I would also check your grounds and make sure they are tight and have a good earth first, then I would then look at the fuel pump relay. Maybe check to make sure the ECU harnesses are securely plugged into the ECU, and if you remove them, check for corrosion at the contacts, although I don't think this is the cause. Also the bank angle sensor has a connection to the fuel pump relay and will cut it off if it senses a tip over. This could have failed, or the connection may be loose.
I have attached a link to the wiring diagram for your reference.
http://www.rc51.info/RC-51/namshub/V...g_diagram1.pdf