I have a 1986 RX-7 it runs great up to 3800 rpm and then begins to spit and sputter and fall allover itself. Every once in a while it revs clean to 7000 but 95% of the time it will not rev higher than 3800 rpm without major sputtering and stumbling. And i was tinkering with it today and finally got a clean run to 7000 rpm after 20 minutes of driving around and trying, so i finally got to see what my car felt like in higher RPMs but to my suprise there was thick white smoke coming from my exhaust from 3800 to 7000 rpm, it was definately oil smoke. does anyone know what may be causing this stumble? Or what caused the thick white smoke to happen when it finally didnt stumble?

 

search for the 3800 rpm hesitation