More often than not from what I've seen this type of issue on a Vehicross has been solved by replacing the fuel pressure regulator. You could start off with an easier replacement project and change out the fuel filter first to see if that solves the problem though.
If you've ever gotten a bad batch of gas (watered down), the fuel filter would have captured that water and still have it inside. When there is water present in the fuel filter, fuel supply can become inconsistent.
Something else you could check would be the fuse/relay for the fuel pump. Similar symptoms used to occur on cars with mechanical fuel pumps because the diaphragms in those would develop a leak and they would not be able to supply adequate/consistent fuel pressure, but since we have an electric fuel pump, inconsistent power from a loose fuse/relay might cause similar symptoms.