We have a 95 WRX STi RA (yes it is fair dinkum) it is a grey import, so not a lot is know about it, it used to live in Canberra and looks like it has been rallied in Aus and Japan. We rally it now and run autocross in the Victorian Club Autocross Series, 2nd outright 2008 & 2009. As far as we know it is bog stock standard STi RA.
The problem is that it has been losing power little bit by little bit. The intake was full of dust which I have since gotten rid of however it is still not fixed. It never had a boost guage so I put one on today and it is reading, at best, 5 PSI boost at about 6000rpm, and this boost seems to come as a spike, this was meastured from a tee at the vacuum / boost line on the cmpressor outlet. Below that it produces nothing, which is how it feels to drive also. With the boost guage connected to the intake manifold downstream of the throttle body it mostly reads vacuum or nuetral.
I think I have read nearly every post on every forum I can find and all of these point to the wastegate as the problem. I pulled the heat shield off, ran the car again with the boost guage in my hand and watched the waste gate actuator as the revs built. Nothing, not the sightest movement and the actuator is holding the wastegate firmly closed. With this failing, I pulled the actuator arm off and held the waste wastegate closed myself. No change, still 5 pound boost as huge rev's. Not much change if I opened the wastegate either.
So, in desparation I pulled the turbo out today hoping that something would be wrong with the wastegate. Nothing seems to be wrong. It opens and closes very freely without the arm on and seems to seal on it's mating face. There is a tiny (less than 1mm) bend on the corner of one compressr wheel blade but other than that I can see nothing, there appears to be no free play in the wheel at all.
The other weird thing is that in every diagram I have seen the wastegate actuator runs off a tee off the vacuum/boost line at the compressor outlet that goes to the boost control selenoid. The vacuum / boost line in ours goes directly to the boost control selonoind, the line to the waste gate actuator comes out of the BCS as does another line to the intake just after the MAF sensor. There is a heap of other "selenoid looking" things around the BCS selenoid that I do not understand and have not seen anywhere else. One has one vacuum line going in and 3 wires coming out???
Please help, I have no idea where to go to from here. This is the first turbo car we have ever had and it has run trouble free for 3 1/2 years (Don't worry, so would yours if it did less than 500k's / year) so we have not had to do much work and not had to learn too much. Now we are in trouble, I can't win a race to save myself, my wife's Liberty goes nearly as hard!
Anyone that can point me in a sensible direction or can point me to a reputable, cheap mechanic in SE Melbourne would be appreciatted. I prefer to work on it myself rather than spend money but I am at witts end and are supposed to be racing Saturday.