i have an 84 gn with stock motor i got used and will build some boost the slows and blows black smoke and seems to miss. prev owner had 87 comp with reds 93 chip,87 coil adapter and hotwire kit with a pos walbro pump. i didnt get any of the eng stuff so i had to use the 84 comp,down pipe,coilpack,fuel reg,but have test tube with 87 kenne bell exhuast.didnt have any codes until i started the other day and had esc code.any suggestions?thanks andy