O2 Closed loop (fuel trim unstable)

[tryskriel]

I have a 05 Mustang GT supercharged with a M90 Roush kit running 6psi with some BBK long tube headers
Running the 38lbs injectors from Roush

I did read the stock Roush program but it was always way too lean so i did enrich the MAF voltage table a lot.

It's almost finally tuned but for the part throttle tuning, the car will lose power when AFR goes in the 10:1 and 18:1 range and you can feel the car lose power. My fuel trim are not so bad, not perfect but within the 10% range. When i adjust them, at the same MAF Voltage, sometimes the fuel trim are positive and sometimes negative so i let them that way because they are always varying.

On others cars i have tune, the AFR is always stable, goes from 14:00 to 15:00 but on this car it seem to go from 12:40 to 18:00. Anyway of getting the closed loop system to work fine.

I did try to disable LTFT, play with OL Delay Ramp and blend ramp. I did try to run it always in OL setting all value in Fuel value TPS to ""0"" without succes.

Can i play with transport delay to adjust the way the CL will work ?

Thanks for any advice
Fred

[BlueStreak]

I have a 05 Mustang GT supercharged with a M90 Roush kit running 6psi with some BBK long tube headers
Running the 38lbs injectors from Roush

I did read the stock Roush program but it was always way too lean so i did enrich the MAF voltage table a lot.

It's almost finally tuned but for the part throttle tuning, the car will lose power when AFR goes in the 10:1 and 18:1 range and you can feel the car lose power. My fuel trim are not so bad, not perfect but within the 10% range. When i adjust them, at the same MAF Voltage, sometimes the fuel trim are positive and sometimes negative so i let them that way because they are always varying.

On others cars i have tune, the AFR is always stable, goes from 14:00 to 15:00 but on this car it seem to go from 12:40 to 18:00. Anyway of getting the closed loop system to work fine.

I did try to disable LTFT, play with OL Delay Ramp and blend ramp. I did try to run it always in OL setting all value in Fuel value TPS to ""0"" without succes.

Can i play with transport delay to adjust the way the CL will work ?

Thanks for any advice
Fred

i have the same problem with my na 07 gt. cruising, it goes anywhere from 11.6-16afr. and the fuel trims are never the same at a given voltage. i put a maf curve in my car last night, it as 13.0 across the board at wot. caLLING 12.8. I multiplied those voltages by 1.01625 and then it hit 11.8 afr. what gives? lol

[BlueStreak]

do you have 2.23? i tried to open your tune but it said unable to open. failed validation check.

[tryskriel]

Hi
No i have to run the 2.20 version because it don't make the validation check because i start this tune from the Roush file i did have in my ecu.
Do you want it ?

Fred

[BlueStreak]

oh i see. na. its not worth your trouble. i just try to look at every tune i can and compare differences. thats somewhat how i learn. there really isnt enough traffic on here to do it any other way. im still clueless as to why my car acts so retarded all the time.

[tryskriel]

When idling, the Closed loop work fine, it goes between 14.3 to 15.8 but when cruising, the AFR goes weird.

[BlueStreak]

I have the exact same problem. If I come across something I'll let ya know.

[tryskriel]

Yesterday, i did disable the MAF adaptation and it work a lot better but still have some issue, i will work more my fuel trim to see if i can do something better

What about the ETC calibration, i have read someone talk that you need to adjust that after the Maf table but i don't see how to calibrate that.

[BlueStreak]

Yesterday, i did disable the MAF adaptation and it work a lot better but still have some issue, i will work more my fuel trim to see if i can do something better

What about the ETC calibration, i have read someone talk that you need to adjust that after the Maf table but i don't see how to calibrate that.

where is this table? what is it called? ill do some research.