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Q: Jerking reaction

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My car just started jerking forward right when it reached 50 mph. What does that mean?

My car has 104130 miles.
My car has an automatic transmission.

Hi There, The jerking reaction you describe may be related to a few things such as a faulty or dirty mass air flow sensor, a bad fuel pump or possibly a vacuum leak. 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.

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