Hello,

I posted about this on my build thread but didn't get any traction. I've watched all of OGpedXing's videos on tuning and feel like I might be missing something (intelligence wise) because I keep racking my brain about this and I'm getting nowhere.

Car is a 2002 Miata (NB2/VVT), GM IAT sensor, AEM UEGO, stock exhaust manifold and ISR Performance Exhaust.

For starters, AC doesn't work at all anymore. The output that used to control it is Injector J if I remember correctly, but I get this weird error with VSS and don't remember what the correct input is either. I think some of my issues with starting the car stem from me basically killing the battery from trying to tune the car all afternoon until 10PM, so it's on a battery tender now.



Secondly, no matter what I change the values to in my Initial VE table it idle hunts. I saw that EGO was at 85%, so I tried to take some fuel out and it just starts hunting around. Part of it could be my initial throttle value, but I messed with it all day and got nowhere.
The main issue that I've been facing is this idle hunting, idle drops (gets rich), then increases (gets lean) over and over again. One weird thing is without my foot on the accelerator, touching the clutch changes the idle and sets off the hunting. I can stop it with a little tap of the foot, but obviously this is wrong.

I've gone ahead and attached my tune and logs(I think one log is the idling, and the other is some big idle hunting when I depress the clutch). So far I personally feel like I've made a ton of progress since the car actually drives, but I feel like it's obvious that I can smooth it out and fix it I could just use some more guidance. I also *attempted* autotuning and failed miserably on the idle VE, but feel like I made some(?) progress with at least learning how things work with the full VE. I know it's probably extremely sloppy though.

Also, the CLT was because I forgot to set up the secondary fan. I did that and the temps are fixed.




Sorry if any of my questions seem dumb, I genuinely am trying to learn and get everything together. I definitely shouldn't have done this on a two-day weekend (the car is supposed to be my daily), so I'm genuinely losing my sh*t.

 

I can look through your logs later, but make sure your inputs and outputs are setup correctly.
Manual here: https://www.ampefi.com/support/pro-mm0105-miata/

Set the cooling fans through the fan menu instead of the advanced outputs



As far as idle tuning in general, make sure the engine states are set well and that the ECU is staying in closed-loop mode. Especially when the AC engages, the higher load can bump you out of closed-loop so set a higher allowance, like 15-20%. Personally I haven’t found a low value necessary there. I also found that Idle-VE causes more issues than it solves, so I recommend turn it off and tuning the main VE table. Lastly, large swings in AFRs will make the idle unhappy. Tune adjacent cells together to start and make it stable first. Set EGO correction very low at first so it doesn’t affect your results too much.

 

Ah, and another thing. My experience with TunerStudio on a Mac is very very bad. I had it corrupt the MSQ once, and add very odd settings randomly more than once. YMMV, but I strongly suggest a cheap PC or at least virtual box

 

Had a chance to look through your MSQ and log. The main issues I see that would be causing a problem are:

- Enhanced Acceleration Enrichment is enabled. Turn it off until you're done tuning. This affects fueling in a major way
- Inputs and Outputs misconfigured. Use the picture and manual above to fix those. AC request is set to clutch input, and AC output is not set to an documented pin. This explains why pressing the clutch is doing weird stuff.
- Your idle initial values are too low. You engine seems to want around 30 to idle at 850 RPM, explains some of the stalling.
- Use higher ignition advance at idle. Around 15 and let the closed-loop change the ignition more
- In fuel cut, you should set the Highest RPM to Re-Engage fuel higher than the Lowest RPM, 1800 would be fine.
- Turn off Auto-zero TPS and re-calibrate your TPS sensor

 

Thanks to both of you for the response! I ended up just restarting again today and everything seems to work reasonably well now, at least when it's warmed up... I'll have to confirm cold starts later, but I don't see why it wouldn't work. The fans both work properly, the TPS is calibrated properly, the AC works and doesn't seem to do anything weird again. I'll go back and change the idle initial values, I think they're in the mid-high 20s right now. Fuel cut looks like it's working as well.

It's currently still using Idle VE, but I can move those values into the main table and turn it off.

I'll also go back in and use a higher ignition advance like you said. After this I'll just continue to make revisions since I know that it's pretty rich, but I just needed the car running and moving until at least the weekend. This also gives me somewhere I can go back to in case I do something dumb.

Editing to say that it cold starts fine and I have been gradually making some changes to the tune but probably won't implement them until tomorrow just to be safe. It's definitely rich overall but I don't want to change anything with the table until I turn off Accel Enrich.

2025-04-29_15.22.00.mlg
WORKINGTUNE-2025-04-29_15.37.15.msq

 

2025-05-01_06.13.55.mlg
2025-05-01_13.47.33.msq

Been working on this for the past few days. I think I'm at the point where I just need to smooth out the VE table a bit and keep working on the idle. After that I'll look to implement EAE. I still have a few cells that are on the leaner side but I'll probably go for a drive with VEAL and add a filter for AFR. Wanted to say thanks again for all the help, I think I just needed some time to learn from practice. I was so scared that I might nuke the motor lol.