can't correct enough with IAT

[turbotankshane]

91 chevy s10, 92 b230ft, 16t, 0280155830 injectors, microsquirt running ms2 extra 3.4.2 code.

The problem I'm having now is temp related; I can dial everything in with no correction at 70 degrees ambient temp, then when it gets cold outside it runs extremely rich and I have to pull a LOT of fuel from the IAT correction table to get it to lean out enough. Similarly, its been very cold this last week so I tuned it from scratch with ambient temp at 34 degrees, then after it sits and IATs come up to 50-60 its so lean I have to dump all kinds of fuel in. This is after WUE and ASE are off, so the only correction is IAT.

I'm using a GM IAT sensor from the DIY website, in a small rubber hose off of what is normally the IAC port on the cold side piping.

I'm trying to get the msq posted, still a noob to this sub-forum.

I want to think that this would have to be related to injector dead time, but I get the same situation with dead time set anywhere from 0.850-0.950. Any suggestions?