engine DATSUN PICK-UP 1977 Service Manual

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

Condition

Engine
hesitation

Engine
does
not

start
Engine
Fuel

Probable

cause

Main

jet
or
slow

jet
clogged

By
pass
hole
idle

passage
dogged

Emulsion
tube

dogged

Idling
adjustment
incorrect

Secondary
throttle
valve

operating

im

properly

Altitude

compensator
setting
incorrect

Cali

fornia
models

Fuel
overflows

No
fuel

Idling

adjustment
incorrect

Fast
idle

adjustment
incorrect

Damaged
anti
dieseling
solenoid

EF
37
Corrective
action

Clean

Clean
tube

Clean

Adjust

Overhaul
and
clean

Correct
H
L
lever

position

See
condition
overflow

Check

pump
fuel

pipe
and
needle
valve

Adjust

Adjust

Replace

There
are
three

types
of
control

system
These
are

J

Closed

type
CIllnkcase
emission

control

system
Emission
Control

System

of

GENERAL

DESCRIPTION

2

Exhaust
emission

control

system

3

Evaporative
ell
lhsion

control

sys

tem

Pericxiic

inspection
and

required
seCV1Clng
of
these

systems
should
be

carried
out

to
reduce

harmful
emis

sions
to
a
minimum

CRANKCASE
EMISSION
CONTROL

SYSTEM

c

01

Lkf

If
1

TIL
II
tll

1

j

GUuuu
DESCRIPTION

This

system
returns

blow

by
gas
to

both
the
intake
manifold
and
carbure

tor
air

cleaner

The

positive
crankcase
ventilation

p
C
V

valve
is

provided
to
conduct

crankcase
blow
by

gas
to
the
intake

manifold

During

partial
throttle

operation
of

the

engine
the
intake
manifold
sucks

the
blow

by
gas
through
the
P
C
V

valve

Normally
the

capacity
of
the

valve

is

sufficient
to
handle

any
blow

by
and

a
small
amount
of

ventilating
air

4

c
Fresh
air

Blow
by

gas
The

ventilating
air

is
then

drawn

from

the
dust
side
of
the
cadlUretor

air
cleaner

tluough
the
tube

con

necting
carburetor
air
cleaner
to
rock

er
cover
into
the

crankcase

Under
full
tluottle

condition
the

manifold
vacuwn
is

insufficient
to

draw

the
blow

by
flow

tluough
the

valve
and
its

flow

goes
through
the

tube
connection
in
the

reverse
diree

tion

On
vehicles
with
an

excessively

high

blow

by
some
of
the
flow
will

go

through
the
tube

connection
to

carbu

retor
air
cleaner
under
all
conditions

1

Sealtypc
oil
level

gauge

2
Bame

plate

3
Flame
arrester

4
Filler

5
P
C
Y
valve

6
Steel
net

7
Bame

plate

EC716

Fig
EC

l
Crankcase
miaion
control

ay
tem

EC

2
INSPECTION

P
c
V
VALVE
AND

FILTER

Checking
P
C
V
valve
in

accord

ance

with
the

following
method

With

engine
running
at
idle

remove

the

ventilator
hose
from
P

C
V
valve

if
the

valve
is

working
a

hissing
noise

will
be
heard
as
air

passes

through
the

valve

and
a

strong
vacuwn
should
be

felt

immediately
when
a

fmger
is

placed
over
valve
inlet

Replace
P
C
V
valve
and

filter
in

accordance
with
the
maintenance

schedule

VENTILATION
HOSE

1

Check
hoses
and

hose
connec

tions
for
leaks

2
Disconnect
all
hoses

and
clean

with

compressed
air

If

any
hose
cannot
be
free
of

obstructions

replace

Ensure
that
flame
arrester

is

surely

inserted
in

hose
between
air
cleaner

and
rocker
cover

Emission
Control

System

EXHAUST
EMISSION
CONTROL
SYSTEM

DESCRIPTION

EARLY

FUEL
EVAPORATIVE
SYSTEM

E
F
E

DESCRIPTION

OPERATION

REMOVAL

AND
INSTALLATION

INSPECTION

SPARK
TIMING

CONTROL
SYSTEM

DESCRIPTION

SPARK
DELAY
VALVE

Automatic
transmissiom
models

only

INSPECTION

AIR

INJECTION
SYSTEM

DESCRIPTION

OPERATION

REMOVAL
AND
INSTALLATION

DISASSEMBLY
AND

ASSEMBLY

INSPECTION

DESCRIPTION

The
exhaust
emission
control

sys

tem
is

made

up
of

the

following

I

Early
fuel

evaporative
system

2

Spark
timing
control

system

3

Air

injection
system
A
I

S
EC
3

EC
6

EC
