first thing is to check your ECU for error codes (search for it ). It definately sounds like a fuel problem and could be the fuel pressure, filter or possibly the injectors. The VG30 will run on 3 cylinders if you let it (not well but it will) so the chance of 3 or more injectors going out at the same time is unlikely.
how'd it run before you put the gumup in it? Any chance you used th wrong stuff for the wrong application?
Have you checked your MAF? You can pop the hood, have someone start it and you can wiggle the wire/connector on the MAF to see if it makes a difference.
If it runs rough always as opposed to running ok for a little the dying, maybe it's the timing.
There are a few things to check but first is the ECU.
Keep us posted as to what you find and we can continue the diagnostics and hopefully help others who may have similar issues