Air Intake Controls

1. Remove air cleaner cover and filter element, then disconnect air intake and hot air ducts, if necessary.
2. With engine cold, crank engine for approximately 5 seconds. If air control door rises and remains fully open for at least 3 seconds, reinstall filter element and air cleaner cover and proceed to step 8. If door does not rise, check to see if door is binding. If door still does not rise, or fails to remain open for 3 seconds after cold cranking test, proceed to step 3.
3. Disconnect and plug hose leading to air bleed valve.
4. Crank engine for approximately 5 seconds. If door rises and stays up for at least 3 seconds, replace air bleed valve and repeat steps 2-4.
5. If door does not rise or stay open for at least 3 seconds, disconnect vacuum hose from air control diaphragm. Remove deflector plate, if equipped.
6. Raise air control door manually and, while blocking inlet pipe, release door. If door stays up, replace check valve and recheck. If not, replace air control diaphragm and recheck.
7. Reinstall filter element and air cleaner cover.
8. With engine running and cooling fan on, disconnect air intake duct on 1983-86 Prelude or remove air cleaner cover and filter element on all other models and immediately check control door position. If control door has fully closed hot air intake duct, stop engine and reinstall filter element and air cleaner cover.
9. If control door has not closed fully, disconnect vacuum hose to air control diaphragm. If control door now closes, replace air bleed valve and recheck. If not, correct whatever is causing door to bind, and/or replace air control diaphragm and recheck.
10. Stop engine and reinstall filter element and air cleaner cover or air intake and hot air ducts.