Kia 2006 Sedona 3.8 v-6 acceleration surges -

My friends have a KIA 2006 Sedona with 3 or 4 very bad hesitation surges when accelerating from a standing stop. It runs like a dragster when passing from 30 to 60 so I don't think it is a fuel filter, fuel pressure, ignition coil problem but my tech skills currently stop at the 1995 level, ha ! I am a home mechanic, several engine rebuilds, and would like to fix it for them but I understand there are over 400 sensors in these vehicles now, so I am told. I suspect a faulty input sensor but could use some guidance on this one. I am willing to purchase a diagnostic reader if there is no way to extract the engine codes without one, at my own expense, they are very good friends to me. Can you help me with this one or point me a direction to take? Thank you in advance for any help or time you give to this, solution or not. Jim S.