1979 DATSUN 210 ECU

following
functions
without

affecting

the

effectiveness
of
the

exhaust
emis

sion
control

system

Minimizes
exhaust

gas
tempera

ture
rise

2
Minimizes

horsepower
losses
reo

sulting
from
air

injection
into
the

exhaust

system

3

Protects

pump
from
excessive

back

pressure

To
carburetor

air
cleaner

Secondary

ir

Not
actuated

To
carburetor

air
cleaner
J

l
Secondary

sir

Actuated

EC294

Fig
EC
18
Air

Pump
Relief
Valve

c
A
C
valve

Californiamodels

The
C
A
C
valve

controls
the

quantity
of

secondary
air
fed
from
the

air

pump
according
to
the
load
condi

tion
and
it

discharges
the

secondary

air
into
the

atmosphere
to

prevent

overheating
of

the

catalytic
converter

This
valve
is

operated
by
intake

manifold
vacuum

and
air

pump
dis

charge

pressure
When
intake
manifold

vacuum
is

small
or
in

the

high
load

range
the
No
2
valve

opens
when
it
is

great
or
in

the
low
load

range
the
No

I

valve

opens
If
air

pump
discharge

pressure
is

large
or
the

engine
is

running
at
a

high
speed
the
No
3

valve

opens
admitting
the
air

pump

discharge

pressure
to
the
No
2
dia

phragm
chamber
of
the
C

A
C
valve
mission
Control

System

and

opening
ihe
No
i
valve
At
this

point
the
No
2
valve

serves
as
a

relief

valve

F
111

air
pump
No
3

valve

EC787

Fig
EC
19

C
A
C
Valve

I
Engine
in
low

speed
and

light
load

When
the

engine
is

operating
under

these
conditions
intake
vacuum
is

high
The
No
2
valve
unitized

with

the
No
I

diaphragm
is

lifted

by
the

intake

manifold
vacuum

pushing
up

the
No
I

valve
These
valves
will
then

stop
at
a

position
where
a

balanced

condition
exists
between
air

pump

discharge
pressure
an
d

spring
tension

acting
on
the

No
I

and
No

2
valves

The

No
2

jiaphragm
however
does

not
move
due

to
low

engine
speed
low

air

pump
discharge
pressure
and

spring

tension

acting
on
the
No

3
valve
For

this
reason
these
valves
are

brought
to

a
balanced
condition

To
intake
manifold

t

i

l

3

Spring

4

ValveNo
3

5
Di

phragm
No
I
I

@

6

Spring

7

Valve
No
1

8
Valve
No

2

EC683

Fig
EC

20

Operation
of
C
A
C

Valve

1

2

Engine
in

low

speed
and

heavy
load

EC12
Wheo
the

engine
is

operating
under

these
cooditions

intake
manifold

vacuum
is
low
and

all
valves

are

balanced

t
To

intake

manUol

U

E

ii

ji
j

Ii
5

LL

jj

Ii
JI

l
Jij

ulJC

1t

To

atmosphere
EC685

Fig
EC
21

Operation
of
C
A
C

Valve
2

3

Engine
in

high
speed
and

middle

load

When
the

engine
is

operating
under

these
conditions
intake

manifold

vacuum
lies

midway
between
1

and

2

above
The
No
3
valve

moves
to

the
left

because
of

high
air

pump

discharge
pressure

To

intake
manifold

t

L

J

f
E

bt

I
5

tfi
11

I

LJr

To

tmg
J
j
1

EC
4

Fig
EC
22

Operation

of
C
A
C

Volve
3

REMOVAL
AND

INSTALLATION

Air
pump
air
cleaner

Loosen

nuts

securing
air

pump
air

cleaner
to

bracket
then
detach
air

cleaner
from
bracket

Air
cleaner
filter

and
air
cleaner
lower

body
are
built

into

a
unit
construction

Replace
air

cleaner
filter
and
lower

body
as
an

assembly

EC149A

Fig
EC

23

Removing
Air
Cleaner

Filter

Air

pump

1
Remove
air

hoses
from

air

pump

2
