My 93 RX7 has inconsistent performance above 5500 RMP or so. Basically it runs strong until 5500 and then tapers off as if there was a partial fuel cutoff. On the other hand, sometimes it runs strong to 7000. When it runs right, I feel the second Turbo kick on hard. When it doesn't run great, I'm not so sure.

Any thoughts?

 

Do you have a boost gauge to monitor your boost pattern? Sounds like your boost may be falling off sometimes, prob. due to solenoid problems. Can you expand as to "tapers off as if there was a partial fuel cut off"? Exactly what is the engine doing when this happens?