Hey all, I'm trying to debug my 1990 S13 KA24E-T.

The general issue is a very rough idle (pretty much won't stay on unless I lightly press the gas from time to time). Also, it stalls if i press the gas quickly between 4-5k rpm

I have a Nistune Type 1 Board hooked up to it and have the following log replay:

https://www.youtube.com/watch?v=FCYXl0t ... e=youtu.be

This is a log of the selected sensors when starting the car and doing a slow rev (as can be seen by the yellow RPM line). The red line is the O2 sensor readings and that seems off to me, mostly because it seems inconsistent. Sometimes it fluctuates wildly (e.g. https://youtu.be/FCYXl0tbtB0?t=50) while other times it appears to start high and go low at a steady pace (e.g. https://youtu.be/FCYXl0tbtB0?t=24).

Main specs are KA24E, Z32 MAF, 550cc injectors, walbro 255 lph fuel pump

Could the O2 sensor have an effect on idle and rev?

Hmm, the factory service manual states, "This voltage signal is low (about .1 volt) when a lean mixture is present and high (1.0 volt) when a rich mixture is present." And the consult log definitely shows the o2 sensor hitting upwards of 2V