Ltft

[Gelf VXR]

Do they still apply in Speed Density?? Or only to Closed loop


Can LTFT numbers be programmed into the PCM?

I ask as if yes to both, the LTFT's can be used to offset the difference in fueling between the two banks BENs results... as it does in normal closed loop operation.

[ssvolvo]

Fuel trims are the percentage that the ecm is adjusting injector pulse width rich or lean from stoichic. As the switching point of a narrow band O2 is 450mv then we are working with 14.65? to 1. I don't believe this number is able to be changed with E40. Obviously your O2 sensors must be enabled.
In tables B1511,B1512 one can adjust how far off stoichic the ecm will compensate from base. Maybe easier said how far off of your map.

Gelf, You've helped me big time with your tutorials. What are we thinking of doing?

Can one disable the MAF and run fuel trims off the MAP only? I don't see why not. Can one compensate bank to bank? I don't think so.

John

[Gelf VXR]

Fuel trims are the percentage that the ecm is adjusting injector pulse width rich or lean from stoichic. As the switching point of a narrow band O2 is 450mv then we are working with 14.65? to 1. I don't believe this number is able to be changed with E40. Obviously your O2 sensors must be enabled.
In tables B1511,B1512 one can adjust how far off stoichic the ecm will compensate from base. Maybe easier said how far off of your map.

Gelf, You've helped me big time with your tutorials. What are we thinking of doing?

Can one disable the MAF and run fuel trims off the MAP only? I don't see why not. Can one compensate bank to bank? I don't think so.

John


Mmmm, if i remember correctly the LTFT's are independant for each bank?

LTFT affect the PE fueling, adding but not subtracing??

I was thinking that if the LTFT's comensate the OL fueling, you might be able to program the LTFT's to add fuel to the leaner bank??

[ssvolvo]

Gelf,

Is your tune so spot on that you can define what is needed bank to bank? I don't trust my wide band to be that close. After all that's why fuel trims are utilized. I have always been under the impression that once in open loop fuel trims go out the window.

I have a terrible time trying to log and actually see fueling changes with pe mode B3618. Have had much more success with BO148.:doh2: