[PSIG]

It's disheartening to re-read these frustrations. The issue with code fixes, is that the ECM needs to act before the load occurs. That means controlling the load (not reacting late to it), delaying the load, and engaging idle-up not too soon or too late. That is a large burden on the code and TS configuration to ask. But, it's OK you asked.

It is possible to "idle-up" these loads instantly with Idle Timing, and why it was suggested. Yes, reactive, but very quick. To idle-up with IAC is very slow, and requires that load control (ECM must control the function, e.g., AC) with yet more code load. While I have not tried it for these issues on an MX-5, the AuxIO may be configured for some of these, I.e., sensing power for AC clutch /fan/whatever, activating more air, waiting 1.6 seconds and then operating a load relay to engage the AC clutch or other thing.

If Idle Timing does not do enough somehow, and the basic tune is truly solid (all settings, especially "little" stuff like injector voltage corrections, dead-time, coil dwell corrections, idle VE scaling, tuned O2 settings, etc), then I'd take a shot at AuxIO as easier and quicker to try before modding code. I hope you understand that the issues indicate settings or tuning weakness, and stability should be good (no worse than a carb), so features should not be required. I'm sorry, but there is no way an MX-5 at 1300 stalls with AC-on if the tune is good. That is the help we were offering. If that's not working for you, I hope these other options get you what you are after, quicker.

As I have suggested many times before, modding Speeduino is not the only option, and idle-up does not have to be part of it. An alternative to modding Speeduino is a simple standalone board for these and many other extra functions. While you could brew your own with a $3 Nano, @dazq's GPIO versions are made for just this kind of stuff, and with high capacity for lots of busy work. If it will operate an auto transmission, it will increase your idle. Check out the tech: GPIO for Speeduino

[nm145]

PSIG, I have read a lot of your posts and I know you are a master with speeduino. I feel that I have done everything to make this work. I don't have a normal situation. The little 1.8 idling at ~800 rpm just can't recover from the start up load of the 2 fans that I am running. The car is an open frame with no cowling so the fans need to be oversized to keep the car cool in the 100+ temps in the summer where I live. BTW the miata motor has horrible cooling on top of it.

The car had multiple slots on the dyno for tuning as well as some street tuning. This is by someone that knows Miatas and has tuned may miatas with speeduino. The IACV on the Miata is slow to react so idle advance was the plan. The draw of the fans at start is just too much and between the voltage drop and the alternator reluctance the car won't stay running. We did a test with one fan and no problem. But the initial draw to start the two fans is just too much.

In the idle areas of my VE table and the areas around are good.

There is a timing trough so there is a fair amount of timing to advance with idle advance to try to idle up with timing. There has been a many different timing scenarios tried to see if we can get it.

I have aftermarket injectors that provided a voltage correction chart and dead time settings that were spot on. I did some trial and error on the lower voltage corrections to see if it will help with the recovery and there was no positive effects.

I have questioned the tuner multiple times about the dwell correction and he swears they are good and not the issue.

This is not something that was a quick decision. There was a ton of effort to get to this point. The car runs fantastically and for that the whole speeduino project (to which I know you are a big contributor to) deserves a big high five. It just won't stay running when the fans are triggered. You are not near the car so I know you can easily chalk it up to a bad tune, but that is not the case.

You mentioned stalling at 1300. The motor idles between 800 and 900 and stalls way before idling up 1300. If I set the idle to 1100 or higher there is no problem, but that is much too high of an idle for me.

As a test case, tonight I threw together a nano project that takes the fan output, sends idle up back to speeduino waits 1 second, then turns on the fans. Works great, I just don't like having something as important as the fans being controlled by a nano. It is just another point of failure.

I am new here and I am asking this nicely so please don't take this the wrong way. I have been a programmer for over 25 years and I have been a major contributor to two large open source projects. Isn't this what open source is all about? If a project is not exactly what you want, fork it and make it so. Yes, maybe adding idle ups may add some overhead, but this was for my special case, not something I was asking to be added to the project. I can figure it out myself, but I figured if Hugo already did it, it would give me a head start. And yes, I can add more modules, but that is just more points of failure and I have a space the size of a shoebox to house every module in the car.

Thanks for the reply, it will push me to go over the tune another time and see if I can get the stupid car to stay running.