fuel cap DATSUN PICK-UP 1977 User Guide

DESCRIPTION

FUEL

PUMP
TESTING

STATIC
PRESSURE
TEST

CAPACITY
TEST

DESCRIPTION

The
fuel

pump
transfers
fuel
from

the
tank
to
the
carburetor
in
sufficient

quantity
to
meet
the

engine
require

ments
at

any
speed
or

load

The
fuel

pump
is
a

pulsating
type

designed
for

easy
maintenance
It

con

sists
of
a

body
a

rocker
arm

assembly

a

fuel

diaphragm
a
fuel

diaphragm

spring
seal
inlet
and
outlet

valves

Figure
EF
19

shows
a
cross
sectional

view
of
the

pump

The
fuel

diaphragm
consists

of

specially
treated
rubber
which
is

not

affected

by

gasoline
and
held
in

place

by
two

metal
discs
and

a

pull
rod

FUEL

PUMP

TESTING

A
fuel

pump
is

operating

properly

when
its

pressure
is

within

specifica

tions

and
its

capacity
is

equal
to
the

engine
s

requirements
at
all

speeds

Pressure
and

capacity
must
be
deter

mined

by
two
tests
while
the

pump
is

still

mounted
on
the

engine
Be
sure

there
is
fuel
in

the
tank
when

carrying

out
the
tests
Engine
Fuel

MECHANICAL
FUEL
PUMP

CONTENTS

EF
9

EF
9

EF
9

EF
10
REMOVAL
AND
DISASSEMBLY

INSPECTION

ASSEMBL
Y
EF

10

EF
10

EF

11

1

1

Outlet
valve

2

Diaphragm

3

Diaphragm
spring

4
Inlet
valve

S
Rocker
ann
EF006

Fig
EF
19
Schematic
view

of
fuel
pump

STATIC
PRESSURE
TEST

The
static

pressure
test
should
be

made
as
follows

I
Disconnect
fuel
line
between
car

buretor
and
fuel

pump

2
Connect
a
rubber
hose
to
each

open
end
of
a
T
connector
and
con

nect
this
connector
hose

assembly
be

tween
carburetor
and
fuel

pump
Note
Locate
this
T
connector
as

close
to

carburetor
as

possible

3
Connect
a

suitable

pressure
gauge

to

the

opening
of
T
connector
and

fasten
hose
between
carburetor
and

T
connector
with

a

clip
securely

EF
9

4

Run
the

engine
at

varying
speeds

5

The

pressure
gauge
indicates

static
fuel

pressure
in
the
line

The

gauge
reading
should
be

within
the

following
range

0
21
to
0

27

kg
em2

3
0

to
3

8

psi

Note
If

the
fuel
in
carburetor
float

chamber
has
run
out

and

engine
has

stopped
clip
and

pour
fuel

into

carburetor
Fasten

clip
secure

ly
and

repe
1
static

pressure
test

Pressure
below
the
lower
limit
indi

cates
extreme
wear
on
one

part
or

a

small
amount
of
wear
on
each

working

part
It

also
indicates

ruptured
dia

phragm
worn

warped
dirty
or

gum

ming
valves
and
seats
or
a
weak

diaphragm
return

spring
Pressure

above
the

upper
limit
indicates
an

excessively
strong
tension
of
dia

phragm
return

spring
or
a

diaphragm

that
is
too

tight
Both
of
these
condi

tions

require
the
removal
of

pump

assembly
for

replacement
or

repair

CAPACITY
TEST

The

capacity
test
is

made

only

when
static

pressure
is
within
the

specifications
To

make
this
test

pro

ceed

as
follows

1

Disconnect

pressure
gauge
from

T
connector
and
in
its
vacant

place

install
a

suitable
container

as
a
fuel

sump

2
Run

engine
at
1

000

rpm

3
The

pump
should

deliver
1
000

cc

2
11

US

pt
of
fuel
in

one
minute
or

less

If
little

or
no
fuel
flows
from
the

open
end
of

pipe
it
is
an

indication

that
fuel
line
is

clogged
or

pump
is

malfunctioning

REMOVAL
AND

DISASSEMBLY

Remove
fuel

pump
assembly
by

unscrewing
two

mounting
nuts
and

disassemble
in

the

following
order

1

Separate

upper
body
and
lower

body
by

unscrewing
body
set
screws
Engine
Fuel

2

Take
off

cap
