Why is my fuel map boonk?
 

hey guys, to start I have been trying to diagnose this issue for a few months now, i'm not getting correct fuel and my map looks like some spagetio's to compensate.
Does anyone have the slightest clue as to what could cause all this?
I have a:
Braineack style MS3X
JRSC (I hate it but it kinda works)
DW200 fuel pump
6 month old fuel filter
Stock FPR (its a new-used known working unit as of febuary)
GT500 injectors

Post a screenshot. If I have to open a file from the forum to comment, chances are I won't.

Post tune and log. Explain how you tuned it and why you think it is "boonk".

its a stock tune with the fuel corrections required to make it run, I used ve analyze live to get it workable. I have had a few actual tuners look at it and they have been unable to find a major error in the
tuning that would cause this issue but hopefully its just a dumb mistake.
I have rented a fuel pressure test kit, we will see how that goes tonight....

cmon people, turn on Incorporate AFR. This isn't the age of parallels and piggybacks. It is in the sticky.

So there is a lot going on in this log, it is pretty hard to extract useful information. The very last (presumably idle) tail is of interest.

Notice how you have ~2.1msec pw for an AFR of ~12.4.
The req-fuel is 4.5, the deadtime is essentially 0.63. negelt posted some pretty good looking data for 2 specific GT500 injectors, so assuming you have one of the two part numbers he listed, the config should be good.
So 2.1msec - 0.63msec = 1.47msec of flow time. 1.47msec * 12.4 AFR/14.7 stoich = 1.24 msec. 1.24msec * 30kpa/100kpa load = 4.13msec (hence the 100%+ idle VE). Idle VE should be around 50%, so you are delivering nearly HALF of the fuel the megasquirt thinks it is delivering.

But then at ~132s there are a couple of decent stable shots where the pw (~2.4msec) looks good. 60kpa/100kpa * 80%VE * 4.5msec + 0.63msec DT = 2.79msec.

This is the second time in not very many days where a member has had fueling issues in semi-sequential mode. I don't know if it is just a coincidence, or if it is related. The other install looked like it was firing at least twice as often as the MS thought, this one is half. The User Manual states that these settings aren't used unless in batch mode, but changing them recalculates Req-Fuel when in Semi-sequential, something is funky there.

• Squirts Per Engine Cycle - Only used when running batch fired injection. Determines the number of times per engine cycle (two revolutions on a four-stroke engine) injectors are squirted when in a batch injection mode. This setting has no effect when injecting sequentially.
• Injector Staging - This setting is used only in batch injection modes. It determines whether the two injection channels are squirted at the same time, or in an alternating fashion.

FIRST: Confirm that voltage at the injectors is the same as the voltage reported by the MS
SECOND: I suggest you turn sequential off and see if that puts you more in the 50%VE range at idle.

And for the love of all that is holy in the MS online support universe, turn on Incorporate AFR.

Why? I’m seriously curious why you think its that important

Because an autotuned and accurate VE table (as opposed to a fueling table) contains all sorts of useful information that is essentially lost (or at least hidden) when it is turned off. Sure I could open the tune, look at the target AFR table, do the calculation and apply it to the VE table, but seriously, I do this $hit because I want to help. And no offense to the OP, but in general you can't believe what any of these "My car is effed and I don't know what to do" posters say. I can trust that they will run the autotuner, and I can trust what the autotuner does. With a true VE table, you can tell if VICs is working, you can tell if VVT is working, you can see if they have characteristics of a blocked CAT, or too small exhaust in general. You can easily identify issues with Req Fuel, characteristics of a pooly set-up dead-time, or voltage measurement error. I can look at the VE table, and with my (limited) knowledge of the Miata engine, I can quickly and easily point out suspicious characteristics. WTF do I know if the poster targets 12.5 at 100kpa or 13.1. Idle AFR targets are all over the place, how do I know if an 80% there vs a 30% is correct because they manually tuned that area to get whatever they thought they should target.

Oh, and it has the added benefit of not needing to re-tune if you want to change the AFR map. That alone in my mind should be sufficient.

That "added benefit" is the only thing "incorporate afr" actually does.. As I'm sure you remember from that thread I made about sshamrocks tune, incorporate afr didn't help us diagnose anything so I'm just not seeing this insanely big benefit you're talking about.

Though I'm not disagreeing with you that in a properly set up and tuned car, it's definitely helpful.

Well to that, I guess I would say there is no silver bullet, and the community is lucky to have a couple willing contributors who use different methods and techniques to diagnose issues.

Oh I think what you (and a few others) are doing is fantastic and applaud y'all for all the help. People don't realize how helpful some of the regulars here are until they visit another forum where literally everyone is clueless and the answer is "ask your tuner". No matter the question

I see 2 potential things:

1) Too small dead time. This will cause the low kPa rows to increase VE relative to the rows above them. Try more like 1.2mS.
2) It just seems to me that you are not hitting the full range of cells. Thus, the ones you have hit during tuning seem to make sense, but the ones you have not hit, are still the original values. Check an old msg to see if that makes sense. If that is the case, 1st extrapolate (conservatively) the other cells. 2nd, make an effort to actually tune those cells. TS, or MLV cannot tune cells that have not been seen by them.

DNM

alright I was able to do the second fix you suggested. In batch fire mode the car ran very slightly more rich at certain points but overall seemed similar if anything it was a little more rough. I have included a datalog of the car going on a run with the new settings and Incorporated AFR. For the first fix where would i find the exact voltage my megasquirt believes its outputting?

also thank you all so much for the help this is really the best miata forum out!

I have had this issue even with stock injectors on a stock dead time, currently its set to niglets provided data with gt500 injectors. My original assumption was that it was a a mechanical issue such as my fpr going out again but i would like more confirmation that it is before I go and blow more money. This car still won't run on a stock basemap and that seems more like a mechanical issue to me but I don't know.

You have to retune the fuel map after turning incorporate on, I would hold off on that (despite the dump I took above) :)

the MS voltage is reported in Tunerstudio, if you don't have an indicator you can add one. Measure the voltage from the MS ground to the injector connector housing while it is plugged in and the car is running.

Oh, and after you turn incorporate back off, confirm that it still wants like 130 in the idle VE cells to hit your target afr. If it does, turn batch off and go back to sequential.