6

EC
6

EC
7

EC
7

EC
7

EC
7

EC
7

EC
8

EC
8

EC
8

EC12

EC
14

EC
14

EC
17
CONTENTS

EXHAUST
GAS
RECIRCULATION

CONTROL
SYSTEM
E
G
R

DESCRIPTION

OPERATION

REMOVAL
AND

INSTALLATION

INSPECTION

CATALYTIC

CONVERTER

DESCRIPTION

OPERATION

REMOVAL

AND
INSPECTION

INSTALLATION

FLOOR
TEMPERATURE
WARNING

SYSTEM

DESCRIPTION

OPERATION

REMOVAL

INSTALLATION

INSPECTION
EC
19

EC
19

EC
19

EC
23

EC
24

EC
26

EC
26

EC

26

EC
27

EC
27

EC
27

EC
27

EC

28

EC
28

EC

29

EC

29

7
Altitude

compensator
California

models
4
Exhaust

gas
recirculation
E
G
R

control

system

5

Catalytic
converter
California

models

6
Boost
controlled
deceleration
de

vice
B

C
D
D
As

regards
the
last
two
units
refer

to

the

Engine
Fuel
section

EC
3

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

REMOVAL
AND
INSTAUATION
Emission
Control

System

EC533

Remove

snap
ring
D
and
lock
bolt

@
and
the

following
parts
can
be

detached
from
heat
control
valve

shaft

Key
00

Counterweight
@

TherI
lostat
spring
CID

Coil

spring

@

Note
As

previously
descnoed
heat

control
valv

1
is

welded
to
valve

shaft

@
at
exhaust
manifold
and

cannot
be

disassembled

To
install

reverse
the
removal

pro

cedure

INSPECTION

I
Run

engine
and

visually
check

counterweight
to

see
if
it

operates

properly

1
For
some
time
after

starling

engine
in
cold
weather

counterweight

turns
counterclockwise
until
it

comes

into
contact
with

stopper
pin
installed

to

exhaust
manifold

Counterweight
gradually
moves

down
clockwise
as

engine
warms

up

and

ambient

temperature
goes
higher

around
exhaust
manifold

2
When

engine
speed
is

increased

discharge

pressure
of
exhaust

gases

causes

counterweight
to

move
down

ward
clockwise

3

When
heat

con
trol
valve
is
in
the

full

open
position
coun

terweight

moves
further
clockwise
exceeding
the
1

Snap
ring

2

Lock
bolt

3

Key

4

Counterweight

5
Thermostat

spring

6
Coil
spring

7

Heat
control
valve

8
Valve
shaft

9
Stove
gasket

10
Manifold
stove

11
Heat
shield

plate

Fig
EC
5

Exploded
view
of
E
F
E
stem

position
described
in
1

1
above

and

stops
again
coming
into
con
tact
with

stopper
pin

j

EC246

1

Counterweight

2
S

topper
pin

3
Heat
control
valve

Fig
EC
6

Operation
of
counterweight

when

engine
is
cold

EC246

1

Counterweight

2

Stopper
pin

3
Heat
control

valve

Fig
EC
7

Operation
of
counterw
ight

when
ngine
is
hot

EC
7
2

With

engine
stopped
visually

check
E
F
E

system
for
the

following

items

1
Thermostat

spring
for
dismount

ing

2

Stopper
pin
for
bend
and
count

er

weight
stop

position
for

dislocation

3

Check
heat
control
valve
for

malfunction
due

to
break
of

key
that

locates
counterweight
to

valve
shaft

4
Check
axial
clearance
between

heat
control
valve
and
exhaust
mani

fold
Correct
clearance
is

0
7

to
1

5

mm
0
028
to
0
059
in

5
Check
welded

portion
of

heat

control
valve
and
valve
shaft
for

any

indication
of
crack
or

flaking

6
Rotate
heat
control
valve
shaft

by
a
finger
and
check
for

binding

between
shaft
and

bushing
in

closing

and

opening
operation
of
heat

control

valve
If

any
binding
is
felt
in

rotating

operation
move
valve

shaft
in
the

rotation
direction
several
times
If

this

operation
does

not
correct

binding

condition
it
is
due
to
seizure
between

shaft
and

bushing
and
exhaust
mani

fold
should
be

replaced
as
an
assem

bly

CHECKING
SPARK

TIMING
CONTROL

SYSTEM

DESCRIPTION

The

spark
tirnin
control

system

serves
to
control
the
distributor
vacu

um
advance
under

varying
travelling

conditions
so
as
to
reduce
HC
and

NOx
emissions

This

system
is
installed
on
non

California
automatic
transmission