and

cap
gasket
by

removing
cap
screws

3
Unscrew
elbow

and
connector

4
Take
off
valve

retainer

by
un

screwing
two
retainer

screws
and
re

move
two
valves

5
To
remove

diaphragm

press

down
its

center

against
spring
force

With

diaphragm
pressed
down

tilt
it

until
the
end
of

pull
rod
touches
the

inne

wall
of

body
Then
release

diaphragm
to
unhook

push
rod
Be

careful

during
this

operation
not
to

damage
diaphragm
or
oil
se
L

i
J

EFOO7

Fig
EF

20
Remouing
pull
rod

6
Drive
rocker
arm

pin
out
with
a

press
or
hammer

8

o

6

7

8

@

INSPECTION

I

Check

upper
body
and
lower

body
for
cracks

EF
10
I
fuel

pump
cap

2

Cap
gasket

3
Valve

packing

4

fuel

pump
val
e

assembly

S
Valve
retainer

6

Diaphragm
assembly

7

Diaphragm
spring

8
PuRro

9

Lower
body
seal

washer

10
Lower
body
seal

11
Inkl
connector

12
Outlet
connector

13
Rocker
arm

spring

14
Rocker
arm

I
S
Rocker

artyl
side

pin

16
Fuel
pump
packing

17

Spacer
fuel

pump

fo
cylinder
block

EF510

Fig
EF
21
Slruc
ure
of
fuel

pump

2
Check

valve
assembly
for
wear
on

valve
and
valve

spring
Blow
valve

assembly
with
brea
th
to
examine
its

function

3
Check

diaphragm
for

small
holes

carcks
or
wear

4

Check

rocker
arm
for
wear
at
the

mating
portion
with

camshaft

5

Check
rocker
arm

pin
for
wear
A

worn

pin
may
cause
oil

leakage

6
Check
all

other

components
for

any
abnormalities
and

replace
if
neces

sary

DESCRIPTION

INSPECTION

REMOVAL
AND

INSTALLATION

DESCRIPTION

The
electric
fuel

pump
is

adopted

on
air

conditioner

equipped
models
Engine
Fuel

ASSEMBLY

Reverse

the
order
of

disassembly

Closely
observe
the

following
instruc

tions

L

Use
new

gaskets

2

Lubricate
rocker
ann
rocker
arm

link
and

rocker
arm

pin
before
installa

tion
3

To
test
the

function

proceed
as

follows

Position
fuel

pump
assembly
about

I

meter
3
3
ft

above
fuel
level
of

fuel

strainer
and
connect
a

pipe
from

strainer
to
fuel

pump

Operate
rocker

arm
by
hand
If

fuel

is

drawn

up
soon
after
rocker
arm
is

released

fuel

pump
is

functioning

properly

ELECTRIC
FUEL
PUMP

CONTENTS

EF
11

EF
11

EF
12
DISASSEMBL
Y

ASSEMBL
Y

TROUBLE

DIAGNOSES
AND

CORRECTIONS
EF
12

EF
12

The
silicon
transistor

type
fuel

pump

consists
of

a
transistor
diodes
a

sole

I
Tr

lOsistor

6
Ou
tIet
valve

2

Plunger

7
Return

spring

3

Diaphragm

8
Filter

4

Diode

9

Magnet

5

Magnet
coil

10
Inlet
valve

INSPECTION

I
Disconnect
fuel
hose
at

pump

outlet

2

Connect

a
suitable
hose

approxi

mately
6

mm
0

24
in
inner

dia

meter
to

pump
outlet
ev
J

J

Note
If
diameter
is
too
small
the

following

proper
delivery

capacity

cannot
be
obtained
even
if

pump

functions

properly

EF
11
EF
13

noid
a

pump
mechanism
and
filter

parts

I
T
nsistor

2

Re
ist
f
I

3
Dinde

4

Signal
coil

5
Main
coil

6
Resistor
3

7
Zener
dlOdl

8

Resistor
2

EF719

Fig
EF
22
Construction

of
electric

fuel

pump

3

With
hose
outlet
in
a

higher
posi

tion

than

pump

operate
pump
and

check

delivery
capacity
for
more
than

15

seconds

4

The

capacity
should
be
I
400

cc

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

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

Throttle
chamber

parts

I
Idle

limiter

cap

2
Idle

adjust
screw

3
Idle

adjust
screw

sprinl

4
Throttle

adjust
screw

5
Throttle

adjust
screw

sprini

6
Primary
and
secondary

throttle
