Idle rev hang
 

97 Miata with MS3PNPPRO, 640cc injectors, MKturbo kit.

I have it idling really well using closed loop idle and have read a ton on this site to get it right. The only issue I have is that if I blip the throttle in neutral or when shifting to neutral to come to stop light, the idle will come down to about 1200 and then hang there for a few seconds and then will drop down to the 850-900 where its supposed to be. I have tried adjusting the closed loop idle settings while sitting in the garage and seeing if it makes a difference, but nothing does. Its not a terrible problem, I am just trying to find out why its doing that.

Has anyone else had this issue or know what I could try to fix it? I have attached my current tune if anyone has time to look at the settings. I mainly am using the settings that are on the base map from trubokitty.com. I am also having a crap load of problems trying to set closed loop boost control, but that will be for a different time.

Log?

You will want to tune your closed loop idle initial value table a bit more, I had a rev hang issue and ended up fixing it by changing the max RPM X axis value to 1100 from 1200, and lowering the values in that region to the proper value at the RPM you want. Tunerstudio seems to reference the highest RPM value when entering closed loop idle, and as your 1100 and 1300 region are all 34.1 IAC% duty your car is probably just hanging around there as that is what it is being told to do.

Here is my tune, see my closed loop idle initial value table for an idea on how to distribute the IAC% value when the Y axis is scaled by coolant temp.

The lower your top right IAC% value is, the lower your RPM when your car enters closed loop idle.

Thanks man. Ill give that a shot

That fixed it! Thanks again