Not another boost problem thread
 

Hi This is my first post after much searching and have found much help but have not managed to fix the problem yet. I have a 92 fd bone stock, and i kinda want to keep it that way. When i bought the car i figured a seat of the pants boost test was enough to tell me the turbos were working. Well guess what, i was wrong. After driving it for a month i got a pod and installed a boost guage and found out my secondary turbo doesn't seem to work at all. First thing i did was take the compressor tube off to do a visual inspection of end play, And it's good, but i wanted to make sure it was good before i kept driving it.

Since then i have had very little time to play with it. But i bought a vacuum/pressure tester and printed off the autosportracetech troubleshooting pages and started working down the list. This is one of the more complicated and obscure systems out there and i would really like to figure it out, but it could take some time, it's a lot for me to wrap my head around.

Ok here's what my car's actually doing; Boosts up solid around 2000 rpm's or less, 11psi, And then as soon as 4.5k hits it tapers off, 8 psi, by 5 k 5psi, by 6k 0 to 2 psi, then nothing.

I got the idea to try a run from 5000 k with a vacuum condition (no boost) to see if this will spool my secondary turbo. Sure enough, Full boost 10 psi all the way to redline . So i'm led to believe i have a leaky vacuum tank/one way check valve. But i really don't know what i'm doing.

I have a dual pod and dual boost/vacuum guages until i get my problem fixed i figured the second guage might come in useful for troubleshooting.