valves

7

Nut

Notc

Do
not
remove
the

parlS

marked
with
an
asterisk

@ff

EF827

Fig
EF
66

Removing
throttle
chamlHr

parta

Assembly

To

assemble
reverse
the
disassem

bly

procedcre
taking
care
to
the

following

I

Thoroughly
wash

all
the

parts

before

assembling

2

Inspect
gaskets
to
see
if

they
appear
hard
or
brittle
or
if

edges
are

torn
or

distorted

If

any
of
such
undesirable
condi

tions
is

noted

they
must
be

replaced

3
Install

jet
and
air
bleed

having
the

same
size
number

as
that
of

original
one

4
After
reassembling
carburetor

check
each

rotating
portion
or
sliding

portion
for
smooth

operation

EF

33

Emission
Control

System

EARLY

FUEL

EVAPORATIVE

SYSTEM
E

F
E

DESCRIPTION
spring
and

counterweight
which
are

assembled
on
the

valve
shaft

projecting

to
the

rear
outside
of
the
exhaust

manifold
The

counterweight
is
se

cured
to
the
valve
shaft
with

key
bolt

and

snap
ring
EC
4
A

control
valve
welded
to

the

valve
shaft
is

wtalled
on
the

exhaust

manifold

through

bushing
This
con

trol

valve
is

called
Heat

control

valve
The
heat
control

valve
is

ac

luated

by
the

coil

spring
thermostat
Construction
of
the

early
fuel

evap

orative

system
is

shown
in

Figure

r
I

1

@

rW

9

Sc
w

10
Thennostat

spring

11

Coil
spriiig

12
Control
valve
shaft

13
Heat
control

valve

14

Bushing

15

Cap

16
Exhaust
manifold
1
Intake
manifold

2
Stove

gasket

ManifoktstOve

4
Heat
shield

plate

5

Snap
ring

6

Counterweight

7

Key

g

Stoppel
pin

EC532

Fig
EC
4
Early
Fuel

Evaporutive
tem
E
F
E

The

early
fuel

evaporative
system
is

provided
with
a
chamber
above

a

manifold
stove
moonted
between
the

intake
and
exhaust

manifolds

During

engine

warming
up
air
fuel
mixture
in

the

carburetor
is

heated
in
the
cham

bet

by
exhaust

gases
This
results
in

improved
evaporation
of

atomized
fuel

droplets
in
the
mixture
and
in

smaller

content
of

hydrocarbons
He
in
the

exhaust

gas
especially
in

cold
weather

operation

The
exhaust

gas
flow
from
the

engine
is

obstructed

by
the
heat
con

trol

valve
in
the

exhaust
manifold
and
is

changed
in

direction
as
shown

by

the
solid

lines
in

Figure
EC
4
The

exhaust

gas
heats
the
manifold
stove

Open
close

operation
of
the

heat

control
valve
is
controlled

by
the

counterweight
and
thermostat

spring

which
is
sensitive
to
the

ambient
tem

perature
around
the

exhaust
manifold
With
this
condition
the

heat
control

valve
is
in

the

fully
closed

position

obstructing
the
flow
of

exhaust

gas
As

engine
tempera
lure

goes
up
and

the

ambient

temperature
becomes

high

enough
to
actuate
the
thermostat

spring
the

counterweight
begins
to

rotate
clockwise
and

again
comes
into

con

tact
with

the

stopper
pin
With
this

condition
the

heat
control
valve
is
in

the
full

open
position
and
exhaust

gas

passes
through
the
exhaust
manifold
as

shown

by
the
dotted

lines
in

Figure

EC
4
without
heati

ng
the
manifold

stove
OPERATION

The

counterweight
rotates
counter

clockwise
and

stops
at

the

stopper
pin

mounted
on
the
exhaust

manifold

while

the

engine
temperature
is
low

EC
6

3

Check

ignition
system
with

regard

to

the

following
items

Refer
to

Inspection
of

Ignition
System

1

Ignition
AMP

2
Distributor
Emission
Control

System

3

Ignition
coil

4

High
tension
code

5

Spark

plug

4

Check
idle

CO

adjustment
Refer

