what are you looking at for engine temp
is it the ecu coolant sensor with a scanmaster or other scan tool, or an aftermarket gauge which uses a different sender?
if the ecu sees below 140 depending on chip you could fall into the warm up mode because it isnt up to operating temp yet, the timing wont be full and the fueling will be under slight enrichment and will be under open loop (wont go closed loop below 140) but at 140 it should be considered at op temp idle and fueling should be normal
i have to ask
why did you post this in an alcohol forum?