I just bought a "new" 2004 Trailblazer EXT with 105k miles. If I want to accelerate quickly from a stop for merging onto the interstate, for example, I am gradually pushing the pedal down more and more to try to get the rpm's up, but it seems like it just accelerates at the slow pace it wants to until I get to certain point (maybe pedal halfway down) and then all of a sudden the rpm's shoot way up and accelerates faster than I was intending. Is this normal for these TB's? Or could it be a faulty pedal sensor? A faulty throttle position sensor? A dirty throttle body? The engine otherwise idles perfectly fine and I have no other noticeable symptoms. I searched around the forums, but couldn't spot an identical scenario from someone else. Thanks for any tips.