Subaru 1600 Service Manual page 70

3) With the hot air inlet in open
position. as described in 2). pinch the
vacuum hose with fingers so that the
air does not enter the vacuum motor.
In this condition. check that the air
control valve maintains the condition
described in 2) for more than 30
seconds. and that the hot air inlet is
open. If the diaphragm spring actuates
the air control valve by its spring force
to open the under hood air inlet
within 30 seconds. replace the vacuum
motor as an assembly since this may
have resulted from air leak at the
vacuum motor diaphragm.
ENGINE
3) Temperature Sensor
Check temperature sensor for prop-
er function by proceeding as follows.
Be sure to keep the engine cold before
starting this test.
1)
With the engine stopped. check
the position of the air control valve. In
this case, underhood air inlet should
be open. Use a mirror for inspection as
2) - I).
2) Start the engine and keep it
idling. Immediately after engine start-
ing, check the air control valve for
correct position as described above. In
this case, the correct position of the
air control valve is the reverse of
2)-1); the under hood air inlet is
closed. and the hot air inlet is open.
Operation of air control valve and sensor valve
3) Check that the air control valve
gradually moves to open the under
hood air inlet as the engine warms up.
When the environmental temperature
around the temperature sensor is low.
spend more time for engine warming
up operation to facilitate smooth oper-
ation of the air control valve.
4) Rubber Plate
Check the rubber plate for sticki-
ness.
5} Air Intake Hose
Check the air intake hose for dam-
age and its connections for leaks.
Under hood air
Vacuum on vacuum motor diaphragm
Air control valve operation
Sensor valve
temperature operation
Below
S.3
kPa (40 mmHg. 1.57 inHg)
Below 38°C (100°F)
Above 16.0 kPa(120 mmHg, 4.72 inHg)
38 - S3°C (100 - 127°F)
Above S3°C (l27°F)
. S. En.lne Idle Speed and Idle Mixture
1) Engine Idle Speed
Refer to 2·2. 8. Engine Idle Speed in
Chapter 2.
2) Engine Idle Mixture
NOTE:
Perform the idle mixture adiultment
only when dismounting carburetor
from angina or ditalsambling carb.
retor. And after completion of adjust-
ment, ba lUre to pr_ spring pin into
the hole in throttle chambar.
Cool air admission
Close
Hot air admission
Cool and hot air mixture
Open
admission
Cool air admission Open