poormxdad

Gents,

With a lot of help, the car seems to be fixed. https://www.miataturbo.net/engine-pe...p-91105/page6/ Thanks. I sent Nigel some beer money.

Now I need to tackle some things I haven't wanted to mess with. Since installing the lower mileage JDM bottom end and updating the base timing, an idle droop I had conquered is back. I know I need to go through the whole idle adjustment procedure but wanted to post my tune and ask if there's anything really heinous I need to change before running the idle adjustment procedures. I had planned to mess with her today, but we've got a steady, cold rain. We're having company for Christmas. No way I'll be released to the garage before Tuesday.

My plan is to follow the advise here https://www.miataturbo.net/megasquir...ed-help-90819/

and instructions here Mega Miata: Closed Loop Idle REV 2.2 (Will these work on MS3 Basic running firmware 1.2.0?)

I have three issues. First, if I rev the engine or move the car before the O2 sensor is providing an actual reading, the idle gets all wonky. I have to shut her down, restart and wait. I've learned to live with it, but sometimes, like making room for the next guy to get gas at the track, I'll move the car out of the way, shut her down...etc. Now that I know a little more about EGO Correction, it seems logical something would happen, but is there anything I can do? She has always done that since installing the MegaSquirt.

I'm seeing cold start, cold temp idle AFRs in the low 11s. When she warms up, I'm getting around 14.7. I think part of the reason is she's getting cold air from the left front wheel well rather than under hood air, coupled with the huge TSE radiator and 180 degree thermostat. Are my Warmup Enrichment and ASE settings okay?

If I start her when reasonably warm, say sitting in the sun in the parking lot on a cool day when I come out to go get lunch, even if I sit with her idling for a few minutes till the idle drops, the next time I push in the clutch the idle will shoot up to about 2000 for just a second or two, then ramp down.

Thanks and Merry Christmas,

DNMakinson

iTrader: (3)

I'm showing you are on 1.2.0. This has old idle parameters. Update to 1.4.1, the latest, stable release.

There is a discussion here: ms3-basic-firmware-update

It will be worth it to work with the latest stuff, especially as some of your issues are addressed.

I have attached my tune, which has good idle characteristics. Yours may not end up the same, but you can see what are preferred methods to use (MAT for the IAC Initial Values Table, rather than Use Last Value, which is why you are getting the action described in your last paragraph).

shuiend

iTrader: (24)

Yes I highly suggest getting updated to the 1.4.1 firmware. A ton of stuff has been improved since 1.2.0.

poormxdad

Gents,

When I'm doing the idle adjustment procedure, do I unhook the IAC while the engine is running, and do I reconnect it while the engine is running?

Thanks,

poormxdad

Sir,

Thanks much. Now that I seem to have 1.4.1 running, I plan to compare to your tune page by page.

Braineack

iTrader: (62)

????

ouch. when im home ill look at the tune, but jeez man...

no, that adversely rich during warm-up.

yikes.

DNMakinson

iTrader: (3)

I agree with Brain. This makes no sense. Reverant's instructions, IIRC, go through the IAC calibration procedure. The goal is to find the minimum value where idle drops, then the maximum value where idle increases. The goal is to only use % PWM that truly effect changes, and not try to use values below and above them. It is done in Open Loop, not disconnected.

You will need to post up your 1.4.1 MSQ for @Braineack to review, rather than have him waste time on the 1.2.X one.

poormxdad

See post #2 in this thread. https://www.miataturbo.net/megasquir...ed-help-90819/

The reason I ask is with the OEM ECU, you jump Pin 10 and GND with the engine running to do idle adjustments.

poormxdad

Here's my tune with 1.4.1. Something is very wrong. See post #134 in this thread https://www.miataturbo.net/engine-pe...7/#post1387176

poormxdad

Holy crap, my tune is very different. I'm not sure where to even start.

