Turbo2004

Basic run down on my nb miata with adaptronic ecu
Built motor stock cams Non vvt motor but with flat top manifold
bosch 1000cc injectors
Aem fuel reg not boost referenced
Walbro 255 stock fuel pump wiring
duel feed fuel rail reg mounted up front just before rails


Problem is my fuel map looks like crap. Even before on old engine setup down low around 2500 / 3000 rpm it has that spot were it needs crap load of fuel as you can see.
Also around 3250 rpm on boost needs big dump of fuel then goes lean and kinda then richens out by what the ve map looks like , but tail pipe sniffing with wideband shows it hovering around 11.8 12.0 af ratio when on boost ?

At that point with wideband out back the wideband is showing around 11.8 12.0 af ratio on pump 93 fuel.

Any ideas of what it could be?
Timing is kind of flat and there is no crazy jumps in timing were the 2 weird fuel ve map parts are that im referring to
Fuel reg holds around 58 psi or so even on full boost to redline and i dont think im no were near maxing out the walbro 255 on pump fuel and non boost referenced fuel reg

sixshooter

iTrader: (12)

You really need to run a boost referenced fuel pressure at 22psi. Your 58 at the rail drops to only a 36 pound difference in boost and is likely hurting your fuel atomization some. At least get it up to 43 or 44 where the injectors are designed to operate.

I'm unfamiliar with tuning Adaptronic but you are correct in that fueling map appearing odd. Does it autotune for fueling?

A misfire will register lean on an O2 sensor.

Turbo2004

Only reason i didnt boost reference this setup is because by what ive seen the walbro 255 falls on its *** when boost referenced say trying to run 80 psi of pressure.

No auto tune.
Setup on dyno
Car is running ls3 coils and msd leads. All leads checked ok. Coils are brand new of a crate motor.
Spark plugs are brand new also. So was no misfire.

Even down low at 2500 -3000 rpm you can see i have to richen up the ve table just to get it decent a/f ratio happening. Thats just at cruise were there is no boost.
Have tried 2 wide bands on the car and the dyno one so no problem there also.

Turbomack

What HP target do you have? We had fuel pressure/feed irregularities on the dyno as we got into the 300’s. First had WB255, then a DW300 and the issues went away with the Aeromotive 340. Setup is 80 micron + 6 micron filters, -6AN feed line, dual feed rail, ID1050x, Fuelab FPR boost referenced, and stock return line.

Turbo2004

Turbomack looking at 300+ whp between 300 -350whp
Ive used walbro 255 on other cars before and it can make 400whp on ls swap v8s etc.

Im using walbro 255 (on stock wiring) feeding factory fuel filter (which is not that old)
feeding fuel reg aem brand
fuel reg splits of to 2 lines that supply the fuel rail.
Return line comes of the reg through to stock size steel return line that runs back to miata gas tank.

Have a set of id 725 i could try out on the car just did not use them as i was worried they maybe 2 small for my power level.

Turbomack

A V8 swap would have the same 255 pump operating on a different point of the flow/pressure curve. Walbro has those curves on their website. Higher the back-pressure (i.e. operating pressure), the lower the flow you get. If those flow and pressure points aren’t matching up to the injectors as sixshooter commented on, irregularities will ensue. Also, the smaller your feed line from pump to rail, the more headloss you have and like the curve shows, lower flow. None of this is to say that your problem isn’t elsewhere. 725’s should be fine for the power levels you have but E85 setups obviously require more flow than the 93 pump gas.

EDIT: Walbro Fuel Pump Curves Link
https://walbrofuelpumps.com/fuel-pumps-pressure-charts

Turbo2004

Turbomack i under stand were your coming from.
Just weird exp down low when not in boost how the ve map can jump 10% from one cell to the next just to try keep the air fuel ratio in track were it should be.

Have had another shop from near me say he will not tune any adaptronic cars anymore as the software is broken and he always gets a lot of headaches like this when tuning them