this happens all the time replaced head gaskets, fuel pump, fuel filter. any ideals
engine starts sometimes after its hot it will start for a couple of seconds then quit on 1998 Buick Skylark
Hope all that was not done to try and fix the problem. When dies need to check for no spark or no fuel to engine. If you did throw parts at this problem as per your list then let a qualified tech look at it. Would be cheaper than head gaskets.