cowboys647

So I don't know if I'm missing something but I think I have my charging system finally working but my idle won't stay stable and the car stalls with good afr's. If I keep it really rich it'll run though. Do I have something mixed up?

hornetball

iTrader: (4)

Look here starting around post #11 for a decent idle tuning procedure:

https://www.miataturbo.net/megasquirt-18/timing-idle-requesting-some-help-57133/

cowboys647

On 1a you say change the minimum and maximum duty cycle to 19. Do you mean in the pwm idle duty cycle in the right column? My kpa is solid at 30 and my rpm is set nicely at 950. The only problem is I can't get a solid Africa. If I keep it at 12.5 or less its perfectly smooth but any more and it just gets real rough?

hornetball

iTrader: (4)

That procedure was specifically for an MS-1 and an older 1.6. The concepts are applicable to what your are doing although your idle duty cycles should be much lower. The point of the procedure is to remove variability so that you setup one item at a time. A fixed duty cycle (pwm idle duty cycle) allows you to set your VE for maximum vacuum without interference from a variable air leak.

For idle, it really is better to set your fuel with vacuum than to target an arbitrary AFR. If you want to target AFR then: 1. Make sure your AFR gauge is accurate; and 2. Slightly richer than stoichiometric is what you shoot for (something like 12.5 to 13.5:1).

Looking at your log file, it doesn't look like your AFR signal is reliable. I see excursions up to around 20:1 with all other parameters looking pretty normal. This can't be real. One thing to consider is whether the sensor's heater element is functioning correctly. At idle, supplemental heat is usually required to get a good reading out of these things. You might also look for wiring/grounding issues.

cowboys647

Oh ok I gotcha. It seems like it works right but then again I don't have anything to compare it to. Thanks for the help

Techsalvager

what fuel injectors?

cowboys647

rx7 460's

Braineack

iTrader: (62)

Post log. Id reccomend the latest gslender firmware. Tuning idle iis easy but takes a few mminute worth of time invesment to tune the parameteres correctly

rb26dett

If your charging system has affected your idle significantly, I'd look to your injector dead time settings, they're likely wrong.

rb26dett

Though, having said that, it's actually *not* possible to have them correct in MS2 (or ms1), however you can get close enough for it to be ok most of the time.

cowboys647

I've never messed with my dead times actually. Guessed I missed those. Its weird at idle it surges a lot and starts slowly going lean until it dies. Not sure if its charging related or what not. Ve table is steady throughout idle area, timing is good, and afr's start out good. I had a dyno appointment the other day at begi but for some reason my car stopped charging. Now that it is running (poorly) I may try and limp it down there so they can do their magic.

Techsalvager

need a log of when it happens, a long log.

cowboys647

Just went out to get a log and I think somethings draining my battery while the car is off. I fully charged it last night...

Braineack

iTrader: (62)

What does the battery voltage on your above log look like? Should be solid around 14.2v