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i am going to reinstall the factory bpv on my car.the only problem i have is that one of the nipples on the vtv (the little round doo dad w/vacum line attached) broke.can i get this item at a local auto part store or will i have to order it from toyota?if i have to order it from toyota what will i ask for.can i glue the nipple back on w/super glue or will that not be good enough?
 

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91 Turbo MR2
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Good reading here:
http://www.jekylhyderacing.com/bov.htm

Originally posted by billwot
Here is an old writeup I used to post. Reference to "check valve" measn the VTV (It isn't a true check valve).

"The large round area at the top is a diaphragm. The area on the top of the diaphragm is larger than the area under the diaphragm. Now note there is hose directly from the manifold to the top (large area) of the diaphragm, and another hose tee's off that goes through a check valve to the underside (small area) of the diaphragm. When there is pressure (boost) in the manifold, there is equal pressure on both sides of the diaphragm, but since force=pressureXarea, the greater force on the top holds the valve closed. In fact, the higher the boost, the more tightly the valve is held closed.

Now as soon as you lift, and pressure starts to drop in the manifold, air immediately escapes from the top of the diaphragm, but the check valve restricts it from escaping on the bottom, and the pressure on the bottom quickly exceeds the pressure on the top, and the valve snaps open. If you reverse or eliminate the check valve (VTV) then you can't trap pressure under the diaphragm, and the valve cannot respond as quickly.

Conversely, the check valve insures that when there is a vacuum condition, more vacuum will be applied to the top of the diaphragm, and it will open and be in bypass mode.


The diaphragm section of the valve is connected to a spool in the main section of the valve. That spool opens and closes the connection between the crossover pipe and the intake air pipe. When the diaphragm is pushed (or pulled) to the top, the valve is open, and when it is pushed to the bottom, it is held closed.

There is just a light spring on the spool in the main body. Its only function is to return the valve to its normally closed condition when the engine is not running."
 
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