The 5.4L engine in your Ford vehicle uses a direct ignition system equipped with an ignition coil over each spark plug. This eliminates the need for wires between the coil and spark plugs. Although you have fewer parts to maintain in the ignition system, problems with worn out coil's windings or internal circuit may result in a weak, intermittent or lack of spark. In this case, replace one or more faulty coil packs as needed without having to change the whole set of coils.
Open the hood and take off the air intake assembly from the top of the engine and the power-steering reservoir mounting bracket with a ratchet and deep socket, if necessary. This gives you more room around the coil pack you need to remove. Move the reservoir to the side but do not disconnect it.
Locate the coil pack you need to remove. Each spark plug has a coil mounted on top. Unplug the electrical connector from the coil pack. Unplug the fuel-injector electrical connector next to the coil pack, if necessary.
Unfasten the single bolt holding the coil pack to the engine block with a ratchet and ratchet extension and socket.
Pull up the coil pack carefully from the spark plug.
Install the new coil pack making sure the coil boot fits with a snap over the spark plug.
Fasten the coil pack single bolt with the ratchet, ratchet extension and socket.
Plug the coil electrical connector and the fuel injector electrical connector, if you had to unplug it.
Replace the power steering reservoir and air intake assembly, if you had to remove them, and close the hood. Use the ratchet and deep socket.
