I need help tunning...LTFT
I need help tunning...LTFT I 've read all kinds of posts about LTFT and STFT! My question is how do I tune, so that the LTFT arent bouncing around so much?? I'm seeing as high as +18% LTFT and as low as 3%. Is this normal? I have Efi Live so any help would be appreciated. Thanks
It's all in your VE table and MAF table (if you're running a MAF). Disconnect your MAF and get your VE table closer to what it really is based on your fuel trims...LTFT's to start - then turn the LTFT's off and use the STFT's. Once you get the VE table dialed in, do the same with the MAF. It's relatively simple if you create your maps in the scanner to replicate what you want to change in the tuning software. Don't forget, you'll need access to a wideband O2 for WOT. But, this should get your part throttle closer. Let us know if you get stuck. We can help better the more specific you are.
Nice! thanks...so I need to disconnect the MAF sensor completely?? DO i need to turn off the DTC code for it as well?? And how do I disable fuel trims?? I dont see the option to do that in here? Thanks again
Ok heres the update...I went outside and disconnected the MAFS... Nothing happened though! I start the truck everything seems to be running fine. No SES code!! And it is stuck in Open Loop so my fuel trims arent changing!! What am I doing wrong?? THanks again
Ok...couple of things we may have missed here.
Running speed-density (aka SD or no MAF) can be accomplished one of two ways. Unplug the MAF completely (which should throw a MIL aka SES light within 2 minutes) or change the MAF high fail freq. to 0 and the number of failures to 1 with the MAF still plugged in. That can be done in the Engine Diagnostics>MAF>Parameters in EFI Live. If you want to turn off the SES light, you can do that too in the MIL section just above (turn off the first three MAF MILs).
Second, you want to ensure optimum spark. Running SD, your PCM reverts to the low octane spark map. Copy the high octane table to the low to resolve this.
Fuel trims can be enabled/disabled in Engine>Fuel>Trim>Parameters. While you're in Engine>Fuel, go to DFCO and change the enable temp to the max number (250*F).
Your truck probably never entered closed loop because it was still warming up. If you don't go to closed loop after 2 or 3 minutes, then there's a problem. The O2 sensors need those 2 or 3 minutes to warm up though.
This is how I prepare to tune in SD. It's also in most of the write-ups in the stickies. If you have trouble getting this far, you may want to spend a lot more time reading up on this before you actually go out and do anything.
Running speed-density (aka SD or no MAF) can be accomplished one of two ways. Unplug the MAF completely (which should throw a MIL aka SES light within 2 minutes) or change the MAF high fail freq. to 0 and the number of failures to 1 with the MAF still plugged in. That can be done in the Engine Diagnostics>MAF>Parameters in EFI Live. If you want to turn off the SES light, you can do that too in the MIL section just above (turn off the first three MAF MILs).
Second, you want to ensure optimum spark. Running SD, your PCM reverts to the low octane spark map. Copy the high octane table to the low to resolve this.
Fuel trims can be enabled/disabled in Engine>Fuel>Trim>Parameters. While you're in Engine>Fuel, go to DFCO and change the enable temp to the max number (250*F).
Your truck probably never entered closed loop because it was still warming up. If you don't go to closed loop after 2 or 3 minutes, then there's a problem. The O2 sensors need those 2 or 3 minutes to warm up though.
This is how I prepare to tune in SD. It's also in most of the write-ups in the stickies. If you have trouble getting this far, you may want to spend a lot more time reading up on this before you actually go out and do anything.
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Sorry io should've reupdated this: Thanks for all your help i figured out the problem! I got most of my LTFT down to -1's or so but im still working on it. After im done tuning for LTFT's how do i do the same for STFT? Thanks again for all your help
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