Subaru 1600 Service Manual page 189

3) Check valve II
I) Confirm that there is no air flow
from the carburetor side to the dis-
tribu tor side.
2) Confirm that there is air flow
from the distributor side to the carbu-
retor side.
.11===
To distributor
1 Valve
2 Spring
Fig.
544
Check valve
A10-108
3) Ignition Control System
1) Thermo vacuwnvalve (I):
Refer to "EGR system".
2) Check valve (II):
Refer to "AI system".
4) Anti-afterburning System
1) Air passage hose
Check hose and its connection for
leakage and looseness. If leakage is
found, replace it with new one.
2) Vacuwn line
Check vacuum line for leakage and
looseness as foJlows.
1) Disconnect the vacuum hose from
AA V, then run the engine.
2) Confirm that air is sucked into the
vacuum hose.
3) If not, vacuum line is defective.
3) AAV
Holding a paper under the AA V, run
engine up to 3,000 rpm then close the
throttle valve quickly.
If the paper is
sucked at this moment, the AAV
operates normally. If not, the AAV is
defective. Replace it with new one.
EMISSION CONTROL SYSTEM
1 Intake manifold
2
Air passage
I
CD
3 Anti·afterburning valve
4 Vacuum line
5 Ball
®@@
\
A10-198
Fig.
545
Anti-afterburning system
5. Troubleshootinc for
ECC System
1) Outline
The air-fuel ratio in the carburetor is
compensated by turning ON or OFF
the compensation air circuit of the
duty solenoid valve at an appropriate
3) Relations between self-diagnosis,
ECS lamp, and O
2
monitor lamp
[~
Diagnosis
in
progress
ECS lamp
OFF
duty ratio according to the operating
condition.
Note that the duty changes from time
to time, being controlled by various
sensors. Accordingly, if the duty for
the duty solenoid valve is improper,
some malfunction occurs in the car.
Described below are the main points
of troubleshooting the ECC system.
I) Self-diagnosing function
This system has a self·diagnosing func·
tion. When trouble occurs, the ECS
(Electric Control System) lamp is
illuminated and the trouble code is
displayed on the O
2
monitor lamp in
Morse Code.
2) Changeover from regular mode to
test mode
The self.diagnosing function is availa-
ble in two modes: Regular Mode and
*Test Mode.
It
is automatically
changed over to the test mode by
connecting the test mode connector.
(The test mode connector must always
be disconnected after tests.)
*
Test mode is a special mode pro·
vided for the dealer to perform self-
diagnosiS quickly.
Diagnosis result on display
Regular mode
Test mode
OK
NG OK NG
OFF ON Flickers ON
O
2
monitor lamp
O
2
O
2
Trouble O
2
Trouble
monitor monitor code
monitor code