Subaru 1600 Service Manual page 69

4. Hot Air Control
System
Inspect the hot air control system
periodically as follows.
In warm weather, it is difficult to
find out malfunction of the hot air
control system. In cold weather, how-
ever, malfunction of the air control
valve due to disconnection or deterio-
ration of the vacuum hose between the
intake manifold and vacuum motor
and insufficient durability of the air
1 Vacuum motor
2 Temperature sensor
3 Throttle valve
4 Intake manifold
S
Vacuum hose
6 Air stove
7 Air intake bose
8 Air control valve
9 Air hom (Snorkel tube)
1 Vacuum motor
2 Temperature sensor
FIg.
3-32
Hot ,ir control systBm
ENGINE
control valve will cause insufficient
automatic control operation for intake
air, and result in engine disorders:
I) Stall or hesitation of engine oper-
ation,
2) Increase in fuel consumption, and
3) Lack of power.
These phenomena reveal malfunc-
tion of hot air control system. If these
phenomena should occur, check the
hot air control system for the follow-
ing items before carrying out inspec-
tion of the carburetor.
A5·383
3-32
1) Vacuum Hoses
Check each hose for cracks and
proper connections.
2)
Vacuum Motor
1) With the engine stopped, place a
mirror at the end of the air cleaner
inlet pipe as shown in the figure, and
check to see if the air control valve is
Mirror
Vacuum motor
Air intake hose
A5·385
Fig.3-33 InlP6Cting vsl", position
The air control valve is in correct
position if its under hood air inlet is
open and hot air inlet is closed. Check
the condition of the air control valve
linkage.
2) Disconnect the vacuum motor
inlet vacuum hose, and connect an-
other hose to the inlet to apply vacu-
um to the vacuum motor. Vacuum can
be applied by sucking at the hose end
as shown in the figure.
Place a mirror at the end of the air
cleaner inlet pipe, and check to see
if
the air control valve is in correct
position.
2 Vacuum motor
A 5·386
FIg.3-34 InlP6Cting vsl", position
Correct position of the air control
valve is the reverse of that described in
I) above. The air control valve is in
correct position if the under hood air
inlet is closed, and the hot air inlet is
open.