What causes rough running in 1992 ford explorer xlt v6 4.0L?

Answer 1

Could be a number of things, cheap and easy start pulling spark plugs and check to see if there all consistent if any look like they have well worn electrodes replace them all. If plugs good depending on if its a rough idle or at all rpms, idle it could be idle air control valve or O2 sensor or about 20 other sensors so best to have scan done at local shop, especially if check engine light is on, just ask them to get code and the rest can be figured out. Fuel injector cleaner by seafoam is good product or marvel mystery oil good too if u want to clean fuel system and replace fuel filter, just a good thing to do if not done before "it is a filter" recc replacement every 50k or whatever