Remove
air

pump
pulley

3
Loosen
air

pump
adjusting
bar

mounting
bolts
and
air

pump
mount

ing
bolts
then
remove
air

pump
drive

belt

4
Air

pump
assembly
can
be
taken

out
from
bracket

5

Installation
is
in

the
reverse
se

quence
of
removal

Fig
EC
24

Removing
Air

Pump

Check

valve

1
Disconnect
air

hose
from
check

valve

2

Remove
check
valve
from

engine

cylinder
head

3

Installation
is
in

the
reverse
se

fluence
of
removal
Emission

Control

System

EC151A

Fig
EC
25

Removing
Check
Valve

A

B
valve

A
B
valve
is

located
at
the

rear
side

of
air

cleaner
Remove
air

hoses
and

vacuum
tube
A
B
valve
can
then
be

taken
out

EC152A

Fig
EC
26

Removing
A
B
Valve

Air

pump
relief
valve

Non
California
models

I

Loosen

clamp
of
air

hose
and

disconnect
air

hose
from
relief
valve

EC
13
2
Remove
screws

securing
relief

valve
to
air

cleaner
Relief

valve
can

then

be
taken

out
easily

3
Installation
is
in
the
reverse
se

quence
of

removal

EC153A

Fig
EC
27

Removing
Air

Pump

Relief
Valve

C
A
C
valve

California
models

C
A
C

valve
is
located
beneath
con

trol

device
bracket

Remove

clamps
and

disconnect

air

hoses
and
vacuum
tube

2

Remove
screws

securing
C
A

C

valve
Air
control
valve

can
then
be

taken
out

easily

3
Installation
is
in
the

reverse
se

quence
of
removal

EC154A

Fig
EC
28

Removing
C
A
C
Volvo

DISASSEMBLY
AND
ASSEMBLY
OF
AIR
PUMP
Emission

Control

System

Bearing

kit

Disassembly

I

Remove

pulley
drive
bolts
and

remove

pulley
from

hub

2

Secure
air

pump
drive
hub
in
a

vise
and

remove
end
cover
bolts

CAUTION

Never

clamp
on
the

aluminum
hous

ing

EC302

Fig
EC
30

Removing
Cover

3
Remove
end
cover

by

carefuDy

tapping
around
dowel

pin
wi
th

a

plas

tic
mallet
and
lift

up
straight
Vane
kit

4
Put

match
marks
0
on

rotor

ring
and

side
of

rotor
to

ensure
correct

reassembly
and

remove

screws
that

retain
rotor

ring
to

rotor

using
a

Hexagon
Wrench
STl98l0000

Note

a

Generally
match

marks
are
indi

cated
on

both
rotor

ring
and
rotor

by
the

manufacturer

Ee111

Fig
EC
31

Removing
Rotor

Ring

b

Discard
screws
which
were
re

moved

Always
use
new
ones

when

installing

EC
14
EC562

Fig
EC

29

Component
of
Air

Pump

5
Remove

vanes
from

rotor

Fig
EC

32

Removing
Vanea

6
Remove
carbon

shoes
and
shoe

springs
from
rotor

using
needle

nose

pliers
or
tweezers

Note

Carbon
shoe
A
is
I
mm

0
04

in

wider

than
8
Do

not
confuse
them

Fig
EC
33
R

moving
Shoe

Springs

If

replacement
of
fron
t

bearing
is

necessary
proceed
as
follows

7
Remove
air

pump
drive
hub

with

standard

puller

8
Remove
screws

securing
front

bearing
cover
in

place
and

detach

bearing
cover

9

Support
the
rear
end
face

of
air

pump
housing
with
Rotor

Adapter

STI
9890000

Drive
rotor
out
by

push

ing
rotor
shaft
with

Bearing
Pressing

Tool
STI
9940000

STl9940000

JJr

STl9890000

EC303

Fig
EC
34

Removing
Rotor

Shaft

10

Support
the
fron
t
end
face
of

housing
with

Bearing
Stand

STI9930000
Attach

Bearing
Driver

STI
9910000
to
front

bearing
on
the

inside
of
air

pump
housing
and

press

out
I

STl9910000

1

c

R
9930000

II
EC304

Fig
EC
35
R

mouing
Ball
B

aring
Emission
