Diyautotune built ms3x and a diy harness following trubokitty's guide. 99 miata stock besides ms3x and gm ait sensor. It seems like the IAC valve just is not working at all. Changing values in test mode does not change the rpms at all. When I made my adapter harness I checked every single wire with a multimeter so I really do not know what could be causing this. Car idled fine before ms3x so i do not think the valve is dead. Attached is my tune, maybe something is wrong on here. As of right now the fueling looks very very weird but that is the only way it has been able to idle with the non functioning iac valve.

 

You mentioned pulling your 99 basemap from TruboKitty, but the IAC Frequency is wrong. It should be set to 511, just like in his 99 MS3X Basemap. Might be why you had to go 70% duty at startup to see anything. I'd download a fresh copy of it and use the "Compare Tune" feature in TS to ensure only the changes you wanted are set.

 

i changed the iac frequency because i was hoping it would do anything. I had it set to 511 and even at 70% duty cycle it didnt do anything. I found that my alternator isnt charging my battery so im thinking things are not getting the right voltage and that may be my issue, not sure yet, gonna work on the alternator then fix the iac