Questions; Trying to learn /understand Nistune

[harukisan15]

Hi guys, I've got a real JDM 1989 S13 Ks model Silvia with the original CA18DET (about 77k original miles). My ECU numbers are 98, 23710-36F00 MEC- D003 E1. I've got a late 2015 type 1 board with Feature Pack. Just not to make it a long story of how I've gotten to this point with my Nistune adventure know that my tuner here in the USA has made some mistakes. I am now ready to go again to the tuner. Since the start there were some things to overcome information wise, like the proper ignition timing etc. JDM is 10deg BTDC and the EDM is 15deg BTDC,that misunderstanding alone has cost me hundreds of dollars in parts and labor.

Anyway, I have made changes from my basically stock CA18DET to swapping to a Z32 MAF and 680cc fuel injectors, I also have a T28bb turbo, Greddy hard pipes to & from the turbo, FMIC, 3" turbo back exhaust. I have installed a tune for these components and set up. Of course I know that this tune is just a base to get me to the tuner. Since the Maf and Injector change I am having a very unsteady idle, strangely after idling for about 30 - 45 minutes the idle will stabilize, I have heard things like "try increasing the TPmin and Target idle etc." What I haven't been able to find is how to exactly do thigs like this. Of course I understand while in the Consult mode to go to TPmin etc. but I see many cells and lines of cells that are I guess RPM and Value and I assume that it is the Value line that needs to be adjusted but I wonder things like How many Cells do I adjust and How to understand what numbers to put in these cells. I have been reading the helpful Nistune documents but it's not clicking in my mind what exactly to do. Maybe I'M over thinking these task but I do Not want to do things wrong and cause damages.

I would like to have this sorted out before I go to the tuner, If anyone out there can shed some light on this please do.

Thanks,

[Matt]

I have heard things like "try increasing the TPmin and Target idle etc." What I haven't been able to find is how to exactly do thigs like this.

Attached are the tables which are mentioned

Target idle (850rpm around 80 degC) when adjusted will make the ECU hunt higher/lower by adjusting timing/AAC to reach this RPM

TP min (TP) will adjust the minimum TP load in the ECU. Making this higher effectively can avoid stalling issues where the vehicle goes too lean. However you need a wideband for tuning to know what your mixtures are like to see if it is going lean or something else causing the idle issue.

You can adjust TP min values at the current RPM you are on, watch the TP and also the injection time (and resulting AFRs) to see if that resolves if it is indeed a leaning issue. When going off throttle, watch for the same also