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View Full Version : Boost Leak Questions/Help


NiteRaven
08-04-2006, 09:57 PM
Hey all,

I've been spending the last week searching for boost leaks on my stock turbo setup (redtop SR). The problem is I'm losing a lot of power (bucking and sputtering) in the high end boost around 7psi... but sometimes less. If I let the boost creep up slowly it doesn't sputter as bad, but it usually will at the very high end. If I give the car full throttle it'll buck like crazy.

I think I've narrowed the problem to a leak somewhere but I cannot find it. Coil packs, timing, FPR, spark plugs, MAF, TPS, and ECU all tested OK and within spec.

I've tried to pressurize the system but I only have a crappy electric pump that can pressurize the system to 3 PSI before the air finds a way to leak out through the oil dip stick or other wierd places (it pumps pretty slow). I know I need an air compressor to test for tiny leaks but I don't have one. I've managed to find and patch a few bigger leaks around my BOV and intake rubber hose and that seemed to help a little bit. I pretty much hit up every spot it could leak with a water bottle.

Also when I installed a Nismo FPR that seemed to help smooth things out a little bit too. Leading me to believe I was running a little rich to begin with and probably really rich with the leaks added. I have a walbro fuel pump. (although it idled perfectly, no smoke at all)

So any ways, my questions:

I'm getting really nit picky, trying to fix what I can.

1) Is it necessary to clamp down the end of your vacuum hoses that go to the throttle body, wastegate, boost gauge and what not? I do not think it's leaking from those spots, if it did I figured the hoses would pop right off. Then again I suppose it could leak from there around 7psi.

2) Has any of the information I've given hinted at where the source of these leak(s) could be? I'm really thinking it's around the turbo itself at this point but I'd really hate to spend 5 hours taking it off and doing all the gaskets to find it was not.

3) Have any of you heard of a smoke test that searches for leaks? I heard shops can do the test pretty cheap.

I guess I'm getting desperate at this point... I wish I had an air compressor. I've spent a good 50 hours narrowing down and testing what I could. If you guys don't have any suggestions for me I'll break down and get an air compressor.

Thank you!