First thing is to make sure you have fire (spark) at the spark plugs. If not change the ignition coil.
a worn valve will make it back fire
Flint and Steel can be rubbed together to make fire.
NO SUCH THING. They are CORE plugs used to make the castings.
Old spark plugs can make a car misfire, run rough, and not fire at all.
Make sure you are using Ford OEM (Motorcraft is not always OEM) Spark Plugs that are designed for you explorer.
It can be the ciner on bellhousin or bad coil
Start with the basics. There are two things needed - Fire and gas. Fire being electrical power, make sure there is fire to your plugs. Gas make sure it is getting gas to the carburator. Search both pathways to your problem.
this is an easy procedure simply locate the plugs, remove the plug wires they should just pull off(make sure you label these in some way so that you know which goes where) , and using the spark plug socket from your average socket set and remove the sockets and replace with new ones then replace the plug wires on to there corresponding plug make sure you do not mix them up or the plugs will not fire in the right order
The friction caused by rubbing the sticks together causes heat causes the fire
Oxygen and friction.
i dont know what size and make spark plug should be used 222