mini monster

i have a k20 mind engine swap in a 1965 austin mini. Super charged. Was running great until i really got on it. Now its showing signs of a tps problem. i had a omni tps changed to a ktuned and just exchanged it for another ktuned. but problem is still a problem. this is the problem car idles perfect but as soon a u push the throttle at 1/8 of the way down the rpms surge up and down. causing the car to buck so bad u cant drive. i calibrated the tps to .45 tested all connections. if u look at it in kpo the tps does not move and is at 0% at close and full throttle. so to temporary fix i jumped the single wire and the power on the tps and car runs fine just idle is a little high but not looking to keep it like this looking for a perm fix not a rig