
strainer
utilizes
a
fibre
strainer

element
which
should
be

replaced
every
20
000
km
12
000

miles
Removal
of
the
fuel
strainer
is
a

simple
operation
but
as

it
cannot
be
drained
the
strainer
should
not
be
removed
when
CARBURETIOR
Removal
and
Overhaul

FLOAT
LEVEL
Adjustment

SU
TWIN
CARBURmORS

Adjustments

SU
TWIN
CARBURmORS

Dismantling

SU
TWIN
CARBURETTORS

Inspection

STARTING
INTERLOCK
VALVE
OPENING

HYDRAULIC
DAMPER

the
tank
is

full
unless

absolutely
necessary

A

viscous

paper
type
air
cleaner
element
is
fitted
which

does
not

require
cleaning
and
should
be

repl
ced

every
40
000
km

24
000
miles
The
air

cleaner
fitted
on
the

single
carburettor

is
equipped
with
an

idling
compensator
to

prevent
the
mixture

from

becoming
too

rich
at

high
idling

temperatures
Additional

fresh
air
is
introduced
into
the
inlet
manifold

by
the
action
of

a
bimettalic

strip
located
in
the
air
cleaner
When
the

temperature

under
the
bonnet
is

high
the
bimetal
is

heated

by
the
hot
inlet

air
and
lifts
to
allow
the
valve
to

open
The

idling
compensator

valve

partially
opens
at

550
I310F
and
is

fully
open
at

650C

l490F
The
unit
cannot
be
dismantled
as

it
is

pre
sealed
and

correctly
adjusted
for
valve

timing
Fig
D
6
shows
the

layout

of

the
idling
compensator
piping

FUEL
TANK

Replacing

The
fuel
tank
can
be
removed
in
the
following
manner

Remove
the
rear
seat

and
back
rest

2
Take
out
the
board
behind
the
back
rest

3
Take
out
the

luggage
compartment
lining
board
and

disconnect
the
cable
to
the

petrol
gauge
unit

4
Disconnect
the
petrol
filler
tube
from
the
tank

5
Remove
the
tank
retaining
bolts
and
disconnect
the

rubber
fuel
outlet
and
return
hoses

Installation
is

a
reversal
of
the
removal

procedure
always

ensure
that
the
fuel
lines
arc
carefully
checked
for

signs
of

damage
before

replacing
the
tank

FUEL
PUMP

Testing

Pressure
and
capacity
tests
can
be
carried
out
with
the

pump
installed
in
the

following
manner

Static

pressure
test

Disconnect
the
fuel
line
at

the
carburettor
install
an

adaptor
tee

fitting
and
suitable

pressure
gauge
to
the
fuel
line

between
carburettor
and
fuel

pump
Start
the
engine
and
run
it

at

varying
speeds

The

reading
on

the
gauge
should
be
0
18
0
24

kg
sq

cm
2
6
34
Ib

sq
in
If
the

pressure
is
below
the

specified

figure
then
either
one

part
of
the

pump
has
worn

excessively

or

general
wear
has
occured
to

all
the

working
parts
The
faults

may
include
a

ruptured
diaphragm
worn
and

warped
valves

33

and
seats
or
a
weak

diaphragm
return

spring

A

pressure
above
the

specified
figure
may
be
due
to

an

excessively
strong
and
tight
diaphragm

Capacity
test

The

capacity
test
can
be

carried
out
when
the
static

pressure
has
been
tested
and
conforms
with
the

specified
figure

of
0
18

kg
sq
cm
2
6Ib

sq
inJ

Disconnect
the
fuel
line
at

the
carburettor

and

place
a

container
under
the
end
of
the

pipe
to
act
as
a
fuel

sump

Start
the

engine
and
run
it
at
a

speed
of
1000

Lp
m
The

amount

of
fuel
delivered
from
the

pump
in
one
minutc
should

be

1000
cc
2
1
US

pt

If

petrol
does
not
flow
from
the

opcned
end
of

the
pipe

at
the
correct
rate
then
either
the
fuel

pipe
is

clogged
or

the

pump
is
not

