Bodenham

I am getting and "Error 8" whenever I try to data log on my car. I can tune and download to the PCM, all seems healthy with communications that way, but as soon as I crank the car over or try to communicate with the engine running, I get errors. I have tried changing the grounding location for the 6AL box, but no help. This same thing happened whenever I tried with the stock motor with MSD as well as the new 383.

Again, MSA 6AL and Blaster Coil. 1995 LT1 in street rod. When all of the ignition was stock, I could communicate and data log fine. I'm looking for any solutions or insight.
Thanks

Bodenham

MSD 6A causing the error. unplug and go to stock, records just fine. Inerference? Runs just fine, MSD just messes up the datalogger