Boost valve problems ?

[rcfts]

I just got the car running a few weeks ago , the other day I gave it full throttle , and I whent full boost till fuel cut . It happened really fast . So I've been messin around with the valve anD ware gate all day . I know my waste gate is working as designed . If I take the valve out of the line and apply pressure with a hand pump the waste gate opens at about 14psi . As soon as I put the boost valve back in the waste gate line , I can not get the waste gate to open with the hand pump , no matter what setting the valve is on( top screwed all in/out ) . It seems to almost instantly bleed air out of the vent hole . Have I done something wrong ? I realise this is my first turbo build ever , but this valve is extremely simply designed . I don't think I'm missing something , but I could be ?

[Stinger]

Sounds like the valve is either installed backwards, or you're adjusting it backwards.

The valve should have the line from the "side" going to the wastegate actuator and the "bottom" coming from a boost source (turbo, vacuum tree, intake manifold, etc.).

When adjusting the valve, all the way "out" is the lowest boost setting and all the way "in" is full boost.

[rcfts]

The valve is not installed backwards . No matter what setting it is at , all in or out, especially all out , the waste gate never opens with any pressure from a hand pump . I cam pump it up to about 20 psi but it bleads off instantly out of the vent hole . It doesn't even try to hold pressure( not even 5lbs) with the adjustment all the way in .

[Stinger]

Pull the adjustment cap, remove the ball and spring and make sure the ball goes in first, then the spring.

I also assume the valve is installed so the adjustment cap is at the top, not the bottom (gravity working against the spring)?

[rcfts]

the ball is installed correctly. with it installed so the ball end is down it still wont open the waste gate on the minimum seting . do you think it may be that i have a not factory 14lb waste gate ?

[rcfts]

so i think i got it under control . i dont think the hand pump method was the ideal way to test it, i did not want to over boost again (car has not been running for even a month ) dont want to break anything just yet. so i installed it back on the car , adjustment all the way out , got about 15psi on the guage, adjusted it in till i got a good 16-17 psi . is i normal for it to spike ? every once in a while ill spike to about 20?

i really appreciate the the KIND and QUICK responses to help me figure this out !!!!

thanks again
Chris

[Stinger]

Good to hear it is worked out. What did you change?

Sometimes you'll get a little spike right as you reach peak boost. This is typically related to an oscillation of the spring before it settles into position.

[rcfts]

i think i initially had it installed backward,(very embarrassing to tell you that ) . like i said this is the first turbo motor that i have ever dealt with, for fun. (let alone built ) i have a huge learning curve ahead of me and know no one locally to whom to ask questions to.

so having it hit full boost on the very first time i held the pedal all the way to the floor kinda made me paranoid that it would do it again, so i tried to "bench" test it to save my motor from experiencing more over boost. well i also found out its really hard to bench test that valve

thanks again.

[Stinger]

Nothing wrong with installing one backwards...as long as you catch it before it causes damage. I've seen probably 100 or more people admit to doing so over the years. It's pretty common (and why that's the first place I went with diagnosis).