Intake Air Bypass (IAB) Control Valve Testing
CAUTION: Do not adjust the IAB control valve full-
close screw. It was preset at the factory.
1. Check the IAB control valve shaft for binding or
sticking.
2. Check the IAB control valve for smooth movement.
3. Check that of the IAB control valve is in close
contact with the stopper when the vacuum hose is
disconnected from the IAB control diaphragm.
STOPPER
4. Check that of the IAB control valve is in close
contact with the full-close screw when you apply
380 mm Hg (1 5 in. Hg) of vacuum to the IAB con-
trol diaphragm.
If any fault is found, clean the linkage and shafts
with carburetor cleaner.
FULL-CLOSE
SCREW
If the problem still exists after cleaning,
disassemble the intake manifold and check the
IAB valve body assembly (see page 11-140).
(cont’d)
CAUTION: Do not adjust the IAB control valve full-
close screw. It was preset at the factory.
1. Check the IAB control valve shaft for binding or
sticking.
2. Check the IAB control valve for smooth movement.
3. Check that of the IAB control valve is in close
contact with the stopper when the vacuum hose is
disconnected from the IAB control diaphragm.
STOPPER
4. Check that of the IAB control valve is in close
contact with the full-close screw when you apply
380 mm Hg (1 5 in. Hg) of vacuum to the IAB con-
trol diaphragm.
If any fault is found, clean the linkage and shafts
with carburetor cleaner.
FULL-CLOSE
SCREW
If the problem still exists after cleaning,
disassemble the intake manifold and check the
IAB valve body assembly (see page 11-140).
(cont’d)