What would make a 99 mercury villager jerk and jump while driving and have no power but idle fine?

A 1999 Mercury Villager that jerks and jumps while driving but idles fine might have issues related to fuel delivery, such as a clogged fuel filter or failing fuel pump, which can lead to inadequate fuel pressure under load. Additionally, problems with the ignition system, such as faulty spark plugs, ignition coils, or a malfunctioning mass airflow sensor, could cause misfires during acceleration. Transmission issues, like low fluid levels or a failing torque converter, may also be responsible for the erratic behavior. A thorough diagnostic check is recommended to pinpoint the exact cause.