models

SPARK
DELAY
VALVE

Automatic
transmission

models
only

This

valve
delays
vacuum

spark

advance

during
rapid
acceleration
it

also
cuts
off
the

vacuwn

spark
advance

immediately
upon
deceleration
The

valve
is

designed
for
one

way
opera

tion
and
consists
of
a
one

way
umbrel

la
valve
and
sinlered
steel
fluidic

restrictor

Air

pump
aIr
cleaner

The

air
cleaner
element

is
a
viscous

paper
lype
and

requires
periodic
re

placement
The
air

pump
air

cleaner
is

bolted
to
the
left
front

of
the
hood

ledge

EC778

Fig
EC
14
Air

pump
air
c
leantr

Air

pump

The
air

pump
is

a
two
vane

type
It

has
two

positive

displacement
vanes

which

requires
no

lubricating
seJVice

i

lJ1

I

Jr

l
Emission
Control

System

The
die
cast
aluminwn
air

pump

assembly
attached
to
the
front
of
the

engine
is
driven

by
an
air

pump
drive

belt
A
rotor

shaft
drive
hub

inlet
and

outlet

tubes
are
visible
on
the

pump

exterior
A

rotor
vanes
carbon
shoes

and

shoe

springs
make

up
the

rotating

unit
of
the

pump
The
rotor

located
in

the

center
of
the

pump
is
belt
driven

The

vanes
rotate

freely
around
the

ofT
center

pivot
pin
and
follow

the

circular

shaped

pump
bore
In

the

two
vane

type
the

vanes
form

two

chambers
in
the

housing
Each

vane

completes
a

pumping
cycle
in

every

revolu
tion
of
the
rotor
Air
is
drawn

into
the

inlet

cavity
through
a
tube

connected
to
the

air

pump
air

cleaner

Air
is
sealed
between
the

vanes
and

moved

into
a

smaller

cavity
the

com

pression
area

After

compression
a
vane

passes
the

outlet

cavity

Subsequently
it

passes
the

stripper
and
a
section

of
the

housing
that

separates
the
outlet
and

inlet
cavities
and

again
reaches
the

inlet

cavity
to

repeat
the

pumping

cycle

Carbon
shoes

in
the
slots
of

the

rotor

support
the

vanes

They
are

designed
to

penni
t

sliding
of
the

vanes

and

to
seal
the

rotor
interior

from
the

air

cavities
Leaf

springs
which
are

behind

the

leading
side
of
the
shoes

compensate
for
shoe
abrasion

The
rotor

ring
is

a
steel
bolted
to

the
rotor
end
It

positions
ihe

rotor

and
holds

the
carbon

shoes

The

vane
uses
needle

bearings
All

bearings
have
been

greased

There

are
two

typCg
of

bearing

which

support
the

rotor
Ball

bearing

is

used
for
the
front

one
and
the

needle

bearing
is

used
for
the
rear

j

1
Air

pump
drive

hub

2
HOII

ing

3

Rotor

ring

4
End
cover
with

needle

bearing

5
Vane

6

Carbon
shoe
j

7
Shoe

spring

8

Stripper

9
Rotor
shan

10
Ball

bearing

II
Front

bearing
cover

12

Pulley

13

PuDey
for
air

con
itioner

EC560

Fig
EC

15
Stctionol
view

ofoir
pump
twtrvone

type

EC
IO

Air
control
valve

CalifornIa
models

The
air
control
valve

con
troIs
the

quantity
of

secondary
air
fed

from
the

air

pump
according
to

engine
speed

and

load
condition
and

prevents
ex

cessive

temperature
rise
of
the

cataly

tic
converter

The
construction
is
as
shown
in

Figure
EC
16
The
intake
manifold

vacuum
and
air

pump
discharge
pres

sure

applied
to

the

diaphragm
chamber

actuate
the

valve
which
is

coupled
to

the

diaphragm
and
control
the

quanti

ty
of

secondary
air
to
be
fed
into
the

exhaust
manifold
in

response
to
the

engine
condition

c
From

air

pump

To

carburetor

air
cleaner

lr

J

EC291

Fig
EC
16
Air
control
valve

Anti
backfire
valve

This

valve
is

con
trolled

by
intake

manifold
vacuum
to

prevent
backfire

in
the

exhaust
system
at

the
ini

tial

period
of
deceleration

At
this

period
the
mixture
in
the

intake
manifold
becomes
too

rich
to

ignite
and
burn
in
the

combustion

chamber
and
burns

easily
in
the
ex

haust

system
with

injected
air
