VR sensor Piggy back setup road blocks

Hello. I wired EMU black in a piggy back setup on a ford expedition 5.4L 1998 Twin turbo. I spliced into the positive signal wire of the VR sensors (Crankshaft and camshaft sensors) and connected each to EMU black.

I disconnected the fuel pump and hit the starter to check for trigger signal on EMU scope and found none.

When I disconnected the stock ECU connector I got a CRANK and CAM signal on the scope when I hit the starter which was weird since both signals were in the Primary trigger tab in the scope and I was confused on how the sensors were giving out a signal if their negative side was floating and not connected to any sensor ground.

Also I need to figure out why I can't get the sensors to work on EMU black with the stock ECU

Your help would be appreciated greatly as I've been stuck now for over a week

The VR sensor will still give a signal with the ground floating because the sensor generates its own AC voltage. Is there a software selectable pull up resistor turn on, because that would cause issues? Have you tried talking with ECU Master? They may have specific requirements for piggybacking sensors.