Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Component Test

CAUTION: Do not adjust Intake Air Bypass (IAB) valve full-close screw. It is factory preset.

1. Check IAB valve shaft for binding or sticking.
2. Check valve for smooth movement.

Intake Air Bypass Stopper:





3. With engine OFF, be sure "A" of the IAB valve is in close contact with stopper.

Intake Air Bypass Full Close Screw:





4. With engine idling, be sure "B" of the IAB valve is in close contact with the full-close screw.
^ If problem found, clean linkage and shafts with carburetor spray cleaner.

Intake Air Bypass Control System:





^ If problem still exists after cleaning, disassemble the intake manifold and check the IAB valve body assembly.