Boost leaks!!

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Aug 10, 2017 | 05:44 PM

97-psd

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From: knoxville, tn

Boost leaks!!

I have felt for awhile that I have a boost leak. I built a handy dandy leak detector last year but just around to using it today. I found a seemingly big leak from the turbo to the Y pipe. New gasket and all is good there. Found a leak at the map sensor. New clamp fixed that one. Amazingly the plenums do not seem to be leaking. I have a gauge on the leak tester and it never got above 10-15 psi. Is this normal? I expected to build about 20psi and maintain it for the test. I do have a fair leak at the CCV doghouse, which I didn't think would be abnormal. I just expected to build more during the test. I don't have the biggest air compressor, but it is a 30 gallon belt drive Speedaire. It normally supports any air needs pretty well

Aug 10, 2017 | 05:51 PM

madpogue

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Joined: Oct 2003

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From: Madison, WI

Isn't there a way to install the leak detector further downstream, past the CCV?

Also, something I've wondered about wrt. boost leak detection - with some four-cycle engines, there's a phase at the end of the exhaust stroke / beginning of the next intake stroke where both valves are open. I ***THINK*** if one of your cylinders is in this state, that would have an effect on how much pressure you can build. I just don't know anything about the valve/cam mechanics of the PSD, so this is speculation.

Aug 10, 2017 | 06:45 PM

97-psd

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From: knoxville, tn

Good point.
I just had a thought, I have some carb port plugs. I bet one would fit over the the prong inside the intake. If that doesn't work I may need to get an adapter and get past the CCV and see if I can build more pressure

Aug 10, 2017 | 09:58 PM

knottyrope

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From: Bahstun

Can plug the exhaust pipe during the test if a Valve is open

Aug 10, 2017 | 10:01 PM

madpogue

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From: Madison, WI

^^^ +1; good idea. Or unclamp the downpipe and plug at the turbo exhaust outlet. Less volume to fill that way.

Aug 10, 2017 | 10:58 PM

7.3 forever

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Joined: Aug 2014

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From: piedmont mo

I took intake completely off put a cap on the intake and unhooked my map sensor line and put my air blower in line and had someone watch my boost guage I only pulled trigger half way and pegged my boost guage out which only goes to 30 psi