I am recently having the exact same issues as Baldwin describes here. I was wondering if you ever figured out or resolved this issue. Any guidance or additional info is greatly appreciated.
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.
You absolutely must check (or just replace) the FPR and the vacuum line to the FPR from the port back behind the engine. This vacuum line is kind of hidden and is subjected to a lot of heat that make it fracture and fail - If this line doesn't hold vacuum to the FPR, it will cause the exact problem you are having. Good Luck.