Airbox Check Valves

[paul102a3]

I understand the reason for the airbox check valve but I am confused as to how it functions. Is the valve open to drain "stuff" at idle and then closes as pressure builds up in the airbox? Is the checkvalve spring loaded or is it supposed to rattle if shaken back and forth.

I have one of the valves off the engine right now and the valve doesn't seem to seal if I inject air into it so I am wondering if it is not working correctly.

The valves are on a 8V92.

Any help would be appreciated.

Paul

[RickB]

Paul,

Dallas is probably the best source on this but I believe you hit the nail on the head. From my understanding the valve should stay open until around 7-800 RPM's and should close at that point because the engine is operating at a more efficient RPM and is burning more/all of the fuel.

Dallas had me clean mine with parts cleaner, check the spring for rension and make sure with (if I remember correctly) from very low pressure to around 25-30 lbs of compressed air to make sure that it was sealing correctly at low pressure and opening correctly at higher pressure.

Mine almost completely quit slobbering at idle and are really sealing well at speed as well.

Hope it helps,

Rick

[RickB]

Paul

My bad...

"was sealing correctly at low pressure and opening correctly at higher pressure."


Sorry, reverse those. It should have read:

Opening correctly at low no/low pressure and closing correctly at higher pressures.



Rick

[luvrbus]

Paul, those valves from a 8v92 will not work on a 90 or 180 degree angle make sure you are testing at a 40 to 45 degree angle down and they do rattle when shaking if they are clean Good luck