I have a 1994 ford explorer

Sounds like a engine miss. Probably needs a tune-up.

You can check your coil with a multi-meter, get the "how to" from the web along with the specs. From experience I have learned if they are even a little out of spec the engine runs bad. I suggest motorcraft as OEM brands are often out of spec for Ford out of the box. You can also check the resistance of your plug wires with a multi-meter. Use Motorcraft for plug wires and plugs. A little more expensive but you will appreciate it.