Q: My car does not accelerate when I throttle, instead it jerks back and forth.

Diagnosing throttle issues is very difficult to do without being on site to complete an exam. However, in some cases, this symptom is caused by a damaged or worn out throttle controller. Throttle Controller is the electronic version of what used to be operated by a mechanical cable. As you press down on the accelerator pedal, the throttle control cable pulls on the linkage described above which is connected to what is often times referred to as a “butterfly valve” inside the throttle body. If the action in which you apply pressure to the throttle changes the performance or acceleration of the vehicle (as you described above), this is usually the source of the issue. If you need a more definitive diagnosis, have a certified professional, like one from YourMechanic, inspect the acceleration problem and advise you on the correct repair.