I just bought a 91 Mr2 Turbo and I'm trying to work out a few kinks with the motor. Car idles fine and does great until the turbo spools to the point that the boost gauge reads about 3/8 to 1/2 of its full potential and the engine rpm is at about 3000-3700 rpm. At that point, the motor continues to rev, but the power band gets very sloppy and inconsistent.
My primary suspicion is a boost leak somewhere. The couplings are pretty old, but i'm not ruling out other possibilities yet. I would greatly appreciate it if someone with a boost leak tester and a little mr2/turbo knowledge could help me work through this annoyance.
Thanks in advance and feel free to ask for more specific info and i'll provide it if i can.