Boost leak? Boost gauge misreading?

[97gsexx]

Just finshed putting the spyder back together. It is a 6 bolt 2.3 stroker with wiseco/crower pistons & rods, 2g head with stock valve train & springs w/ fp2 272 cams, new gaskets, with only 5,000 miles on the setup. When doing a boost leak test, the tank is set to 25 psi and seems to be holding boost. I have it at 30* past tdc and I still hear air exit exhaust. The boost gauge reads 2 psi when doing the blt. I fixed all the leaks I could find/hear (soapy water method). Just replaced injectors and seals/o rings. I don't hear any leaks and it holds pressure for 30 seconds+ when when I stop adding air. I am using a 29 gallon tank, and my tester doesn't leak.

I got the car last Friday and it had a bad boost leak that was not allowing it to go into boost when driving. He did a compression test and it all checked out. I just put in cams, 3g lifters, replaced timing belt, vc gasket, injectors, turbo, exhaust, pr mvs wastegate setup dumping to atmosphere, intake, valve cover, link v3 full, and afpr.

Boost gauge could be off? It's a practically new prosport boost gauge. I have an autometer I could throw in. Lines look fine. The boost gauge should read similar to the pressure the tank is showing, correct? Intercooler couplers are very tight, no leaks. Possibly bent valves since air is escaping through exhaust while at 30* tdc?

I am going to do a compression and leak down test tonight after work. Any advice on what to test would be very helpful. Thanks in advance.

[Shane@DBPerformance]

Leakdown test should tell you if it's a valve problem.

[97gsexx]

Yeah I will be doing a leak down test tonight. Also, I have been doing some reading about the pcv valve. When I was doing the blt, I had the hose connected to the pcv valve. I am going to try plugging the hose and seeing if the head is still getting pressurized. If the pcv valve is letting air through, it would make sense why the air is escaping through the exhaust.

[97gsexx]

However, should air even be able to pass through the valve stem seals on the exhaust valves? I would think that the bad valve stem seals are the only way air could enter the exhaust manifold during a blt. Is this correct? I just don't understand how air could pass through exhaust unless the seals were leaking, thus allowing air pass through the exhaust manifold. I would believe it would make sense if the pcv was allowing air to pass through the vc. If the pcv is not leaking then I have no idea how the air is even getting in the head in the first place. A leaking pcv puts air into the crankcase, not the exhaust. Maybe I just don't fully understand how the valve train works.

[4seasons69]

I'm extremely confused. Are you doing a boost leak test or a leak down test? Where you say you set the tank at 25psi you only filled your air compressor tank to 25psi? Also if you're doing a boost leak test and you have the cams in and timing belt on no matter where you have the crank there are going to be intake and exhaust valves open. Air will be flowing through the turbo, intake, engine and exhaust.

You're probably seeing little on the boost gauge because you're not filling your compressor enough.

Idk I'm confused though so maybe I misunderstood what you're talking about

[97gsexx]

Sorry I suppose I could have worded it better. I meant to say during my blt I had the regulator on the tank at 25psi and charging the system from the turbo inlet only allowed 2psi to build inside the system. I did a little more searching and found the EGR was attached. I believe that to be the reason why my exhaust was getting air and not allowing my intake to hold pressure during the boost leak test. Now I just need a block off plate