Hondata

Problem solved! The temperature range on my water temperature compensation parameters only went up to 65 degrees C.
I'm not sure why this suddenly happened but I restored air and water temp compensation defaults and the problem is gone.

Replaced the thermostat with a new OEM unit and replaced the alternator, voltage is better now.
As before, when car is warming up as soon as my ECT climbs to around the 150 degree range (plus or minus a few degrees) While datalogging I can watch the ECT.c go from zero to -39% and the car idles ...

I must have a weak alternator as I just installed a new battery, I will change my alternator and see.
A new thermostat wouldn't hurt as it has been 5 years since I built the engine. I will try these and see where it gets me.

any thoughts about the temperature compensation pulling too much fuel out ...

Setup:
I am running a P28 Ecu with S300, Car is a 1991 Civic, my engine is a B16A with an OBD0 - OBD1 Conversion, it is turbocharged, I am using all factory sensors except for a honda OBD1, 4 wire O2 sensor and a GM 3bar map sensor. The engine is fully built, now at 9:1 compression, and was dyno ...