wont build boost

[klcsmooth]

I need some help i cant get over 12 lbs of boost nomatter how short i make rod the same when i hit 12 lbs i hear like a hissing sound and boost wont go higher.What could this be?

 

[WhiteTtype989]

For starters what do your wastegate hoses look like any cracks ?

 

[klcsmooth]

good question i will check tommorrow

 

[Red C5]

Check all of your hoses and clamps to start.

 

[klcsmooth]

wont biuld boost

i checked all hoses they looked good still wont biuld boost and hissing sound.Changed turbo same thing i bypassed front mount ran tubing from turbo to intake ( i run alcohol) same thing.Could the wastgate be releasing pressure? What about the intake or head gaskets.I check for vacuum leaks I noticed a slight leak on vac distribution block on top of throttle body but i dont think that would cause boost failure. would it?

 

[EVIL]

exhaust leak maybe?

 

[ikle]

How old is the waste gate actuator ? I am wondering if there could be a problem with the diaphragm. Maybe you have a small vacuum leak in one of your vacuum lines going to your turbo,if you can get your hands on a "might vac" you can pinch off each section of vacuum hose and put it under vacuum to check for leaks.That is how I found several of mine,believe it or not even some of the band new vacuum hose I bought had leaks, even brand new tee fittings leaked.I am no expert but one thing I have learned about our cars is that a lot of the problems associated with them are usually vacuum or ground related.Good luck,ikle.

 

[ttaowner]

Cracked exhaust manifolds? I once had a turbo that wouldnt build boost and the nut inside the turbo was loose i figured it out once it fell off and wrecked the cold air side intake wheel.I had a crossover move before and let exhaust pressure out before too