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Another way to find Vaccum Leaks???

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Old 11-29-07, 08:17 PM
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Another way to find Vaccum Leaks???

Anyone know how else to find a vaccum leak? I tried having having the car idle and spraying Carb+Choke cleaner on it and nothing. I know I have a vaccum leak for sure. Use to idle at -20vac and now at -10vac, and besides that, the BOV doesnt work. I know the BOV has vaccum to it and I just bought a new BOV and still doesnt work. My guess is a vaccum leak. Anyone know an EASY way to nail a vaccum leak. I can even hear it, just cant find the stupid thing.
Old 11-29-07, 08:20 PM
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Sometimes you can pressurize the intake and spray soapy water around.

I don't think this is necessary if you can hear the vacuum leak, I would just move around the car until it is the loudest and then simply move each vacuum line in turn to see if the sound changes, when it does, you found the leaking hose.
Old 11-29-07, 10:07 PM
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try this.

take an unlit propane torch, crack the valve open and use it to probe around the engine where you think the leak is, you'll hear the engine pick up rpm when your on top of it. it's pretty precise and doen't get your engine covered in flammable liquids or water. It helped me.
Old 11-29-07, 10:30 PM
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I heard seafoam works
Old 11-30-07, 12:02 AM
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Would a vaccum hose somewhere else besides the one on the BOV, cause the BOV not to work? I ordered a new BOV and still not working... Any ideas?
Old 11-30-07, 12:46 AM
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whats not working about it?
Old 11-30-07, 06:12 AM
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maybe hooked up to worn vac port? is the guage and bov t'ed of togther?
Old 11-30-07, 07:52 AM
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Yes they are both t-ed together. Is that a problem? And both run to a vac nipple of the UIM. Is that not good? I know I have vaccum though to the BOV. I can pull the hose off the bov and it would stick to my finger.
Old 11-30-07, 09:37 AM
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Anyone?
Old 11-30-07, 01:39 PM
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Originally Posted by agallardo
Yes they are both t-ed together. Is that a problem? And both run to a vac nipple of the UIM. Is that not good? I know I have vaccum though to the BOV. I can pull the hose off the bov and it would stick to my finger.
no, that's what you want..... again, what is not working about the BOV, it's not opening?
Old 11-30-07, 08:14 PM
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smoke machine. some auto repairs shops have them.
Old 11-30-07, 09:56 PM
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If you have a compressor, read this:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/water-sensors-water-pump-diff-models-583211/ (Scroll down to posts #11 and #16)
Old 11-30-07, 09:57 PM
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Originally Posted by texFCturboII
no, that's what you want..... again, what is not working about the BOV, it's not opening?
Yeah my bov is not opening. Opens up barely in high boost though. What else can cause this problem.

Well today I noticed something that might be the problem. Before I installed my FMIC there is the stock hose that runs to a nipple right next to the stock bov/setup, that short and pretty big hose. Anyway, when I putting the fmic, that hose had like an inline 'fuel filter-type' look alike. But this one is solid grey and has an arrow pointing in one direction. Is this neccesary to keep in that line? I just eliminated it and but a hose from the UIM/ vaccum source (stock) to a nipple I tapped into the intercooler piping connected to the turbo. Is it neccesary to have?
Old 11-30-07, 10:11 PM
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1st 2 pics are of that piece that I found inline with the hose that connected stock behind the stock bov setup.

2nd 2 pics, wandering if anyone sees anything wrong?
Attached Thumbnails Another way to find Vaccum Leaks???-unknown.jpg   Another way to find Vaccum Leaks???-unknown2.jpg   Another way to find Vaccum Leaks???-wrong.jpg   Another way to find Vaccum Leaks???-wrong2.jpg  
Old 11-30-07, 10:47 PM
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you are referring to a one-way check valve....

a vac leak will usually bring vac up and raise idle.....

there is no way to miss a vac leak with the car running and using ether......
Old 11-30-07, 10:58 PM
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Originally Posted by NZConvertible
If you have a compressor, read this:

https://www.rx7club.com/showthread.php?t=583211 (Scroll down to posts #11 and #16)
Propane, smoke, seafoam? WTF....^^^ the only good idea here so far
Old 12-01-07, 12:25 PM
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Originally Posted by zbrown
you are referring to a one-way check valve....

a vac leak will usually bring vac up and raise idle.....

there is no way to miss a vac leak with the car running and using ether......
So do I need that one-way check valve in? Does that have anything to do with the bov not working?
Old 12-01-07, 07:15 PM
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ANYONE??? No one has an idea?
Old 12-01-07, 07:29 PM
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http://www.boostpro.net/prodtester.html

If you do not want to fabricate your own, this website sells pressure testers. You just need to buy a coupler. They also have one with a tire valve connector on it. So you will not have to buy an expensive impact-tool grade compressor to make this work.
Old 12-01-07, 07:30 PM
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Originally Posted by agallardo
So do I need that one-way check valve in?
That check valve is part of the PCV system. It has nothing at all to do with the BOV.

Does that have anything to do with the bov not working?
Nothing at all.
Old 12-01-07, 07:45 PM
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Originally Posted by arghx
http://www.boostpro.net/prodtester.html

If you do not want to fabricate your own, this website sells pressure testers. You just need to buy a coupler. They also have one with a tire valve connector on it. So you will not have to buy an expensive impact-tool grade compressor to make this work.
But that would just check the intercooler cooler system/turbo setup vaccum only, right? not any other vaccum hoses?
Old 12-01-07, 07:54 PM
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http://www.boostpro.net/prodtester.html

interesting!
i might buy this.
Old 12-01-07, 07:55 PM
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It pressures your entire engine. Think about it, the air goes through the intercooler pipes into the intake manifold, which is connected to all your vacuum hoses etc. Read that link that NZconvertible posted up.

I have it, although I haven't used it yet because I need a reducer to make it work with my turbo. I've helped my friend use a similar one on his VR-4, and you would be amazed how many little bullshit leaks can develop.
Old 12-01-07, 08:05 PM
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Originally Posted by arghx
It pressures your entire engine. Think about it, the air goes through the intercooler pipes into the intake manifold, which is connected to all your vacuum hoses etc. Read that link that NZconvertible posted up.

I have it, although I haven't used it yet because I need a reducer to make it work with my turbo. I've helped my friend use a similar one on his VR-4, and you would be amazed how many little bullshit leaks can develop.
Did you guys make your own? I it seems pretty easy to make.... HOME DEPOT stuff...
Old 12-01-07, 08:08 PM
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Dude. Read NZconvertible's post.


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