Im having a problem with mine. it used to work retty well and i was able to adjust boost up or down no problem. Then it sarted acting like there was vaccum to the wategate and i was hitting 20+psi (thats all my gauge reads to) that cause a cracked piston on my b20. So i took the hose off and ran it straight off the turbo to the wastegate and it goes to 7.5psi. So i took apart my TurboXS MBC and was expecting a spring and ball and **** but theres nothing in there. SO isnt there supposed to be all that stuff in the boost controller or is TurboXS different?

 

which turboxs controller you have the xs highperofarmance manual is spring and ball design the basic model is just valve.

 

well im having problems with it. when i run a line straight from the turbo to the side port on the wastgate, it hits 7-7.5psi no prob. Now when i put the boost controller in, it goes straight up to 15+ (thats when i let off). i have the line coming from the outlet of the turbo to the side of the MBC (brass fitting) and the bottom port goes to the wastegate. Can these things go bad over time, i know this has been on several cars in the past.

 

have you adjusted the allen nut usually they dont go bad but tighten it all the way down and reset it by turning it coutner clockwise 3 times and then for every turn it should be 1psi increments or so

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bturbo &raquo;</TD></TR><TR><TD CLASS="quote">have you adjusted the allen nut usually they dont go bad but tighten it all the way down and reset it by turning it coutner clockwise 3 times and then for every turn it should be 1psi increments or so</TD></TR></TABLE>

Ya i did that. this thing used to work. Not exactly 1lb for 1 turn, but close. This is gay, i wanna be around 12psi. But right now its 20+ or 7 lol

 

just scrap it and get another one they are easily found and cheap. even the knockoff ones.

 

would too big of lines be causing the problem? ive got some pretty big hoses on there, not outrageous, but bigger than normal vaccum lines/

 

you should tighetn it all the way down if it gives you 7psi then it works still then back it up one complete turn and see what happens.

 

My dad had this problem after a few years with that controller. He took that whole assembly apart and blew air through everything and put it back together and it worked. No idea what happened on the inside to make it do this, but that is what he did to fix it.

 

ya i took it all apart and cleaned it with brake cleaner and blew it off with air. And all the way tightened down should mean it runs off the spring, or even 3 turns out. But no matter what i do it shoots straight to 15+ (15 is where i let it go to and then i let off). like i said, i can blow through it even with air when its off the car pretty freely. i dont understand why it wouldnt work lol. this is getting frustrating.

 

anyone else?

 

it seems like you've done everything to get it to work again.

you did reset it right?
you cleaned it out with brake cleaner.

maybe, just maybe try a bit of a smaller gauge vacume line? IM JUST THROWING THAT OUT.

if that dont work, scrap it, its not like its all that expensive

 

did you clean the holes under the O rings? It's just about the most simple BC design ever so if it doesnt work it's probably still dirty.

 

or you have it hooked up backwards....

 

yes i removed the rubber "O" ring and cleaned the 2 holes, and you can see in the pic, its not hooked up backwards.

 

stupid guess but have you checked the vacuum line going to it? maybe its cracked or has a hole in it.

 

ya ive tried smaller vacuum lines with the same result

 

wether it be a ball and spring or a simple vlavle, if its not working, then somethings not letting air threw.

There arent that many possibilties, wether it be the vaccum line outlet or the controller its self, but something is not letting air pass.

 

if its a ball type it looks like its hooked up backwards...

your boost source should be pushing against the ball bearing trying to get INTO the MBC...

the way you posted it, it looks like the boost is entering the MBC through the exhaust hole (that should be going to the wastegate)...



then again i have no idea if your MBC is valve or bearing style...

hope the pic makes sence

 

Have you tried switching the vacuum lines? It's been awhile since I messed with a MBC but they look backwards..

*edit*
nevermind i just look thru my old pics of my setup with the same mbc and it was routed the same except the boost line came from a vacuum manifold,but that shouldn't make a difference...

 

I had the same problem with the exact boost controller. I use to have a 7lbs spring in the wastegate and was trying to turn it up to 13lbs. It'll just boost 15+psi and let it off. After one day of messing with it and not getting it to work I just brought me a tial 13lbs spring and call it a day. I have seen alot of people that didn't have good luck with the same boost controller.

 

I have fixxed many of these what it seems to be on the versions like yours, high performance, and especially on the 2-stage boost controllers. when you get liquids like engine cleaner, gasoline, methanol, pb blaster, brake clean, any kind of harsh cleaner like these eats away/dries out the white o-rings. when they are gone everything leaks. try replacing all of the white o-rings with some regular black ones from your local hardware store. This may not fix it in your case but I have done this with 10+ of these things and they have worked flawlessly from then on after having the EXACT problem you are having.

 

Bumping this old thread because i have the exact same problem. I took mine apart and put white teflon tape on all the threads because it was leaking.. now its running essentially open turbo >.<

I have a set of a/c line gaskets, ill put those in and see if i can get this thing going.. maybe when i put it back together i put the ball on top of the spring and not on the bottom.. hmm


Woot for my first post in like a decade. ha

 

In the picture its installed backwards, If yours is like that it will not operate. Pressure line on ball side (bottom), Wastegate on side port

 

The ball goes in first on the bottom, then the spring. Also be sure you put the o ring back in.
And as stated above, pressure reference is the bottom port and wastegate port is the side port

All wastegate of this kind are the ball/bleed type, so make sure the bleed hole isn't blocked by debris.

Also, too much Teflon tape can be bad, it could be blocking a hole, causing the ball to stick, etc.