I have a 1g bov and I think its bad.. When i blow on the vacuum port, it flows through the small port on the bottom side of the BOV.. I guess the rubber like diaphragm is gone/rotted/has a hole in it?

or should it do this?

 

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I'm 99% sure that behavior is part of its design. Your talking about the small pinhole right next to the valve on the bottom right?

 

I'm 100% sure it shouldn't. If you blow into the vacuum port (the nipple that the signal hose attaches to), it shouldn't go anywhere. As another test- push the valve piston up all the way, and then put a finger over the nipple and let go of the piston. Wait a second and take your finger off the nipple. There should be some vacuum sucking your finger against the nipple. I'll bet there isn't, though, in your case, and if there isn't, you have a junk BOV.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Loco Honkey &raquo;</TD></TR><TR><TD CLASS="quote">I'm 100% sure it shouldn't. If you blow into the vacuum port (the nipple that the signal hose attaches to), it shouldn't go anywhere. As another test- push the valve piston up all the way, and then put a finger over the nipple and let go of the piston. Wait a second and take your finger off the nipple. There should be some vacuum sucking your finger against the nipple. I'll bet there isn't, though, in your case, and if there isn't, you have a junk BOV.</TD></TR></TABLE>

The behavior is by design. Its not a great design, but it doesn't mean its broken either. Scroll to the bottom of this page and order this $10 kit if you want to change the way it works:

http://www.dejontool.com/dsm-misc.htm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ITR981002 &raquo;</TD></TR><TR><TD CLASS="quote">The behavior is by design. Its not a great design, but it doesn't mean its broken either. Scroll to the bottom of this page and order this $10 kit if you want to change the way it works:

http://www.dejontool.com/dsm-misc.htm</TD></TR></TABLE>

I'm sorry, but I disagree. I have a 1G BOV in my AllTrac, and had one in my Civic, and am quite versed in how the valve is supposed to work. That port you see on the bottom of the valve in those pics is to pressurize the chamber on the bottom of the diaphragm, which aides in opening the valve during shifts. The nipple on the top of the actuator housing is for vacuum and pressure in the chamber on top of the diaphragm. The chambers on top of and below the diaphragm should not connect in any way. Doing so would negate the usefulness of the valve, as pressure won't be allowed to build in the upper chamber. If there's no pressure in the upper chamber to keep the valve seated, it will open at approximately 3 PSI. I know this because I drove my car without the signal line hooked up, and at about 3 PSI, I heard a loud hissing noise and a noticed a drop in performance (goddamn MAF sensors).

To address what they have on that page- it is a valve that's designed to prevent boost from entering the chamber below the diaphragm, which will work against the pressure in the top chamber and will try to open the valve. This only becomes an issue at around 15 PSI.

Hope that helps.