In the searches I found, I see alot of fluctating boost patterns. but mine seems different. I borrowed a boost gauge (mines on order) and I saw what I was feeling...
10psi on primary and at changeover it quickly drops to 5psi, and never changes. the car had a secondary boost problem before, that was fixed. *before I owned it. I got under the car to inspect any loose vacuum hoses and saw nothing. There was a small amount of oil on the bottom of the turbo. So am I to assume that the CCV, Pre Accuator and the usual suspects are to blame?
I hope someone can shed some light on this. Also, what is the web site for that ISTAR? I cant seem to get in it with the bookmark I had saved. THANKS!

 

dayem... no luv ~ yet.

 

I'm havin the same problem, i've been told it is probably the TCA solenoid. It's supposed to be a $60 part. To test if this is the problem, accelerate in 2nd until the 2nd turbo spools, floor it, let off, and floor it again. If you see boost go up to where is should be, it's the TCA solenoid, and dontbearikka.com has a good picture of it. Good luck.

 

I need to do change the vacuum hoses. I wonder if Ill solve it when I do it then.
*and any potential 2ndary boost problems that tend to occur with the vacuum controls. Someone mentioned to me a plugged cat, which cat Im not sure.
but Ill take one off for the hell of it and see if I can peek in it.

 

the pre-cat is known to clog up. if you don't already have one then i'd get a dp. keeps the temps down under the hood and you don't have to worry about the pre-cat clogging. check your main cat too to see if it's clogged.
nick

 

This is quite a common problem.

Check here if you haven't already:

http://www.autosportracetech.com/RX-7/rx7stuff.htm

My guess is that something in the turbo control system is not working. The turbo control system consists of the turbo control actuator, 2 turbo control solenoids (one for pressure, one for vacuum), the pressure chamber, the vacuum chamber, and lots of hoses connecting them all.

I would systematically start checking each of these things. Make sure you have the good colored hose diagram (can someone post a link?)

Of course, it could be something completely different