Apologies for making these threads, I've been studying the FR for years and I cant seem to find the cause of it.

Directly after clutch engagement, most pronounced in first gear, less pronounced in second, and so on, the throttle plate angle surges up above the accel pedal angle and then drops back down, where it remains, less than.

Does anyone know what could cause this? It's been happening since I bought the car, stock unmodified and has become more pronounced with modifications.