summers pitbulls

here is what i did i tacked it up in first and second gear i hit third and half way through about 5000 rpm my motor stared to spit and sputter it dont smoke i pulled all the plugs out and they all were geting fire the compression is realy good i look over all my vacum lines all good it still starts right up but it reves realy slow . it is a s5 turbo ll on a 91 conv. i dont know what the problem is im lost