operating
correctly

If
the
latter
cause
is

suspected
the

pump
must
be
removed

and

inspected
as
described
below

FUEL
PUMP

Removing
and

Dismantling

Before

removing
the
pump
take
off
the

petrol
tank

cap

and
disconnect
the

pump
inlet
and
outlet

pipes
Blow

through

the

pipes
with

compressed
air
to

make
sure

that

they
are
not

clogged

Remove
the

pump
retaining
nuts

withdraw
the

pump
and

dismantle
it
in
the

following
order

Referring
to

Fig
D
l

Take
out
the
screws

holding
the
two

body
halves

together

and

scparate
the

upper
body
from

the
lower

body

2
Remove
the

cap
and

cap
gasket

3
Unscrew
the
eI
bow
and
connector

4
Take
off

the
valve
retainer
and
remove
the
two
valves

5
To
remove
the

diaphragm
diaphragm
spring
and
lower

body
sealing
washer

press
the

diaphragm
down

against

the
force
of
the

spring
and
tilt
the

diaphragm
at
the
same

time
so
that
the

pull
rod
can
be
unhooked
from
the
rocker

arm

link

Fig
D
7

The
rocker
arm

pin
can

be
driven
out
with
a
suitable

drift

FUEL
PUMP

Inspection
and

Assembly

Check
the

uppcr
and

lower

body
halves
for
cracks

Inspect

the
valve
and
valve

spring
assembly
for

signs
of
wear
and
make

sure
that
the

diaphragm
is
not

holed
or

cracked
also
make
sure

that
the
rocker
arm
is
not
worn
at
the

point
of
contact
with

the

camshaft

The
rocker
arm

pin
may
cause

oil

leakage
if
worn

and

should
be
renewed
Assembly
is
a
reversal
of
the
dismantling
procedure

noting
the

following
points

Fit
new

gaskets
and
lubricate
the
rocker
arm
link
and
the

rocker
arm

pin
before

installing

The

pump
can
be
tested

by
holding
it
approximately
I

metre
3

feet
above

the
level
of
fuel

and
with
a

pipe
connected

between
the
pump
and
fuel
strainer

Operate
the
rocker
ann

by
hand
the

pump
is

operating

correctly
if
fuel
is
drawn

up
soon
after

the
rocker
ann
is

released

CARBURETTOR
IDLING
ADJUSTMENT

The

idling
speed
cannot
be

adjusted
satisfactorily
if
the

ignition
timing
is
incorrect

if
the
spark
plugs
are

dirty
or
if

the
valve
clearances
are
not

correctly
adjusted

Before

adjusting
the

idling
speed
set
the
hot
valve

clearances

t
o
0
25
mm
0
0098
in
for
the
intake
valves

and

0
30
mm
0
0118
in
for
the
exhaust
valves
as
described
in

the
ENGINE

section

Idling
adjustment
is
carried
out

with
the
throttle

stop

screw
in

conjunction
with
the

idling
adjustment
screw

See

Fig
D
8

Run
the

engine
until
it
attains
its
normal

operating

temperature
and
then
switch
off

Starting
from
the
fully
closed

position
unscrew
the

idling
adjustment
screw

by
approximately
three
turns

Screw
the
throttle

stop
screw
in

by
two
or
tftr
e
turns
and

start

th
engine

Unscrew
the
throttle

stop
screw
until
the

engine
commences

to
run

unevenly
then
screw
in
the

idling
adjustment
screw
so

that
the
engine
runs

smoothly
at
the

highest
speed

Readjust
the
throttle

stop
screw
to

drop
the

engine
speed

of

approximately
600
r

p
m
is
obtained

WARNING
Do
not

attempt
to
screw

the

idling
adjustment

screw

down
completely
or
the

tip
of
the
screw

may
be

damaged

FAST
IDLE
OPENING
ADJUSTMENT

The
choke
valve
is

synchronized
with
the
throttle
valve

and
connected
to
it

by
levers
as
shown
in

Fig
D
9
The
fast

