Q: Jerking reaction

Hello, There are a few things that can typically cause a car to have a bit of a jerking reaction when driving. Low transmission fluid can cause this to happen when the transmission lacks sufficient transmission fluid required to build enough hydraulic pressure to cause the transmission to shift properly. Another common cause of this kind of symptom is a dirty or faulty mass air flow sensor. The mass air flow sensor monitors air intake as it is mixed with fuel prior to being injected into the motor. This sensor relays vital information to the ECM which uses this to make adjustments to fuel supply to the motor. A dirty or faulty sensor can cause an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This type of inconsistent fuel supply to the motor may cause a hesitation, loss of power, a jerking reaction, potentially a bit of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning. I would suggest having a professional from Your Mechanic come to your home to diagnose and inspect your vehicle.