I have a 1999 dodge ram 1500 truck conversion van

I have a dodge ram 1500 truck conversion van. the van ran out of gas and everysince then the van has been stalling. i have consulted 4 different stores as well as the manuel and have gotten 5 different answers. please help. it will crank sometimes and other times it will not crank. please help
it happened a few days ago. some have said that it is the fuel pump others the fuel filter. now the problem is coming as to whether there are one or two of the pumps and filters on the van. the manual is showing one by the engine and one by the front right tire. i don't know where it is or if this is even the problem.
when it first happened, the van had to be pushed home. it would not start. we got gas and put it in the tank only to have the same problem of not cranking. next day it turned over and (even when in park revving the engine, in drive, and in reverse) it would work ok. a few hours later it went to stalling during these three gears. the next day it was still stalling. so it has been touch and go with the stalling.