I think your going down the right track, first thing to check would be the injectors. Have you checked your spark plug wires with a meter? If not do that too.
2005 Jeep Grand Cherokee 6.4L (The beast) (Fastest lifted WK)
2012 BMW X5 Turbo'ed (The b*tch)
1998 Jeep Grand Cherokee 4.0L (Ol' reliable)