300zx tt noob boost problem

[amaderojr]

OK I've spent hours doing research and am not being able to figure this one out. I just bought this 90 300zx TT, supposedly rebuilt with like 500miles on rebuild. ( just some background info). So I put a boost gauge because it just didn't seem as fast as it should, (I also own a Galant vr4 awd turbo, and that seemed to pull harder) and it is only boosting 4lbs. So I went through everything and noticed that it was put back together without a destination sensor, so I bypassed it until I can get a relocation kit. So now I have a code 55 but still only boosting 4lbs, so I disconnect the safe boost solenoid on the wastegate and still only 4lbs. So I try unplugging and blocking off the waste gate vacuum lines ( and I know this is very dangers so I ran 100octane to lower possibility of detonation) and what do you know its pushing 15psi. (Only ran it the once). So I want to know if anyone knows why its only pushing 4psi with the wastegate vacuum connected?

[ThisIsSparTTa]

Is this an TT Swap? You should have had a boost gauge on your instrument cluster under the tach. Also it sounds like time for you to get a boost leak tester: http://www.boostpro.net/prodz32tester.html

[amaderojr]

No, not a swap it has a stock boost gauge, I just don't trust stock boost guages lol. And I did a boost leak test because I had that problem with my vr4 as well. And with the wastegates disconnected it has no issue boosting hard. But I'll run another boost leak test. Thanks for the reply, I feel pretty lost with this, I'm always running into the weirdest issues

[t.mcginley.jr]

Sounds like it could just be bad wastegate actuators

[amaderojr]

How can I check that?

[Ace2cool]

From the tests you performed, that's what the signs are pointing to.