2001 Ford RangerMay 3, 2013My truck is running rough but is idle is just fine. Could this be a volt pack or spark plug wires? Share Tweet Pinterest Keywords:running rough 1 thought on “2001 Ford Ranger” Freeautomechanic May 3, 2013 at 9:08 pm It could be spark plugs, coil packs, plug wires, etc. However if a cylinder misfire often enough it will set a code letting you know the exact cylinder. This will trigger the check engine light. If your check engine light is on, I would suggest pulling the codes first before going further. You are welcome to post back the codes if you need help with them. Comments are closed.