E-150 4.6, automatic, starts easy, idles ok, cold, in park, but engine runs very rough when pressing fuel accelerator in gear or not, not driveable as is, shakes everything. On/about 189k miles, plugs replaced 1 years ago. vac hoses & fuel return hose replaced, fuel additive/dehydrator added, engine light on. Problem did go away one day, drove to fuel station added 5 gallons new fuel, drove a couple of miles, things seemed ok. After sitting a week, same problem as described above. What now? Thanks

 

Did you do anything with/to the fuel filter?