[robb15033]

To put yourself on a level playing field you should use the Seafoam treatment. It will clean things up and eliminate some possibilities that can distract. Directions are on the can and website. A can cost under $8.00 at parts store. Suck one can up through pcv valve system and one can into gas tank. Repeat until no smoke from exhaust. Our V6's accumulate an excessive amount of vapor that condenses inside upper intake manifold. So if your mechanically incline, suck a bunch of the cleaner through any/all vacuum lines while someone keeps the throttle car running.
Make sure proper spark plugs are in there. Autolite/Motorcraft/NGK Copper Core Resistor work fantastic, just don't last as long as platinum or iridium.- Just FYI