Cold weather start

[Broscheslide]

So I’m having this issue when the weather gets below 40 degree f. Car will crank and start but it will idle low. It doesn’t die but after 10 seconds it’ll smooth out and idle at my target. I should mention that if I do give it gas within the first ten seconds and let off the idle will jump back down and struggle. Idk what my afrs are at because the wideband is in heating mode. I’m assuming it’s rich because when the afr begins to read itll be at 10:1. Do I go to the fuel compensation at those temperatures and subtract or add fuel till it starts without a hiccup?

[Spunkster]

You should turn the key to the on position until the o2 heater has heated the sensor properly then start it and see what the AF reading is when this happens.

[Broscheslide]

Ok. I wasn’t sure if it was ok to warm up the sensor. I had a mtx-l and it warranted to not let sensor warm up before starting. Switched to a x series

[Broscheslide]

Ok on cold start it was reporting 10.1:1 and after 20 seconds it would be at 12.1:1. Afr target for lambda was 13afr at 30 degrees. Ect compensation was at 18 percent. Gonna lower the ect compensation fuel and see if it improves.
Also I have a question regarding battery voltage. My Hondata reports 13.1 but will fluctuate rapidly to 12.4 bolts and then back to 13.4. Repeats very quickly. Is the battery voltage at ecu supposed to be stable? I noticed with this fluctuation my idle will have this rhythm that seems to correspond to this battery fluctuation. Or it’s just my ocd

[Spunkster]

It should be stable and not fluctuating rapidly.

[Broscheslide]

Anything I should look at in terms of this voltage fluctuations?

[Spunkster]

What vehicle is this in and what modifications have been done to it?

[Broscheslide]

D15b2 1990 civic std
Mpfi conversion
Td04 turbo
S300v2
390cc injectors with resistor box
Obd0 to obd1 jumper
Intercooler
Z6 intake manifold
Skunk 2 half rad
Mishimoto slim fan
Aem x series wideband

[Spunkster]

Post the calibration used as well as a datalog showing a cold start and, one showing a hot start.