Intake Air By-Pass (IAB) Control Valve Inspection
- Check valve shaft for binding and sticking, and ensure movement is smooth. Turn engine off. Ensure tab on IAB control valve contacts stop. See Fig 1.
- Start engine and allow to idle. Ensure tab of IAB control valve contacts full-close screw. If any fault is found, clean linkage and shafts using carburetor cleaner. If problem still exists after cleaning, disassemble intake manifold and inspect IAB valve assembly.
Courtesy of AMERICAN HONDA MOTOR CO., INC.