Why does car hesitate on quarter throtal?
Year, make, model and engine size would help us help you.
You can take this with a grain of salt but I have the same problem with my tb and I beleave it hesitates because there is no cable linked between the foot pedal to throtal body. Its servo controled. Look under the hood and you'll see what apears to be an electric motor attached to the throtal body. Only my opinion and don't no if I'm right.