Inspection Of As System; Inspection Of Reed Valve; Inspection Of Vacuum Control Valve - Volkswagen Taro 1989 Workshop Manual

INSPECTION OF AS SYSTEM
l .
Visually check hoses and tubes tor cracks, kinks, damage or
loose connections
2. Disconnect air suction hose from AS reed vavle
3.
Check reed valve
(a) Start the englne and check that a bubbling nolse
IS
heard
fromthe reed valve at idle
(b) Disconnect the vacuum hose from the AS reed valve
(C) Check that a bubbling noise
IS
not heard
(d) Reconnect the vacuum hose
4. Check vacuum control valve (VCV)
Race the englne and quickly close the thronle valve
Check that there 1 s not bubbllng nolse from the AS reed valve
tmmedlately after releasmg the pedal
IF NO PROBLEM IS FOUND WITH THIS INSPECTION. THE
SYSTEM IS OKAY OTHERWISE INSPECT EACH PART
INSPECTION OF REED VALVE
Check reed valve by blowing air into pipe
(a) Apply vacuum (2) to the reed valve diaphragm
(b) Blow air (1) Into a plpe and check that the reed valve 1s
open (3)
(C) Release the vacuum
(4)
and check that the reed valve 1 s
closed (5)
INSPECTION OF VACUUM CONTROL VALVE (VCV)
Check VCV operation
(a) Dlsconnect the vacuum hose from pon
Z
of the VCV
(b) Connect port Z directly to the intake manifold with
another hose, and disconnect the vacuum hoses from parts
S and X of the VCV
(C) WRh the engine Idllng, place your finger over pon
X
and
check that vacuum 1 s not felt
(d) Check that vacuum is felt momentarily as the vacuum hose
IS
reconnected to pon S