losing boost

[riceviper]

i have a mbc and when i hooked it up i teaed into the bov line and i have it set at 15psi and it will get there but when it does it just goes right back down to 11 psi and am not letting off the gas.

 

[riceviper]

would teaing into the bov cause this?

 

[logan0093]

I have the same problem.

 

[reeper]

Have you performed a boost leak test?

http://www.vfaq.com/mods/ICtester.html

 

[skinnykenny84]

If this problem started imediately following the boost controller install then there lies the problem. But yes always do boost leaks, I get a new one every month
As far as if you installed it correctly, yes you do tie in to the bov line and tie into the vaccum line going to the turbo, but you have to know what to eliminate and what not to. Did you follow this http://www.belitski.com/vfaqhallman.html ?

 

[logan0093]

I have no boost leaks. I do have a slight idle problem. Isc is in good working order, but in order to get the rpms down my biss is turned almost all the way in.

 

[u12run]

Correct me if I am wrong but isn't this normal. My boost tapers all the time. It hits 20 lbs then go downs to 17-18

 

[blcknspo0ln]

This is not a common problem with 14b turbos. With the t25, it is. Anyway, It definitely sounds like either like a: boost leak, boost control, or WGA problem. I suppose just use the process of elimination to find your solution. Start by going back and doing a boost leak test with soapy water, then swap MBC's with a known working one, then pressure/air test your WGA to make sure it is opening and closing correctly. It could possibly be that it is old and tired enough to not hold your flapper door closed during WOT conditions.

 

[SoonToBeDSM06]

It could be a boost leak but maybe you have the MBC set for 11 psi. It might spike to 15 psi and drop. I had that happen but mine spiked to 20 psi on the stock injectors so it was a little scary. It could spike if your vacuum line for it is too long.