idle
opening
can
be
check

by
fully
closing
the
choke
valve
and

measuring
the
clearance
between
the

primary
throttle
valve
and

the
wall
of

the
throttle
chamber
This
clearance

being
shown

as
A

in
the
illustration
The
clearance
for

the
carburettor

types
is
as
follows

Carburettor

type
Throttle

opening

angle

180

180

190
Dimension
A

213304
361

13304
4
I

13282
331
1
55mm
0
06lin

1
55mm
0
06Iin

1
3
mm
0
051
in

35

The

type
D3034C
carburettor
has
certain
additional

features

These
include
a

power
valve
mechanism
to

improve
the

performance

at

high
speed
a
fuel
cut
off
valve
which
cuts
the
fuel

supply

when
the

ignition
key
is
turned
to
the
off
position
and
an

idling

limiter
to

maintain
the

emissions
below
a

certain
level

Sectional
views
of
the
two

types
of

pumps
are
shown
in

Figs
8
1
and
B
2
An
EP
3
electrical
fuel

pump
is

located
in
the

centre

of
the
spare
wheel

housing
in
the
boot

Fig
B
3
shows
a

sectional
view
of
the

pump
with
its
contact

the
pump
mechanisms

solenoid

relay
and
built
in
filter

The
air
cleaner
uses
a

viscous

paper
type
element
which

should
be

replaced
every
40
000
km
24
000
miles

Cleaning

is
not

required
and
should
not
be

attempted

The

cartridge
type
fuel
strainer

incorporates
a
fibre
clement

which
should
be
renewed
at
inervals
not

exceeding
40
000
km

24
000
miles
Fit
B
4
shows
a
sectional
view
of

the
assembly

The
fuel
lines
should
not
be
disconnected
from
the
strainer
when

the
fuel
tank
is
full

unless
absolutely
necessary
as
the
strainer

is
below
the
fuel
level

FUEL
PUMP

Testing

Disconnect
the
fuel
hose
from
the

pump
outlet
Connect

a
hose
with

an
inner
diameter
of
approximately
6
mm
0
024

in
to

the

pump
outlet
and

place
a

container
under
the
end
of

the

pipe
Note
that
the
inner

diameter
of
the

pipe
must
not
be

too

small
or

the
pipe
will
be

incapable
of

delivering
the
correct

quantity
of
fuel
when

testing
Hold
the
end
of
the
hose
above
the

level
of
the

pump
and

operate
the

pump
for
more
than
IS

seconds
to
check
the

delivery
capacity
The

capacity
should
be

I
400
cc

3
24
U
S

pts
in
one
minute
or
less
The

pump
must

be
removed
from
the
vehicle
if
it
does
not

operate
or
if
a

reduced

quantity
of
fuel
flows
from
the
end
of
the
hose
Remove

the
pump
from
the
vehicle
and
test
as
follows

Connect
the

pump
to
a

fully
charged
battery
If
the

pump

now

operates
and

discharges
fuel

correctly
the
fault
does
not

lie
in
the

pump
but

may
be
attributed
to

any
of
the

following

causes

Battery
voltage
drop

poor
battery
earth
loose

wiring

loose
connections
blocked
hoses
or
a

faulty
carburettor

If
the

pump
does
not

operate
and

discharge
fuel
when

connected
to
the

battery
then
the

pump
itself
is

faulty
and

must
be
checked
as
follows

First
make
sure
that
current
is

flowing
This
will
be
indica

ted

by
sparking
at

the
tenninals
If
current
flows
the
trouble
is

caused

by
a

sticking

pump
plunger
or

piston
The

pump
must

be
dismantled
in

this
case
and
the

parts
thoroughly
cleaned
in

petrol

If

the
current
does
not
flow
a
coil
or
lead
wire
is
broken

and
the

pump
must

be
renewed
A

reduced
fuel
flow
is
caused

by
a

faulty
pump
inlet
or

discharged
valve
or
blocked
filter

