Hi guys. I recently bought an MS PNP gen 2 for 90 - 93 miata hoping to get better control of the idle and the AC.( I was previously using MS PNP gen 1. )

This is my miata's current set up:

'97 1.6L miata with a JR M45 SC, Innovate LC1 AFR, stock injectors, JR AFPR removed, AFM deleted and replaced with GM IAT, VTPS from an AT miata installed, Air valve deleted.

Before the install I added a board jumper for AC idle up connected to Table Switch.

So I got it installed, had the engine running, and the timing set to 10 deg.
Then went on to set VE tables and AFR tables. The new table generators were very helpful. I must say the engine type choices, peak power, torque settings were of great help. After setting that I ran the car and it ran great! ( No AC yet )

So when i got home I tried fine tuning idle with CL settings but couldnt get it to work well. I also tried the AC idle up feature but couldnt get it to work also.

I've searched idle settings on this forum and came across this:

https://www.miataturbo.net/megasquir...request-59027/ - Figured out my closed and open idle valve duty with this.

I've read Megasquirt 2 setting up 3.3 and TS reference guide. Tried to get as much as i can from it but the idle part of it is kinda hard to understand.
I also read on Greg G's thread with his DIY PNP as we have almost the same set up and i know him personally.

I also read that I should start with setting idle with open loop - warm up settings, set my timing/ign table first. But I'm not so sure where to start on setting it up.

So.. can anyone please help a noob set idle and set up AC idle feature. I've attached my msq and datalog.

Sorry for the long write up. Just wanted to give as much info as i can.

 

Can you enable Port Status in the Project Properties, and get a new log? This will let me see when the Table Switch input port is triggering in the log.

 

You won't be able to tune AC idle up until you get AC. It's pretty simple when you do though. You just mess with the valve opening and compressor delay until it smoothly idles up to your target AC idle every time you turn AC on.

Closed loop idle is a mystery that very few people understand. There are tons of threads on it. You just have to read until you think you get it, try and tune it and realize you don't get it, and repeat until you get something that resembles a smooth idle.

 

Thanks for the reply Matt. Here's a datalog and msq with the port status enabled in project properties.

Please take note that since my last post i've made a few changes to my settings as follows:

- on General Settings i've included AFR targets.
- i've reset idle control algorithm to open loop (warm up)
- rebinned ignition table and interpolated
- adjusted idle warm up duty cycle

I was able to get better idle with the above changes. Upon turning on AC, RPM still comes down to 650 and does not recover even with the AC control turned on.

 

Itty,

I have AC. What i meant there was that I drove the car without AC yet. Sorry for the confusion.

 

Hi again guys..

So since my last post these are the adjustments i've made:

- adjusted the ignition table where the car is idling to 15*, bumped up the 600 rpm row to 19*.

- adjusted AFR table idle bins to 14.3

- did a VE tune analyze

The idle seems to have gotten better with the setting changes above. It's stable at low 900 rpms. (open loop)

My question now is if these settings are good enought to proceed to cloosed loop idle tuning?

I've attached some pics of the basic settings and tables. KIndly point out if you notice any errors on it.

 

current tables

 

other settings

 

The question isn't what the settings look like - it's if you have a good, stable idle in open loop. If so, then you can try closed loop.