Not Boosting Correctly
04-07-2005, 09:30 PM
#1
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Join Date: Jun 2004
Location: Oregon
Posts: 131
My 87 TII is just not boosting correctly. I can see on my VDO guage 8psi, but it feels like 2-3psi. If I feather it and get it to hold, 8psi feels like 8psi and scares the crap out of me. 
I have checked for any vacume leaks (only 4 lines total) and checked for anything else I could think of. Do you guys think its my wastegate malfunctioning or what? Its a S5 turbo BTW. I am also getting a very large ammount of blow by. Right now I only have the 2 lines running into a oil bottle, but they are easily blown out.
I have checked for any vacume leaks (only 4 lines total) and checked for anything else I could think of. Do you guys think its my wastegate malfunctioning or what? Its a S5 turbo BTW. I am also getting a very large ammount of blow by. Right now I only have the 2 lines running into a oil bottle, but they are easily blown out.
04-08-2005, 04:22 AM
#3
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Join Date: Jun 2002
Location: WA
Posts: 1,312
lots of blow by like that at 8psi might be a bad sign. Do a compression check just to make sure you didnt break a part off an apex seal. That will cause blow by and account for your loss of power.
I've seen it happen too many times.
I've seen it happen too many times.
04-08-2005, 02:27 PM
#4
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Join Date: Jun 2004
Location: Oregon
Posts: 131
1500 miles on rebuild with everything new....RA seals.
Perfect compression all the way around (115,115,115 on both)
It does not hiss, however I am very suspect of some of these elbows and lines I used. I think I will tear everything apart today, clean it (oil got into the TID through the PCV system, fixed that with a proper catch can).
If I go from a dead stop, I can nail 8psi in first, 10 in second and have my rear end go sideways, and 10 in 3rd. Scares the crap out of me. Now if I try doing it lets say going 55 in 4th and step on it, I can build 10psi and have it feel like 1-3psi, and the car hesitates until it finds a place it likes, then kicks in and holds 10psi. If I cant find what it likes, the boost fades off.
Perfect compression all the way around (115,115,115 on both)
It does not hiss, however I am very suspect of some of these elbows and lines I used. I think I will tear everything apart today, clean it (oil got into the TID through the PCV system, fixed that with a proper catch can).
If I go from a dead stop, I can nail 8psi in first, 10 in second and have my rear end go sideways, and 10 in 3rd. Scares the crap out of me. Now if I try doing it lets say going 55 in 4th and step on it, I can build 10psi and have it feel like 1-3psi, and the car hesitates until it finds a place it likes, then kicks in and holds 10psi. If I cant find what it likes, the boost fades off.
04-08-2005, 05:26 PM
#6
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Join Date: Jun 2004
Location: Oregon
Posts: 131
[quote name='turborotor' date='Apr 8 2005, 12:36 PM']Check your turbo inlet duct right at the turbo entrance for any cracks.
C
[/quote]
I have a 2.5" peice of mandrel bent aluminum with a cone air filter, all the couplers are in good shape.
C
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I have a 2.5" peice of mandrel bent aluminum with a cone air filter, all the couplers are in good shape.
04-17-2005, 11:37 PM
#8
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Join Date: Mar 2004
Location: Puyallup Washington
Posts: 397
[quote name='fc3sna' date='Apr 17 2005, 08:10 PM']not to be mean but do you have a fcd, you said your hitting 10lbs
[/quote]
Thats exactly what I was wondering while reading this
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Thats exactly what I was wondering while reading this
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