I'll throw another cast here but when I've messed with anything electrical on my Calais I have to reset things thru the immob or I get sh*t.I have to close all the doors, bonnet & boot then press reset or nothing(stereo incl)& it'll keep beeping like a smoke alarm.Dunno if it's just my immob or they all do it.The fuel lines are under extreme pressure in the EFI's & need bleeding from memory if you run out of fuel or in your case changing the fuel pump.That's why they run the big solid metal filters under the arse because the pressure would burst the plastic types.When I turn on the ignition I can hear a quick buzz from the fuel pump as it immidiately pressurises, especially in her EFI Berlina.Sorry for raving the obvious if you knew that already.As for a wiring issue I'm not much good there, I could help you to rewire it to pre-ignite with my wiring skills.I lack the experience, old age perhaps, a complete idiot maybe, or all of the above...I have all 3 variants of the black motor here & they've all been very naughty at one stage or another..