Control

System

II

Keep
disassembled

parts
in

order

Assembly

Front

bearing

Support
the

rear
end
face
of
air

pump
housing
with
Rotor

Adapter

STI
9890000
Press
front

bearing
into

place
with

a

press
and

Bearing
Pressing

Tool
STI
9940000

I
I

J

j
71
EC306

Fig
EC

36

Pre88ing
Ball

Bearing

2

Bearing
cover

T

ighten
bearing
cover

securing

bolts

@
Tightening
torque

Bearing
cover
securing
bolts

0
1
to
02

kg
m

0
7
to

1
4
ft
Ib

3

Rotor
shaft

Support
the
in
ard
bottom
of
ro

tor
with
Rotor

Staild
STI
9920000

Press
rotor
into

place
with
a

press

and

Bearing
Driver
STI9910000
until

the

stepped
portion
of
rotor
shaft

touches
front

bearing
inner

race

t
7

STl9910000

STl9920000

i
I
EC307

Fig
EC
37

Pressing
Rotor

Shaft

Note

a
Be

sure
to
drive
front

bearing
inner

race
in

EC
15
b
After
rotor
is
installed
in

place

ensure
that
the

rotor
end
is

posi

tioned
helow
the
end

face
of
air

pump
housing

Position
of
rotor
end
below
air

pump
housing

0
050
to
0
150

mm

0
0020
to
0

0059
in

4
Air

pump
drive
hub

Support
the

inward
bottom

of
ro

tor
with
Rotor
Stand
STI
9920000

Press
drive
hub
into

place
with

a

press
and

Bearing
Driver
STI99l0000

until
the
end

face
of
drive
hub
touches

front

bearing
inner
race

H

STl99
10000

EC30B

Fig
EC

38
Pre

sing
A
ir

Pump
Drive

Hub

5

Carbon
shoe

I
Place
air

pump
drive
hub
in
a

vise

2
Clean

carbon
dust
etc
from

shoe

grooves

3

Align
rotor

with

housing
prop

erly
Then
insert
carbon
shoes
into

place
noting
their
directions

EC5
0

Fig
EC

39
Install
Carbon
Sho

Note

a
Carbon

sh
A

is
I
mm
0
04
in

wider
than
B
Do

not
confuse

them

b
If
carbon
shoes
are

exposed
beyond

the
rotor
end
face
remove
carbon

shoes
and
clean
shoe

grooves
Reas

semble
carbon
shoes

6

Vane

1
Pack

vane

bearing
with

high

melting

poinf
grease
MIL
G
3S45
A

Es

o
ANDOK260
or

equivalent
and

insert

dummy
shaft
into
the
vane

bearing

STl9900000

EC563

Fig
EC
40

Va
Assembly

2
Install
vane
in

place
on
rotor

uMng
Dummy
Shaft
STl9900000
as
a

guide

Note
The
woes

may

require
6
to
16

km
4
to
10
miles
wear
in
running

time
In
the
event

a

slight
squeaking

still
remains
drive
the
car

about
64

to
80

km
h
40
to
SO
MPH
In

most

cases
6

to
16
km
4
to
10

miles
will
be
sufficient
for
wear
in

7

Shoe

spring

Place
shoe

springs
in

deeper
groave

of
shoe

11

I

11

1

EC123

Fig
EC
4I
Ins

tolling
Shoe

Spring

Note
When

installing
a

shoe

spring

make
sure
that
the
outward
bend

ing
side
faces
in
shoe
and
that
both

ends
of

sJlri
face
in
the
wall
of
Emission
Control

System

shoe

groove
6e
Sure
to

push
spring

in

SO
that

spring
end
face
is
flush

with
rotor

8
Rotor

ring

Install
rotor

ring
by
correctly

align

ing
the
rear
end
face
of
rotor
with

the

on

mark
in
rotor

ring
and

tighten

screws
with

Hexagon
Wrench

ST
98
10000

l
l
Tightening
torque

Rotor

ring
screw

0
5
to
0

7

kg
m

13

6
to
5
1
ft
lb

Fig
EC

42
Installing
Rotor

Ring

9
Removal
of

dummy
shaft

CarefuDy
withdraw

dummy
shaft

from
vane

10
Vane
shaft

Pack
rear

bearing
with

high

melting

pain
t

grease
MIL
G
3S45
A

Esso
ANDOK
260
or

equivalent

Apply
thin

coating
of

grease
to
vane

shaft
and

