I've been having a misfire issue with my 4.7 and running Seafoam through the fuel system and vacuum line seems to have cured it for the time being. I have a thread going right now if you want to read through it.
Sometimes an injector can be clogged and the Seafoam can help break that stuff up and it will begin to run better. I put some in the oil as well and it may have cleaned valves or ports that had build up. Anyway, it worked. You may have a similar problem. After I ran everything through it took 50-75 miles to go away, assuming it took some time to break down build up and clean everything out.
Last edited by bpark8824; 12-29-2011 at 02:37 PM.