2006 GTO Fuel Trims

[Cooter]

I just installed my trinity with the Diablo tune. What fuel trims should I see? I am getting some high numbers (+10) range.

[06MonteSS]

what mods are done to the vehicle??

[Cooter]

No performance mods. Doesn't read any negative values while driving in monitor mode. 0 is the lowest value. 10 - 11 are the highest values. I see these higher numbers sitting at idle with the car warmed up. It will read .78 on both banks and after a few revs it will idle back to 10 from the previous lower values. When just driving it ranges from a low of 0 to a high of around 6 - 8.

Does the unit report neg values in monitor mode?

[06MonteSS]

yes it does... but apparently you're not running rich, so the ecm doesn't need to subtract fuel, so that's why you don't see any negative values...

while steady driving on the highway with your rpms around 1800, if your fuel trims are +6 to +8, then it's on the lean side, and the ecm is adding that percentage of fuel...

so, modify the tune and adjust your injector slope to -5%, then reinstall the tune...

and that's that...


or for even more performance gains, like even better throttle response, acceleration, stronger/harder pull, etc... you could get a custom tune done for it....

[Cooter]

You are going to do my custom tune after I install my longtubes. I made that deciision before I bought the unit. Just too cold out right now to lay on my back in the driveway for 4 hrs. What should I be seeing at 1800 rpms constant? Sould I do some logging before I change anything? Just installed the unit today.

BTW I did notice a nice power increase immediately. Just playing with it now.

[06MonteSS]

hahaha.. ok, cool...

ok, when doing logging or just monitoring, select the DS_LOG_REDUX gauge layout... that has the necessary parameters in it...

and you want to cruise on the highway at around 1800 rpms... and see what the ltft's are reading.. BUT, it's cold weather right now, so they will be more positive than if it were summer time temps... so when adjusting your injector slope, I would not go any more than -5%...

cuz come summer weather, that's when we'll want to re-check 'em to make sure they're in the 0 to -2 range...

[Cooter]

OK. I will do that. At 1800 rpms and say 35 degrees what is a good number? If it is range I will not adjust anything as I am still learning how to work the unit.


Thanks!

[06MonteSS]

it would probably be between +1.xx to +3.xx

[Cooter]

OK. Thanks