My 89 MTX is running rough. Sometimes it smooths out with RPM, and most of the time it smooths out right at 2600 RPM and sorrta feels the same as the secondaries opening. I ran the KOER test and in the "SEFI or Cylinder balance test" it reports cylinder #3. Later tonight if I have time i'm gonna start looking in to it, if not I will in the morning. I'll let you know what I find out and if there is anything else wrong. If you can think of anything I should be specificaly looking for please let me know.