rotor
ring
and
insert

vanf

shafi
into
its

bearing

Note

a

Do
not

apply
an
undue
stress
to

vane
shaft
when

inserting

b
If
two
vanes
are
dislocated
when

inserting
vane
shaft

correctly
align

Yanes

by
inserting
dummy
shaft

Then
draw
out

dummy
shaft
and

insert
vane
shaft

c
When
wear
occurs
on

vane
shaft
or

when

replacement
of
rear

bearing
is

necessary
replace
rear
rover
assem

bly

J
I

End
cover

Position
end

cover
in

place
Snugly

tighten
the
bolt
close
to
the
dowel

Then

tighten
end
cover

bolts

EC
t6
l
l
Tighteningtnrque

End
cover
bolts

0
7
to
0
9

kg
m

5
1

to
6
5
ft
bl

EC302

Fig
EC
43
lnstolling
End
Cover

12

Pulley

Tighten

pulley
securing
bolts

Tightening
torque

Pulley
securing
bolts

0
75

to
0
90

kg
m

5
4

to
6
5
ft

Ib

INSPECTION

The
following

procedures
are
re

commended
for

checking
and
or

as

certaining
that
the
various

components

of
the

exhaust
emission
control

system

are

opera
ting
properly

The

engine
and
all

components

mu
t
be
at
normal

operating

tempera

tures
when
the
tests
are

performed

Prior
to

performing
any
extensive

diag

nosis
of
the
exhaust
control

ystem
h

must

be
determined
that
the

engine
as

a
unit
is

functioning
properly

Air

injection
s

stem
hoses

Check
air

system
hoses
for
loose

connections
cracks
or
deterioration

Retighten
01

replace
if

necessary

Air

pump

I

Operate
engine
until
it
reaches

normal

operating
temperature

2

Inspect
all
hose
hose
connec

tions
and
air

gaDery
for
leaks
and

correct
if

necessary
before

checking

air

injection

pump

3
Check
air

injection
pump
belt

tension
and
adjust
to

specifications
if

necessary

4

Plug
up
air

discharging
hose

from

C
A
C
valve
California
models

y

o

EC144A

Fig
EC
44

Plugging
C
A

C
Value

Air

Discharging
Hose

California
model

S

Disconnect
air

supply
hose
at

check
valve

6
Insert

open
pipe
end
of
Air

Pump

Test

Gauge
Adapter
STl9870000
in

air

supply
hose

Clamp
hose

securely

to

adapter
to

prevent
it
from

blowing

out
Position
adapter
and
test

gauge
so

that
air
blast
emitted

through
drilled

pipe
plug
will
be

harmlessly
dissipated

7
Install
a
tachometer
on

engine

With
the

specified
engine
speed
ob

serye
air

pressure
A

produced
at
test

gauge

Air

pressure
A

More
than

100

mmHg
3
94

inHg

at
2
600

rpm

I

jff

100
m

Hg

f1

3
94

mHg

I

EC145A

Fig
EC
45

Testing
Air

Pump

8
If
air

pressure
does
not
meet

above

specifications
proceed
as

follows
Emission

Control

System

Non

California
models

1
Repeat
2

and
3
above

2
With

engine
speed
at
1
500

rpm

disconnect
tube

from

adapter
and

close
hole
of

test

gauge
with

finger
If

a

leaking
sound
is
heard

or

leaking
air

is
felt

by
finger
at
relief
valve
relief

valve
is

malfunctioning
Relief
valve

should
be

replaced
or

repaired

3
If
air

injection
pump
does

not

meet
minimum

requirement
of

pres

sure
test
it
should
be

repaired

California
models

Disassemble
the
air

pump
and
re

pair
it

Check
valve

Warm

up
engine
thoroughiy

2
Disconnect

hose

leading
to

check

valve
from
air

hose
connector

3
Check
hose

opening
for

any
indi

cation
of
exhaust

gas
leaks
If
leaks

are

detected

replace
check
