1996 Chevy Blazer no fire no fuel

okay 1996 chevy blazer 4.3 4wd has no fire no fuel. we can use the bypass and fuel pump works but no fire still. drove it saturday parked sunday battery was dead replaced it and no fuel or fire what would cause this? we did check everything with voltage testers and test lights we have power at the fuses. we used a fuel pressure gauge and just cranking the engine no pressure but when we hook up the bypass we do have pressure.