first u prefill both your fuel filters and install them. The vehicle may pick up the fuel when u use either again, maybe not.
second, if you have a fuel bulb, you can check at that point to make sure u are getting fuel to that point.
third, there is always the electric fuel pump. I carry one with hoses attached n wiring in one compartment ....
fourth, One bus I had a fuel problem with had a piece of cardboard stuck in the bulkhead fuel connector in front of the engine... so it can be a blockage problem
you can also check at injectors of course
Jesus Christ... Conversion in progress.