Cranks, no start

Car drove fine, parked it and was gone 3 1/2 weeks on vacation. Come back and it cranks but will not start. Checked all fuses and even changed out main relay just because. No fuel on rail and no spark. Fuel pump works fine. Changed crankshaft position sensor. Still nothing. Reset security system 2 different ways. Still nothing. Car is fully charged. No idea what else can be done. Please help.