did you replace the fuel pump?
the one that is in there is almost 20 years old. It most likely isn't putting out the pressure it should. It might be pumping gas, but not at a high enough pressure. If you haven't, then get on ebay and buy a walboro for 90 ish bucks. swap the pumps out and try again.
it won't throw a code for not enough gas... kinda wish it did, it would help to avoid all of that mess you've gone through thus far, but it doesn't
Try that out and post up the results...