Trying to diagnose a Ford engine that is running rough can be a tricky proposition. However, it is important to determine why the engine is running roughly, because running a vehicle like this for a sustained amount of time can cause permanent damage. There are several ways to determine if the coil packs are causing this issue, which makes troubleshooting the coil packs on your Ford one of the first places to start.
Misfiring and Stalling
When a vehicle has a weak coil pack, the engine will misfire. You can tell misfiring because your Ford will feel like it’s going to stall when idling. This means the engine will not run smoothly, but will sound choppy and the car may even shake. If more than one coil is weakened or not working, the vehicle may completely stall.