1994 Other Dodge Models hard to start

hi i have a 1994 dodge ram van 350 5.9 and the problem that im having is that whenever i start up cold the van starts up one crank but when it begin to getup to normal temperture or i try to take off the van shuts off and wont start anymore until its cool and its kicks over one crank.i have changed coolant temperture sensor,map sensor,ignition coil,plug wires,plugs,distributer cap and roter