DNMakinson

iTrader: (3)

1) realize that your general tune is separate from idle, start and warm-up.
2) Since that set-up I have changed my idle PID to use slider only, no "advanced" P, I, or D settings. It is more solid. I also added more % up on the A/C, as that was set before I went to 10 degrees idle advance.
3) The thread you looked at re: setting idle is pretty good. Brain says to never touch the screw. I'd say, if you touch it, Curly's approach is good. You could also just put idle in open loop and command the valve closed, rather than pull the connector. I would also command the timing to 10*. In setting the 750 RPM, use the TS tach, not the one on the car.
4) After setting the screw, if you do so, while still warm, set the min and max on the PWM % for the idle valve. With timing commanded to 10*, idle in Open Loop, command less and less % until the idle stops falling (should go approximately to the 750 you set with the valve set to Zero). That value gets plugged into the Closed Loop Minimum. Then raise the % in steps. As you do so, RPM will climb. When it stops climbing, that is the % value you plug into the CL Maximum. Mine just kept climbing, so I think I just used the value that gave me 4K, as I figure the engine would never need more air than that.
5) Go back to Curly's warm-up and target setting procedure.
6) There is a wizard for setting warm-up enrichment that is pretty good. Remember to have EGO not operating during the procedure. I altered the method by not running in the idle area, but rather setting a target for idle at about 2000 RPM. That got me in a better place on the injectors for setting warm-up. For me, the warm-up curve is not just about idle, but about adding extra fuel in all of the operating areas. That philosophy has proven true in practice.
7) On start settings. I use a heavy priming pulse to wet the intake walls before cranking pulses start. Pretty sure Rev's base maps do as well. Others do not use that approach.
8) I personally like to Incorporate AFR in fueling equation. You do not. To each his own. If you change that, total update of VE will be required.
9) I have not had a chance to look at your tune. Perhaps tonight. However, again, as you will need to make lots of adjustments, I suggest you reset the basics and tune in a methodical manner. Fix MAT correction, zero out Baro, or set it for you altitude, etc before you start re-tuning. Then use VEAL.
10) Even though you tackle some areas one at a time. There is interaction, and so the loops will need repeating.
11) I use Idle VE and Idle Advance. That way, I can distinguish between running in that area vs idling in that area. the differences are minor, but this enables more advance as soon as TPS takes me out of CL Idle.
12) EDIT: And again, I'm not suggesting you use my exact settings, but more the concepts. Exact values are always build-specific.

poormxdad

I absolutely understand about the tune being build specific. Regardless, I need to figure out what's wrong first.

poormxdad

First question. Your tune uses "Two Independent Sensors" for baro correction. What's different about your sensors?

DNMakinson

iTrader: (3)

MAP is the internal MS3. Baro is the BP4W stock sensor repurposed from the EGR system. I have yet to tune Baro correction as I've not driven to altitude since wiring it in.

poormxdad

I live about 10 feet above sea level. The shop at had her tuned at is also about 10 feet above sea level. The highest elevation track I go to is Summit Point in WV at about 630 feet. VIR is at 500, and Dominion about 250. Set the Default baro to 100kpa?

Braineack

iTrader: (62)

yeah but on your tune, you have baro set to a static 60kPa. you need to look at logs, as you'll probably notice your gammae is not sitting at 100%, meaning you're artificially adding/subtracting fuel and tuning against that. I would turn this back on, set the limit to 95-105kPa and subtract a % of fuel across your fuel table. this is probably why youre fuel table looks so exaggeratedly high. we typically see VE table values around 60% at idle, not 90%.

you also have a MAT corrections table working against you. it's removing a lot of fuel when the AITs are warm and adding a **** ton when below 50°F. I would zero this out to 100% across and tune it last.

your injector deadtime and voltage % curve is probably the biggest reason youre having idle issue. i think it's set too aggressively. I bet if we look at idle logs we'll see the fuel actually cutting off completely.

using "last value" in idle control is probably the reason for the surge. I like to use initial values table for idle control and carefully tune that table.

your AE values would be better if you tuned accel-pump over the time-based. its the difference between code written in early 2000 vs 2011.

poormxdad

I hope this isn't a stupid question but... if Baro Correction was Off when it was tuned, what difference does it make what default value is in there? There are a lot of other things that are "Off" that have crazy values greyed out.

I'm at work and need to digest the rest of your post at home rather than on my phone.

Thanks much,

Braineack

iTrader: (62)

look at your baro corrections, it's subtracting a % of fuel across the board. you basically tuned around it, basically your fuel table is a % higher across to make up for it.

DNMakinson

iTrader: (3)

This is what I've been trying to say. https://www.miataturbo.net/engine-pe...p-91105/page4/ post 111.
Update FW, zero out the crazy stuff, tune in an organized manner.

poormxdad

Does that mean all the other greyed out default values are being used even if the parameters are off?