You're not alone and it's a really interesting control problem. The whole loop, including the driver's reactions, appears to be unstable and probably underdamped. Stronger springs seem to have helped some people. I'd start by checking that the operation of each bit, and especially the cable, is smooth and that the angles of the cable in the pedal box and at the throttle look right, especially at small throttle opening. The other trick that's been mentioned is leaning your R leg against the wall to create some damping in the loop. Jonathan