2002 Dodge Van 318 wont start out of nowhere

I was driving the van for 300 miles. No problem. Drive it the next day, and when I hold the gas about 1/4 throttle too fast it bogs down like it wants to stall. As soon as I let go it goes back to idling fine. If I gradually push on the throttle it will get up thru rpms with no problems. The following day it wont start at all. It sounds like it wants to fire but as soon as I let go of the key it fires briefly then I get a little gas cloud out of the intake. So far ive checked the coil for resistance, changed plug wires, plugs, cap, rotor, and crankshaft position sensor. I have on order a pickup for the distributor that ill try tommorrow but have a feeling that wont solve the problem either. May this be a fuel pressure problem? If so I gotta go thru the painful job of buying either a fuel pump or changing out the fuel pressure regulator being its also the fuel filter. Nontheless with almost a full tank. Any other ideas? Thanks.