valve

4
Race

the

engine
lightly
at
about

2
000

rpm
and
then

return
it
to

idling
Visually
check
the
hose
for

any

indication
of
exhaust

gas
leaks

before

the

engine
returns
to

idling
speed
If

leaks
are
detected

replace
check
valve

EC146A

Fig
EC
46

Checking
Check
Valve

Air
pump
relief
valve

After

completing
inspection
of
air

pump
check
air

pump
relief

valve
in

the

following
steps

I
Disconnect
hoses

leading
to
check

valve
and
air
control
valve
from
air

hose

connector
and
install

blind
c

p

to
the
connector

2
With

engine
running
at
about

3
000

rpm
under

no
load

place
your

EG
7
hand
on
the
air
outlet
of
air

pump

relief
valve
to

check
for

discharged
air

If

no
air
is
felt

replace
the

air

pump

relief
valve

G

EC575

Fig
EC
47

Checking
Air

Pump

Relief
Valve

Anti
backfire
valve

A
B

valve

I
Warm

up
engine
thoroughly

2
Disconnect
hose
from
air

cleaner

and

place
a

finger
near
the

outlet

3
Run

engine
at
about
3

QOO
rpm

under
no

load
then

quickly
return
it

to

idling
If

you
feel
a

pull
or
suction

force
on

your
finger
the
anti
backfire

valve
is

functioning
normally
If

no

suction
is

felt

replace
the
anti
backfire

valve

EC768

Fig
EC
48

Chocking
Anti

backfire

Valve

C
A
C
valve

California
models

I

Make
sure
that

C
A
C

valve
vacu

um

hose
and
air

hose
are

not
cracked

2
Warm

up
engine
throughly

3
With

engine
at
idle

place
your

fmger
over

relief
hose

opening
to

check
for

presence
of
air

4

With

engine
idling
disconnect

vacuum
hose
at
C
A

C
valve

Then
make

sure
that
air
is

discharg

ed
from

C
A
C
valve

C

A
C
valve
is

functioning

properly

if
air
is

discharged
from
it

Air
Induction
v
lve
filter

The
air
induction
valve
filter
is

installed
at
the
dust
side
of
the
air

cleaner
It

purifies
secondary
air

to
be

sent
to
the

exhaust
tube
The
fIlter

element
should
be

replaced
periodical

ly
in
accordance
with
the
Maintenance

Schedule

EC921

Fig
EC
54
Air
Induction
Valve

Filter

Antl
beckflre
v
lve
A
B
v
lve

Tltis
valve
is

controlled

by
intake

manifold
vacuum
to

prevent
backfire

in
the

exhaust
system
at
the
initial

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

If

the
valve
does
not
work

properly

unburned
ntixture
will
be

emitted

from

the
combustion
chambers
and

burns
with
the
aid
of

high
temperature

and

injected
air
which

causes
backfrre

To
intake

manifold

vacuum

To
intake

manifold

From
air

cleaner

EC069

Fig
EC
55
Anti

backfire
Value
Emission
Control

System

Air
Induction
Into
exhaust

port

The

secondary
air
fed
from
the
air

induction
valve

goes
through
the
check

valve
to
the
air

gallery
in

the

cylinder

head
It
is
then

distributed
to

each

exhaust

port
and

injected
near
the

exhaust
valve

I
Air

gallery

2
Exhaust

port

3
Exhaust
manifold

EC316

Fig
EC
56
Sectional
View

of

Exhaust
Port

REMOVAL
AND

INSTALLATION

Air
Induction
valve
and
filter

Remove
the
screws

securing
the

valve
and
filter
to
the
air

cleaner
body

The
air
induction
valve
and
valve
filter

can
then
be
taken

out

easily
Installa

tion
is
in
the
reverse

sequence
of

removal

EC922

Fig
EC
57

Removing
Air
Induction

Valve
and
Filter

EC
19
Air
