i know you don't have any fuel at the rail and i'm guessing you don't hear the pump whine when you turn the key on but just for shits and giggles check to see if you have spark. i'm not worried about the ignition system being jacked i'm thinking the computer took a shit. why did you originally replace the ECU and how long ago was that? and obv if you haven't already check all the proper fuses including those for the ECU