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Boost Problems

869 Views 11 Replies 4 Participants Last post by  Slave_1
G
I am having some serious boodt problems with my stock TT. From a roll, anywhere between 40 and 80, if I floor the throttle I don't get any boost (2-3 psi) but, if I give it 1/4 to 1/2 throttle I boosting at about 8-9 psi. Off of the line it does great until abou 4-5 K rpm in 3rd and then boost falls off again. Also I never boost above 9 psi.

Anybody have any ideas what the problem might be? Wastegate? Failed 2nd turbo? I have no top end and it really sucks.
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Sounds like a boost leak to me..
G
Dude, not trying to hate or anything, but is this the most universal answer to any turbo problem?

I don't think that it is a boost leak. I don't think that the second turbo is even spooling. By the way, which turbo is number 2, the front or rear?
It's the rear one.
I had a similar situation late last year and it turned out to be a small vacuum hose to one of the turbo VSV's that popped off. It was located at the front of the engine just above and to the left of the water pump as you stand in front of the car facing the engine. Your problem is probably not the turbo but one of the small vacuum hoses. Hope this helps.
Wingless said:
I am having some serious boodt problems with my stock TT. From a roll, anywhere between 40 and 80, if I floor the throttle I don't get any boost (2-3 psi) but, if I give it 1/4 to 1/2 throttle I boosting at about 8-9 psi. Off of the line it does great until abou 4-5 K rpm in 3rd and then boost falls off again. Also I never boost above 9 psi.

Anybody have any ideas what the problem might be? Wastegate? Failed 2nd turbo? I have no top end and it really sucks.
Have you seen any oil or discolored smoke?

If so...... :(
G
No excessive oil or funky smoke.
G
Lonestar Dawg said:
It's the rear one.
I had a similar situation late last year and it turned out to be a small vacuum hose to one of the turbo VSV's that popped off. It was located at the front of the engine just above and to the left of the water pump as you stand in front of the car facing the engine. Your problem is probably not the turbo but one of the small vacuum hoses. Hope this helps.
Thanks man!

I did find a small vacuum line loose and that did help. I'm still only pushing 9 psi though.
i guese number two is not comming online. do the ttc with check valves...it might be the vsv's not working. my $.02
WINGLESS, i just had the exact same problem on my TT and traced it to that vsv line just mentioned and another vacuum hose on top of the engine. It seems that when running higher than normal boost settings, these lines tend to come off. I am going to put a brand new set of blue colored vacuum lines that will eliminate this problem. Hope this helps... :)
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Thanks for the help guys. The problem was the vacuum line going into the top of the IACV. I just put a new one on to make sure it doesn't pop off and the dawg runs great again.
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wingless,

could you give me a description of where this vacumn line is? i am having a similar problem and have begun to replace hoses, but still am having the problem, it may be one that i have not gotten to yet.
G
sorry,

i also see that you live in CO. where are you located, i am at 120th and I-25.
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