Any workaround for VCM scanner stopping log at startup??

[Shaadyburbn]

After flashing new tune, engine will fire and run for a few seconds before dying. Trying to create a log to pass on to tuner in an attempt to see what's shutting us down, but it seems that VCM scanner stops the scan process at cranking when attempting to log from a static state. All basic fuel and voltage checks have been completed, definitely seems that something in the ECM is shutting us down. Some permanent emissions and Cam sensor DTCs present which have been disabled. When looking at the motor during the short run events with a scan tool, all systems look to be reading in correctly. Thanks in advance!

2010 Silverado LTZ L9H take out with original ECM transplanted into 2wd '72 Burb
Deleted with standard valvetrain upgrades(springs,trunions..)
Chevy performance stageII cam
LS3 intake and MAFs
Vette pedal
PSI harness
MOT tune
Reman 6L80 w/new TCM
What else?

[gtstorey]

Have you checked voltage while cranking?

[Shaadyburbn]

Yep, constant feed is direct at the starter and have confirmed+12v to ignition feed at all key positions save for ?off?.

[gtstorey]

Including while actually cranking?

[Shaadyburbn]

Correct. All key positions. Including cranking. Tapping the switched feed into constant has no effect (as per other troubleshooting on this matter) and voltage drops across all of the pertinent circuits have been exhaustively measured including all ground paths of individual components. I have stepped the supply voltage to all circuits up to 14.5 with < 1V drop measured during cranking as well.