I had the vacuum pump turned on, and I thought about hooking up the vacuum/boost gauge (I just have the port capped at the moment) to check it out, but decided I'd wait until I was happy with the running of the engine (aka run above 1,200rpm). I'm 90% sure it's the signal filter adjustment.
_________________________
Rebuilding an OHC Pontiac 250 with EFI and a Turbo