Q: After putting a new alternator in why would my car start jerking while trying accelerate?

If you disconnected the battery during alternator replacement, you might have lost some of the initial settings in the car’s controllers. If that’s the case, things should start working better after you have driven the car a few times and the system "re-learns" some settings. Another possibility is that the output from the new alternator is not consistent or it is overcharging. some of the replacement alternators sold by the discount parts stores are of very poor quality and it’s not unusual to have a problem right from the start. Or it could be unrelated to the alternator and something else entirely. If your car isn’t working better in a day or two, you should have it checked. You can have that conveniently done by contacting YourMechanic. They will send a technician to your home or office to check out your Ford and let you know what is up.