Possible boost leaks

[Studduck]

I want to know EVERY possible cause for a lack of boost. I cannot get as much boost as I could when I got the car (it was hitting 8-9 psi). Now it gets around 4-5 psi. Mods: 3 in. dp, 2.75 in. exaust, gutted cat, and k&n air filter, lightweight flywheel.

Here's what I have checked already:

BOV is fine
**Vaccum lines are fine (havent checked all of them)
Intake clear of obstruction
IC pipes look good
Very minimal Shaft play
turbo spins easily
car runs GREAT (other than lack of boost)
cat is gutted (so thats not a problem, hehe)
Turbo gauge is fine

** I havent checked them all (vaccum lines), but I can feel less power when I'm driving so I dont think thats a problem.

Things I havent messed with:

AFM
ISC
Nipple thingy on intake manifold

I'm not really sure how to check the above... any advice would be awesome.

One more thing... My buddy blew into the the 3000 pipe and we heard air moving somewhere around the oil cap and the alternator. Could that mean anything?

I have spent a lot of time trying to figure this out and its getting really old!! please help me


What else can I check?

 

[swaq]

*bump* When I drove it I think it was getting up to about 6 psi.

 

[aye mate]

Check the TB coupler.

 

[xarewhyayen]

http://www.supramania.com/forums/showthread.php?t=19718&highlight=boost+leak+tester

^go there.

 

[Studduck]

I built a boost leak tester a while back, and we pumped it with air. It wouldnt hold any psi, but I think that might be because of a few things:

We connected the tester to the accordian pipe, and not the actual turbo.

The boost leak tester may have a leak.


But this is when we heard the air moving near the alternator and the oil cap, is that normal? or is it just air entering the engine?

 

[aye mate]

You're just using the tester wrong.
The air is escaping through the air filter. You need to take the accordian hose off totally, put a 3'' cap on the mouth of the turbo and then hook the tester into the BOV port and pressurize.