Subaru 1600 Service Manual page 186

a. EGR valve cleaning
CAUTION:
Do not wash valve ASSY in solvents or
degreaser as permanent damage to
valve diaphragm may result.
(l) Hold the valve ASSY in hand,
then tap lightly on the sides and
end of the valve with a small plastic
hammer to remove the exhaust
deposits from the valve seat. Empty
loose particles. DO NOT PUT IN A
VISE.
(2) With a wire wheel or deposit
cleaning tool, buff the exhaust
deposits from the mounting surface
and around the valve.
(3) Depress the valve diaphragm and
look at the valve seating area
through the valve outlet for clean-
liness. If valve and/or seat are not
completely clean, repeat Step (1).
(4) Look for exhaust deposits in the
valve outlet. Remove built-up de-
posite with a screwdriver.
(5) Blowout small particles and dust
remaining with air hose.
(6) Check EGR valve operation by
applying -26.7 kPa (-200 mmHg,
-7.87 inHg) vacuum with hand
vacuum pump. If valve does not
open completely, replace EGR
valve with a new part.
NOTE:
When reassembling EGR valve, replace
EGR valve gasket with a new
ORB.
b. Exhaust gas passage cleaning
(1) Inspect EGR gas inlet to intake
manifold for presence of deposits.
Remove any deposits present with a
hooked awl taking care to minimize
the amount of material falling into
the intake manifold.
DO NOT USE AN ELECTRIC
DRILL.
(2) Remove all deposit material using
a vacuuming device.
(3) Examine EGR Gas Inlet for ex·
haust deposits.
If
excess deposits
EMISSION CONTROL SYSTEM
present, (more than 5 to 10%
blockage of the passage), remove
EGR pipe. Tap lightly on the sides
of the EGR pipe with a small
plastic hammer to loosen exhaust
deposits. Remove loose exhaust
deposits by blowing through EGR
pipe using compressed air. Reas-
semble EGR pipe.
(4) Inspect and clean EGR valve as
required (See a. EGR valve clean-
ing).
2) Thenno vacuwn valve (I)
1) Connect vinyl tubes to output
ports to air cleaner and EGR valve,
and plug the output port to distributor
with a cap. Blow air into the valve as
shown in the illustration, and confirm
that the valve opens or closes in
response to intake manifold wall
temperature as specified.
@
(j)----\lt+_
1 Wax
2 Valve
3 Spring
4 Valve seat
• To air
cleaner
, - - - - - 1 •
To E.G.A.
valva
.To
Jrr=::::i
distributor
A10-105
Fig.5-35 Thermo vacuum valve
(I)
Vinyl tube
Cap
<,J()~- Thermo vacuum
valve HI
A10·106
Fig. 5-36
Thermo vacuum valve (I) should be
open below 30°C (86°F) completely
and close above 40°C (l04°F) com-
pletely. If out of specification, replace
it
with a new one.
NOTE:
Do not allow water to get into thermo
vacuum valve
(I).
2) Connect vinyl tubes to output
ports to EGR valve and distributor,
and plug the output port to air cleaner
with a cap. Blow air into the valve as
shown in the illustration, and confirm
that the valve opens or closes in
response to intake manifold wall
temperature as specified,
Vinyl tube
Cap
--Hl--:lIIrI /I
~r-t- Thermo vacuum
=:;~r;:;;;;:e:=
valve
m
A10·107
Fig. 5-37
Thermo vacuum valve (I) should be
open above 20°C (68°F) completely
and close below 10°C (50°F) com-
pletely.