Sounds like your injectors are stuck open. Usually fixed by pulling it over with WOT a few times, can do with plugs in or out, with TSS disconnected this may not work. If doesn't work, try disconnecting or clamping off the fuel line and then pull it over 10 or so times before unclamping and letting it fire. Frustrating as hell but should be fixable. Best of luck
There's a quick connect in the line leading to the rail. Are there check valves in this or is gravity fed fuel from the tank going to squirt out everywhere if I pull it apart?