Here is the original question with all the updates. ANY input is much appreciated.

https://honda-tech.com/zerothread?id=195357

 

I a similar problem with the Vafc on my R, but it just read differently with engine running vs. not running. it didnt jump around. I now have the unit installed in my HB civic, with the same engine and ecu, different wiring harness(civic ex) and no problems. the only difference then was the factory wiring harness. the vafc should get ground from the ecu harness and not chassis metal, but I'm sure apex'i would have asked you to check that already. good luck!!