I would start off with the simple stuff. Run a can of BG 44K through with the next tank of (quality) fuel. Check all of your spark plug leads: make sure they are intact, boots are good, no water under the boots. When you reinstall the boots, pack some dielectric grease in them. Check the lead that runs from the ignition coil to the distributor and do the same thing. Make sure all of the spade plugs are secure on the bottom of the coil.
Try these things first. If that doesn't fix it, come back and we can go over the next steps (fuel filter, fuel pump issues, throttle body cleaner, etc).