DATSUN 210 1979 Service Manual
Page 131 of 548
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
Page 132 of 548
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
Page 133 of 548
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
Page 134 of 548
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
Page 135 of 548
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
Page 136 of 548
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
Page 137 of 548
Note
When
tho
vaCUUm
hose
is
dis
connected
plug
it
up
or
engine
will
stumble
EC
47A
FiJ
Fig
EC
49
Disconnecting
Vacuum
Hose
from
C
A
C
Valve
5
Connect
hand
operated
vacuum
pump
in
place
and
manipulate
it
in
order
to
apply
a
pressure
of
2oo
to
250
mmHg
7
87
to
9
84
inHg
to
C
A
C
valve
Increase
engine
speed
to
3
000
rpm
and
confIrm
that
no
air
leaks
from
C
J
C
valve
Fig
EC
50
Checking
C
A
C
Valve
1
6
With
the
above
condition
discon
nect
air
hose
at
check
valve
and
plug
it
up
At
this
point
confirm
the
air
leaks
from
C
A
C
valve
ECl48A
Fig
EC
51
Checking
C
A
C
Volve
2
Emission
Control
System
7
If
teshesults
satisfy
3
4
5
and
6
the
C
A
C
valve
is
properly
function
ing
AIR
INDUCTION
SYSTEM
A
I
S
DESCRIPTION
The
air
induction
system
A
1
s
is
adopted
on
the
FU
model
and
Canada
models
and
is
designed
to
send
see
ondary
air
to
the
exhaust
tube
utiliz
ing
a
vacuum
caused
by
exhaust
pulsa
tion
in
the
exhaust
tube
Air
inductIon
valve
A
reed
valve
type
check
valve
is
installed
in
the
air
cleaner
When
the
exhaust
pressure
is
below
atmospheric
pressure
negative
pressure
secondary
air
is
sent
to
the
exhaust
manifold
When
the
exhaust
pressure
is
above
atmospheric
pressure
the
reed
valve
prevents
secondary
air
from
being
sent
back
to
the
air
cleaner
EC
t8
The
exhaust
pressure
in
the
exhaust
tube
usually
pulsates
in
response
to
the
opening
and
closing
of
the
exhaust
valve
and
it
decreases
below
atmos
pheric
pressure
periodically
If
a
secondary
air
intake
is
opened
to
the
atmosphere
under
vacuum
con
ditions
secondary
air
can
be
drawn
into
the
exhaust
tube
in
proportion
to
the
vacuum
Therefore
the
air
induction
system
A
I
s
reduces
CO
and
HC
emissions
in
exhaust
gases
operatiug
the
same
as
the
air
injection
system
A
I
s
The
system
cpnsistsof
an
air
in
tJctio
valve
a
filter
an
A
B
valve
and
hoses
fl
V
t
5
1
Air
ind9ction
valve
2
Air
c
eancr
3
Carburetor
4
Exhaust
manifold
5
Anti
obRcldlre
valve
EC919
Fig
EC
52
Ai
Induction
SYltem
1
Reed
valvo
2
Stopper
EC920
Fig
EC
53
Air
Induction
Val
Page 138 of 548
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
Page 139 of 548
EC924
Fig
EC
60
Checking
Air
Induction
Valve
2
Check
air
induction
valve
reed
valve
for
binding
or
damage
At
the
same
time
check
filter
for
damage
or
plugging
If
necessary
replace
Filter
should
be
replaced
periodically
in
ac
cordance
with
Maintenance
Schedule
Emission
Control
System
1
Air
induction
valve
filter
2
Air
induction
valve
EC925
Fig
EC
6I
Checking
Air
Induction
Valve
and
Filter
Anti
backfire
valve
A
B
alve
I
Warm
up
engine
thoroughly
2
Disconnect
hose
from
air
cleaner
EC
20
and
place
aflriger
near
tneoutlet
3
Run
engine
at
about
3
000
rpm
under
no
load
then
quickly
return
it
to
idling
If
you
feel
a
pull
or
suction
force
on
your
finger
the
anti
J
ackfire
valve
is
functioning
normally
If
no
suction
is
felt
replace
the
anti
backfire
valve
eC76S
Fig
EC
62
Checking
Anti
bock
ire
Valve
Page 140 of 548
Emission
Control
System
EXHAUST
GAS
RECIRCULATION
E
G
R
CONTROL
SYSTEM
DESCRIPTION
to
lower
the
spark
flame
temperature
during
combustion
This
results
in
a
reduction
of
the
nitrogen
oxide
NOx
content
in
the
exhaust
gas
When
the
E
G
R
control
valve
is
open
some
of
the
exhaust
gas
is
led
from
the
exhaust
manifold
to
the
E
G
R
chamber
through
the
E
G
R
passage
The
exhaust
gas
is
then
con
trolled
in
quantity
by
the
E
G
R
valve
and
is
introduced
into
the
intake
manifold
In
the
exhaust
gas
recirculation
system
a
part
of
the
exhaust
gas
is
returned
to
the
combustion
chamber
U
S
A
models
c
r
i
From
carburetor
EC309A
1
E
G
R
thermal
vacuum
valve
2
E
G
R
control
valve
3
Carburetor
4
E
G
R
passage
5
Intake
manifold
6
Exhaust
manifold
7
E
G
R
tube
8
Orifice
9
B
P
T
tube
10
B
P
T
valve
Canada
models
CD
o
1
Thermal
vacuum
valve
2
E
C
R
control
valve
3
Carburetor
4
E
C
R
passage
5
Intake
manifold
6
Exhaust
manifold
7
E
G
R
tube
Thermal
vacuum
valve
3
port
type
T
V
V
Thermal
vacuum
valve
2
port
type
T
V
V
for
FU
model
E
G
R
tube
E
G
R
control
valve
4
Thermal
vacuum
valve
2
port
type
T
V
v
E
G
R
tube
EC155A
Fig
EC
63
E
G
R
System
EC
21