Subaru 1600 Service Manual page 170

b. To pull apart electrical connectors,
pull on the connector itself, not the
wire.
c. Be careful not to drop electrical
parts, such as sensors, or relays.
If they are dropped on a hard floor,
they should be replaced and not
reused.
d. When steam cleaning an engine,
EMISSION CONTROL SYSTEM
protect the distributor, coil, air
cleaner, carburetor from water.
e. When checking continuity at the
wire connector, the test bar should
be inserted carefully to prevent
terminals from bending.
6) Use SUBARU genuine parts.
7) Record how hoses are connected
before disconnecting.
a. When disconnecting vacuum hoses,
use tags to identify how they
should be reconnected.
b. After completing a job, double
check to see that the vacuum hoses
are properly connected. See the
"Vacuum connections label" under
the hood.
5·2. Crankcase Emission Control System
1. Description
The positive crankcase ventilation
(PCV) system is employed to prevent
air pollution which will be caused by
blow-by gas being emitted from the
crankcase.
The system consists of a sealed oil
filler cap, rocker covers with an emis-
sion outlet and fresh air inlet, con-
necting hoses, PCV valve and an air
cleaner.
At the part throttle, the blow-by gas
in the crankcase flows into the intake
manifold through the connecting hose
of rocker cover on
#2-#4
side and
PCV valve by the strong vacuum of the
intake manifold. Under this condition,
the fresh air is introduced into the
crankcase through connecting hose of
rocker cover on
# 1-#3
side, and
drawn to the intake manifold through
PCV valve together with the blow-by
gas.
At the wide open throttle, a part of
blow-by gas flows into the air cleaner
through the connecting hose of rocker
cover on
# 1-#3
side and is drawn to
the carburetor, because under this
condition, the intake manifold vacuum
is not so strong as to introduce all
blow-by gases increasing with engine
speed directly through the PCV valve.
Under the special operating condition,
such as steep right turn driving, engine
oil sometimes blows up into connect-
ing hose of rocker cover on
#2-#4
side and flows into the intake manifold
by the force of the vacuum.
However, in this case, the connecting
hose between air cleaner case and
connecting hose of rocker cover on
#2-#4
side reduces the vacuum to
prevent this.
@ @
@
Fig.
5-1
1 Connecting hose
2
P.C.V. valve
3 Carburetor
4
Air
cleaner
5 Air filter
6 Connecting hose
2. Inspection
I) Check the positive crankcase
ventilation hoses and connections for
leaks and clogging. The hoses may be
cleared with compressed air.
2) Check the oil filler cap to insure
that the gasket is not damaged and the
cap fits firmly on the filler cap end.
3) Check the PCV valve as the
following procedure.
a. Disconnect the hose from the PCV
valve.
b. With a finger attaching top of the
valve, then lightly open and close
the throttle valve (increase and
decrease the engine speed a little).
c. The valve is in good condition if a
vacuum is felt by the finger. If not,
replace the valve.
d. The valve alone may be checked by
-@
®
.... Fresh air
.... Blow-by gas
- Mixture of air and
blow-by gas
7 Oil filler cap (Sealed)
8 Connecting hose
9 Rocker cover on #2 -
#4
side
10
Crankcase
11 Rocker cover on #1 - #3 side
A10.060
shaking it. It is normal when you
hear it move. Replace it if it fails to
move.
To intake manifold
Fig.
5-2
1 Case
2 Valve
3 Spring
A10-oS6