Hi
I had problem with the old throttle body in MPI , sometimes hanging the RPM and not going back and I have to push the pedal to go down (when the engine hot) the issue with the butterfly rub the plastic, I changed the TPS and the accelerator cable is same issue.
At the end the issue was with the same throttle and I found the genuine one last piece and fix it in my car and now is perfect :) I know the SU company develop the throttle body and now is metal but I prefer to keep car original
the topic to share my story with the throttle :)
Regards,