in
the

exhaust
manifold

The
anti
backfire
valve

provides
air

to
the
intake
manifold
to
make
the

air
fuel
mixture
leaner
and

prevents

backfire

A
schematic
drawing
of
the
anti

backfire
valve
is
shown
in

Figure

EC
17

The
anti
backfire
valve
inlet
is

con

nected
to
the
air
cleaner
and
the

outlet

to
the
intake
manifold

Th
correct
function
of
It
jS
valve

reduces
hydrocarbon
emission

during

aeceleration

If
the
valve
does
not
work

properly

unburned
mixture
will
be

emitted
Emission
Control

System

from
the
combustion
chambers
and

burns
with
the
aid
of
high

temperature

and

injected
air

which
causes
backfire

I
Tointake

c
manifold

vacuum

I

L

AirdisChaJ1le

I

to
mtake

manifold
From
air

cleaner

ECQ69

Fig
EC
11
Anti
back
ir
valve

Check
valve

A
check
valve
is
located
in
the
air

pump
discharge
lines
The
valve

pre

ven
ts
the
backflow
of
exhaust
gas

which
occurs
in

one
of
the

following

cases

1
When

the
air

pump
drive
belt

fails
2
When
relief
valve

spring
fails

Construction
is

shown
in

Figure

EC

18

F
rom

m

pump

1

Spring

2

Rubber
valve

3

Seat
Secondary
air

Exhaust

gas

EC292

Fig
EC
1B
Check
valve

AIr

InJaction
Into
axhaust

port

The

secondary
air

fed
from
the
air

pump
goes
through
the

check
valve
to

the
air

gallery
where
it
is
distributed
to

each
exhaust

port
The

secondary
air

is
then

injected
from
the
air

injection

nozzle
into

the
exhaust

port
near
the

exhaust
valve

n

L
y

r

V

Air
pump
relief
valve

The
air

pump
relief
valve

controls

the

injection
of
the

secondary
air
into

the
exhaust

system
when
the

engine
is

EG
11
3
I
Air

gallery

2

Exhaust
port

3
Air

jnjection
nozzle

4
Exhaust

manifold

EC293

Fig
EC
19
Air
injection
into
exhaust

port

running
at

high
speed
under
a

heavily

loaded
condition
It

accomplishes
the

following
functions
without

affecting

the

effectiveness
of
the
exhaust
emis

sion
control

system

Minimizes
exhaust

gas
tempera

lure
rise

2
Minimizes

horsepower
losses
re

suiting
from
air

injection
into
the

exhaust

system

3
Protects

pump
from
excessive

back

pressure

The
air

pump
relief
valve
is
installed

as
shown
in

Figure
EC

20

The

secondary
air
is

discharged

from
the
air

pump
relief
valve

to
the

dust
side
of
the
carburetor
air
cleaner

To
carburetor

air
cleaner

Secondary

air

To
carburetor

air

cleaner

J
erCOndary

r

r

EC294

Fig
EC
20
Air

pump
relief
valve
Emission
Control

System

Emargency
air
retial
valve

E
A
R
Valve

California
models

The

emergency
air
relief
valve
con

trols
the

quantity
of
secondary
air

fed

from
the
air

pump
according
to

load

condition
and
it

discharges
the
see

ondary
air
into
the

atmosphere
to

prevent
overheating
of
the

catalytic

converter

The

emergency
air
relief
valve
con

sists
of
a

diaphragm
a

spring
and

a

valve
which
is

coupled
to

diaphragm

1

Diaphragm

2

Val

3

Spring

4

Diaphragm
chamber

EC536

Fig
EC

21

mergency
air

relief
valve

OPERATION

As
mentioned

previously
there

are

two

types
of
Air

Injection
Systems

A
I

S
a

non
California

type
and
a
California

type
The
California
stand

ard

type
includes
a

system
which

controls

injection
of

secondary
air

so

as
to
assure

proper
function
of
the

catalytic
converter
and
a

system

which
controls
the

supply
of
second

ary
air
to

prevent
abnormal

tempera

tUfe
rise
in
the

catalytic
converter

The
A
I
S
consists
of
the

following

systems

L
A

system
which
allows

injection

of

secondary
air
into
the
exhaust

port

2
A

system
which

bypasses
sec

ondary
air

from
the
air

pump
relief

valve

to
the

carburetor
air

cleaner

during

high
speed
engine
operation

3
A

system
which

