Variable Induction Control Valve: Testing and Inspection
IAB Valve Testing1. Check the IAB valve shaft for binding or sticking.
2. Check the IAB valve for smooth movement.
3. With the engine OFF, check that (A) of the bypass valve is in close contact with the stop.
4. With the engine at idle, check that (B) of the IAB valve is in close contact with the full-close screw.
If any fault is found, clean the linkage and shafts with carburetor cleaner.
If the problem still exists after cleaning, disassemble the intake manifold and check the IAB valve.