mesh
The

pump
must

of
course

be
dismantled
and
serviced
as

necessary

FUEL
PUMP

Removing
and

Dismantling

Remove
the
bolts

attaching
the
fuel

pump
cover
to

the

floor

panel
see

Fig
B
S
Remove
the
bolts

attaching
the

pump
to
the
cover

2
Disconnect
the
cable
and
fuel
hoses
Withdraw

the

pump
Dismantle
as
follows

Slacken
the

locking
band
screws
and

remove
the
strainer

strainer

spring
filter
strainer
seal
and

locking
band

Remove
the

snap
ring
Withdraw
the
four
screws
from
the

yoke
and
remove

the
electromagnetic
ulJ
it
Press
the

plunger
down
and
withdraw
the
inlet
vaive

the

packing

and
the
cylinder
and

plunger
assembly

A
defective
eledrical
unit

cannot
be
dismantled
as

it
is

sealed
and
must

be
renewed
as
a

complete
unit

FUEL
PUMP

Inspection
and

Assembly

Wash
the
strainer
filter
and

gasket
in

petrol
and

dry
using

compressed
air
Renew
the
filter
and

gasket
if

necessary
Note

that
the
filter
should
be
cleaned
every
40
000

km
24
000

miles
Wash
the

plunger
piston
and
inlet
valve
in

petrol
and

make
sure
the

piston
moves

smoothly
in
the

cylinder
Replace

the

parts
if
found
to
be
defective

Insert
the

plunger
assembly
into
the

cylinder
of
the
electri

cal
unit
and
move

the

assembly
up
and
down
to

make
sure
tha
t

the
contacts
are

operated
If
the
contacts
do
not

operate
the

electrical
unit
is

faulty
and
must

be
renewed

Assembly
is
a
reversal
of

the
dismantling
procedures
tak

ing
care
to
renew
the

gaskets
as

necessary

CARBURETIOR

Idling
Adjustment

The
D3034C
carburettor
fitted
to

engines
equipped
with

an
emission
control

system
must
be

adjusted
as
described
under

the

heading
IGNITION
TIMING
AND
IDLING
SPEED
in
the

section
EMISSION
CONTROL
SYSTEM

Reference
should
be
made
to
carburettor

idling
adjustment

procedures
for
the
L14
L16

and
LI8

engines
when

adjusting

the
type
DAK
340
carburettor
fitted
to
the
G
18

engine
A
smooth

engine
speed
of

approximately
550

rpm
should
be
attained
in

this
case

FUEL
lEVEL

Adjustment
DAK
340earburettor

A
constant
fuellevcl
in
the
float
chamber
is
maintained

by

the
float
and
needle
valve
See

Fig
8
6
If

the
fuel
level
does
not

correspond
with
the
level

gauge
line
it
will
be

necessary
to

care

fully
bend
the
float
seat
until
the
float

upper
position
is

correctly

set

The
clearance
H
between
valve
stem
and
float
seat

should

be
I
5
mm
0
0059
in
with
the
float

fully
lifted

Adjustment

can
be
carried
out

by
carefully
bending
the
float
stopper
3

FUEL
lEVEL

Adjustment
D3034Ccarburettnr

The
fuel
level
should

correspond
with
the
level

gauge
line

Adjustment
can

be
carried
out
if

necessary
by
changing
the

gaskets
between
the
float
chamber

body
and
needle
valve
seat

The
gaskets
are
shown
as
item
4
in

Fig
B
7
When

correctly

adjusted
there
should
be
a

clearance
of

approximately
7
mm

0
027
in
between
float
and
chamber
as
indicated

STARTING

INTERLOCK
VALVE
OPENING

The

choke
valve
at
its

fully
closed
position
automatically

opens
the
throttle
valve
to
an

optimum
angle
of
14

degrees
on

the

type
DAK
340
carburettor
and
13
5

degrees
on
the
D3034C

carburettor
With
the
choke
valve

fully
closed
the
clearance

G

I
in

Fig
8
should
be
1

I
mm
0
0433

in
This
clearance

S19