supplies
air

from

the
carburetor
air
cleaner

to
the
intake

manifold

by
means
of
the
anti

backfire

valve
so
as
to

prevent
after
fire

during

deceleration

4
A

system
which

controls

injection

of
the

secondary
air

by
means
of
the

air

control
valve

so
as
to
maintain
the

catalytic
converter
at
an

optimum

temperature
level
under

lightly
loaded

condi
tions

Califomia

type
only

5
A

system
which
controls
the

sup

ply
of

secondary
air

through
the
emer

gency
air

relief
vilve

io
pfevent
ab

normal

temperature
rise
of
the

cataly

tic

converter

California

type
only

A
I

S

operation
is

as
follows

I

I

t

1
r

9

I
Air

pump
6

Check
valve

I
0
L
2
Air

pump
air
deaner
7
Air

gallery
pipe

3
Air

relief
valve
8
Injection
non
e

r
4
Air
cleaner
9

Exhaust
manifold

5

Carburetor
10

Anti
backflIe
valve

EC179

Fig
EC
22
Non

California
type
A
I
S

EC
12

9
From
air

pump

l

h
1

Not
actuated

REMOVAL
AND

INSTALLATION

Air
p
mp
sir
cleaner

Remove
air
hose

then
detach
air

cleaner

from

hoodledge
Air
cleaner

element
and
Ii
r
deancr
lower

body
are

built
into
a
unit
construction

Replace

air
cleaner
clcl

nen
and

lower

body
as

an

assembly

J

J

tt
c

t
o

J

EC
323

Fig
EC
26
Replacing
oir
cleaner

element

Air

pum

Remove
air
hoses

from
air

pump

2
Loosen
air

pump
adjusting
bar

mounting
bolts
and
air

pump
mount

ing
bolts
then

remove
air

pump
drive

bell

3
Remove
air

pump
pulley

4
Remove
air

pump
from
bracket

Air
control
valve

California
models

l
Disconnect

air
hoses
and
a
vacu

um
hose
from
air
control
valve

2
Remove
air
con
trol
valve
from

bracket

E
A

R
valve
California
modela

Remove
vacuum

pipe
and
air

hose

and
dismount
E

A
R
valve
Emission
Control

System

o

jJ
To

Intake
mamfold

rF
vacuum

r

To
air

cleaner

From
air

pump

EC781

Fig
EC
27
Locotion

of
E
A
R
wive

Antl
backflravalve

Disconnect
air
hose
and
vacuum

hose
from
anti
backfire
valve

Check
valve

Disconnect
hose
and
remove
check

valve
from
air

gallery
pipe

Air

ganery
pIpe
andinJactlon

nozzles

It
is

very
difficult
to
remove
the
air

gallery
from
the
exhaust
manifold

without

bending
the

pipe
which
could

result
in
fractures
or

leakage
There

fore

removal
of

the
air

gallery
pipe

and

injection
nozzles
should
be
under

taken

only
when

they
are

damaged

I
Lubricate
around
the

connecting

portion
of
air

injection
nozzle
and
air

gallery
with

engine
oil

2
Hold
air

injection
nozzle

hexagon

head
with
a

wrench
and
unfasten
flare

screw

connecting
ait

gallery
to

injec

tion
nozzle
Remove
air

gallery

EC
14
To
intake

manifold

vaCUl
lm

r

Y

4
9
Gf

T

I
To

air
cleaner

I

Actuated

EC299

Fig
EC
25

Operation
of
air
control
value

Notes

a

Apply
engine
011
to
rews
several

times
during
above

work

b
Be
atreful
not
to

damage
other

parts

3
Unfasten
air

injection
nozzle

from

cylinder
head

applying
engine
oil

to
screwed

portion
several
times

4

Check
air

gallery
and
nozzle
for

fractures
or
leakage
Clean
air

injection

nozzle
with
a
wire
brush

5

At
time
of
installation
hold
air

injection
nozzle

hexagon
head
with

a

wrench
and

tighten
air

gallery
flange

screw
to
a

torque
of
5
0
to
5
9

kg
m

36
to
43
ft
lb

6
Check

cylinder
head
air

injection

nozzle
and
air

gallery
for
leaks
with

engine
running

Air

pump
relief
vslve

Loosen
carburetor
air
cleaner

mounting
sc
ews
and

remove
air

pump
relief
valve

InstallatIon

Install
in
the

reverse
order
of
reo

moval

DISASSEMBLY
AND

ASSEMBLY

Disassembly
of
air
pump

1
Remove
four

pulley
drive
bolts

and
remove

pulley
from
hub

2

Secure
air

pump
drive
hub
in

a

vise

as
shewn
in

Figure
EC

28
and

remove
four
end
cover
bolts