94 5.2L Magnum running rough

You may have just 1 bad spark plug, (Or wire) if you checked all those other things & they checked OK. jos51700 is correct about the coolant temp sensors too, (Up until 96, that's when Chrysler went to OBD2) but 1 (with the single wire connector) is for the temp gauge & the other one (2 wire connector) is for the computer & that may be bad, causing a problem. My first guess, try a fresh plug in #4. That's probably all it is.