The only time I've had this happen is when I've tried to use too much end point travel. have you already set your EPA for much past 100%? if so, this is your problem. As suggested, reset the endpoints to 100% (high and low) and then fix it mechanically so that it will travel as close to both ends as possible. Then FINE TUNE the travel with the EPA--and try to get as much EPA on the bottom as the top. In other words, if you have 80 on low, then try to make it where 80 on high gives you full throttle. Again, much of this is accompllished through mechanical setup. having it close to the same on both ends helps give you more of a linear (proportional) feel to the throttle movement.