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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
ofcrack
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
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