to

Inspection
of
Idle

CO

Adjustment
Note
Even
if
there
is

nothing

wrong

with

engine
the

warning
lamp
may

come
on
if
vebicle
is

being
driven

on
a

steep
slope

continuously
in

lower

gears
at

high
engine
speeds

EVAPORATIVE

EMISSION

CONTROL
SYSTEM

CONTENTS

DESCRIPTION

OPERATION

INSPECTION

FUEL
TANK

VAPOR
LIQUID

SEPARATOR

AND

VAPOR
VENT
LINE

DESCRIPTION

The

evaporative
emission
control

system
is

used
to

reduce

hydrocarbons

emitted
to
the

atmosphere
from
the

fuel

system
This

reduction
of

hydro
EC
30

EC

30

EC

31
CARBON

CANISTER
PURGE
CONTROL

VALVE

CARBON
CANISTER

FILTER

FUEL

TANK

VACUUM
RELIEF
VALVE
IEC
32

IEC
32

EC

32

EC
31

carbons
is

accomplished
by
activated

charcoals
in
the
carbon
canister

This

system
is
made

up
to

the

following

I

Fuel
tank
with

positive

sealing
filler

cap

@
2

Vapor
liquid
separator

3

Vapor
vent

line

4
Carbon

canister

5
Vacuum

signal
line

6
Canister

purge
line

5

OPERATION

Fuel

vapors
from

the
sealed
fuel

tank
are
led

into
the
carbon
canister
1
Fuel
tank

2
Fuel
nIler

cap
with
vacuum

relief

valve

3

liquid

vapor
separator
4

Vapor
vent
line

5

Canister

purge
line

6
Vacuum

signal
line

7
Carbon

canister

EF274

Fig
EC
76

Schematic

drawing
of
l
Iaporotive

emiaion

control6ydem

The

canister
is
fined
with
activated

charcoals

to
absorb

the
fuel

vapors

EC
30
when
the

engirie
is

at
rest
or
at

idlin
ll

See

Figure
EC

77

J

1
Fuel
tank

2

Fuel
f1l1er

cap
with

vacuum

relief
valve

3

Liquid
vapor

separator

4

Vapor
vent
line

5
Vacuum

signalUne

As
the
throttle
valve

opens
and

vehicle

speed
increases

vacuum

pres

sure
in

the
vacuum

signal
line
forces

rHL
JL

I

EC785

INSPECTION

FUEL
TANK

VAPOR

LIQUID
SEPARATOR

AND

VAPOR
VENT
LINE

I

Check
all
hoses
and
fuel

tank

mler

cap

2
Disconnect
the

vapor
vent

line

connecting
carbon
canister
to

vapor

liquid
separator

3
Connect
a
3

way
connector

a
Emission

Control

System

Close
at

idling

Open
at
rest

i

J

17
f

Fuel

vapor

6
Canister
purge
line

7
Throttle
valv

8

Engine

9
Carbon
canister

10
Activated
carbon

11

Screen
12
Filter

13

Purge
control
valve

14

Spring

15

Diaphragm

16
Fixed

orifice
i

j

EC784

Fig
EC
77

Evaporative
emu
ion
control

sy
tem

Fuel

vapor
flow
when

engine
i6

at
red
or

idling

the

purge
control
valve
to

open
and

admits
an

orifice
to
intake
manifold

and
fuel

vapor
is

then
drawn
into
the

I

J

o
I

Fuel

vapor

Fresh
air
intake

manifold

through
the
canister

purge
line
See

Figure
EC
7B

Fig
EC
78

Evaporative
emiuion
control

system

Fuel

vapor
flow
when

engine
i

running

manometer
and
a
cock
or
an

equiva

lent
3

way

charge
cock
to

the
end
of

the

vent
line

4

Supply
fresh
air
into

the

vapor

vent
line

through
the
cock
little

by

little
until

pressure
becomes
368

mrnH20

14
5
inH20

5
Shut
the
cock

completely
and

leave
it

unattended

6
After
2
5
minutes

measure
the

height
of
the

liquid
in
the

manometer

7

Variation
of

height
should
remain

EC
31
with
25
mmH20
0
98
inH20

8
When
filler

cap
does
not
close

completely
the

height
should

drop
to

zero
in

a
short
time

9
I
f

the

height
does
not

drop
to

zero
in

a
short
time
when
filler

cap
is

removed
it
is

the
cause
of
a

stuffy

hose

Note
In

case
the

vent
line
is

stuffy

the

breathing
in
fuel
tank
is
not

thoroughly
made
thus

causing
in