Did a low psi boost leak test.... now i have some questions

[silviasgp06]

So I finally got time between classes, work and life to do a boost leak test.

Method: Pressurized the system (<10psi) by using a PVC plumbing cap with a valve stem in the stock turbo intake tube.(basically replaced the MAF with the cap). Then sprayed soapy water all over the system.

Findings:The system seemed to have no leaks. BUT bubbles came from the FPR and Mechanical Boost controller.

Questions: I think its normal for the boost controller to bleed off air but is the FPR supposed to do this?

the photo below (showing bubble locations )is the style of FPR I have but mine is a project nissan FPR not a Sard


Modified by silviasgp06 at 7:57 AM 4/8/2010

[Darius]

<edit> double post...
Modified by Darius at 10:13 AM 4/8/2010

[Darius]

I'd slather those threads with loc-tite blue. If it is leaking boost pressure at the FPR, that will have an immediate impact on the fuel pressure for a given boost pressure.

[gawdzilla]

you're right about the MBC. they have a bleeder hole and should leak out of that hole.

the FPR shouldn't though. sounds like you need to disassemble it and use some thread sealant or teflon tape on it. you don't want a leak there because that will affect your fuel pressure under boost.

[Carl H]

liquid pipe sealant on the fpr threads...not loctite.

[silviasgp06]

thanks guys!

I thought about putting RTV on the threads but never seen "liquid pipe sealer" on the shelves before at an auto parts store. Maybe I just never noted it or are you talking about the stuff you can get at home depot?

[Carl H]

you can get it at any reasonably stocked parts store, its sold in the rtv section

[silviasgp06]

awesome

[gawdzilla]

rtv would probably work too

[robbie2883]

it's liquid thread paste / sealer. it's white and comes in a little jar lootking thing with a bush built into the cap. it's basically liquid teflon tape. you can buy it anywhere that sells plumbing supplies and in some auto stores.

honestly though...if it was me...i'd just use teflon tape. it's alot less messy, cheap, easy, removable and seals just as good

[Darius]

For the air fittings, teflon tape or paste should work fine.

Do not use teflon tape or paste on the actual gasoline line fittings though. It reacts with gas and turns to goop. If you get it inside the fuel rail at all, that goop gets into injectors. Clogged injectors=lack of fuel=engine go boom. Use LOC-TITE on those!