Induction

pipe

Loosen
out
a

nut
securing
the

pipe

to

the

engine
cylinder
head
At
the

same
time
remove
the
screws

securing

the
bracket
and
rubber
hose

clamp

The
air
induction

pipe
can
then
be

taken
out
Installation
is
in
the
reverse

sequence
of
removal

Fig
EC
58

A
B
valve

The
A
B
valve
is
located
at
the

rear

side
of
the
air
cleaner
Remove

the
air

hoses
and
vacuum
tube

The
A
B
valve

can
then
be

taken

out
Installation
is
in
the

reverse
se

quence
of
removal

EC152A

Fig
EC
59

Removing
A
B
Valve

INSPECTION

Preliminary
Inspection

Check
hose
for
looseness

flatting

damage
or

faulty
connections
and

each

part
for

proper
installation
If

necessary

replace

Air
Induction
valve
and
filter

I
Disconnect
air
induction
hose
at

air
induction

pipe
side
Suck
or
blow

hose
to
make
sure
that
air

flows

only

on
the
air

induction

pipe
side

1l

I

I

1J

1

Diaphragm
spring

2

Diapliragm

3
Valve
shaft

4
Valve

5
ValVe

seat

6
Valve
chamber

EC231

Fig
EC
64
E
G
R
Control
Value

Thermal
vacuum
valve

2

port

type

FU
and
Canada
models

The
2

port

type
thermal
vacuum

valve
is
mounted
on
the

engine

thermostat

housing
It

detects

engine

coolant

temperature
by
means
of
a

built
in

bi
metal
and

opens
or
closes

the
vacuum

passage
in
the

thermal

vacuum
valve

When
the
vacuum

passage
is

open

the

carburetor
vacuum

signal
is

applied

to
the

diaphragm
of
the
E
G
R
con

trol

valve
to
actuate
the

taper
valve

connected
to
the

diaphragm

1

Spring

2

Bi
metal

3
O

ring

EC232

Fig
EC
65
Thermal
Vacuum
Valve

2

port
type
Emission
Control

System

Thermal
vacuum
valve

3

port
type

U
S
A
models

except

FU

model

The
3

port
type
thermal

vacuum

valve
is
located

on
the
rear

end
of
the

cylinder
head

It

defects

engine
coolant

tempera

ture

by
means
of
wax

expansion
and

opens
or
closes
the
air

passage
from

the
air

cleaner

When

the
air

passage
is
closed
the

carburetor
vacuum
signal
is

applied
to

the

diaphragm
of
the
E
G
R

control

valve
to
actuate
the

taper
valve
con

nected
to
the

diaphragm
This
valve
is

also
co
used
as
a

component
for
the

Spark
Timing
Control

System

JiI2
To
air
cleaner

From
B
P
T

valve

From
distributor

EC156A

Fig
EC
66
Thermal
Vacuum
Valve

3

port
type

B
P
T
valve

The
B
P

T
valve
monitors
exhaust

pressure
to
activate
the

diaphragm

controlling
intake

manifold
vacuum

applied
to
the
E
G
R

control
vaNe
In

other
words
the

amount
of
recirculat

ed
exhaust

gas
vari

s
with
the

position

of
the
E
G
R

valve

regulated
by
the

operating
condition
of
the

engine

EC
23
To
E

G
R

control
valve
Vacuum
nal
Curce

Air
bleed
1

Exhaust

pressure

EC310A

Fig
EC
67
B
P
T
Value

REMOVAL
AND

INSTALLATION

E
G
R
control
valve

I
Disconnect

vacuum
hose
and
re

move
nuts

securing
E
G
R

control

valve
to
E

G
R

passage
The
E

G
R

control
valve

can
then
be
taken
out

Fig
EC

68

Remouing
E
G
R

Control
Valve

CAUTION

Pay
attention

not
to

give
damage
to

packing
of
E
G
R

control
valve

2

Installation
is
in

the
reverse
se

quence
of
removal

Note
In

installing
new
E
G
R

control

valve
confirm
that

the
model

num

ber
and

identification
marks
at

the

top
of
valve
are

as
follows