[Lambda is not view]

Looks like first one when displayed correctly is lambda 1 and when not displayed correctly it is Lambda avg.

 

[S52 E34 OBD1 Not getting any trigger signal]

Did you get this figured out? I am running a G4x on an E34 with a M50B30 non TU. I am using a wiring harness form a 95 E34 and the ECU plugged right in an fired up once I got the Cam trigger set up right. I am using the Hall cam sensor but the NonTU trigger wheel so that took a second to figure out. Also using the 60-2 crank trigger(balancer) from the TU engine. As long as you are using the hall cam sensor and vr crank sensor it should work.

Those are wiring diagrams for a 95 E34 M50Tu with DME 3.3. The other wiring you were told to swap was for the older 3.1 NON TU DME wiring harness which has a VR cam and VR crank sensor. Don't do it as you have a 413 DME so your harness is wired correctly to just PNP.