Fuel trim help please
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TECH Regular
Joined: Jan 2002
Posts: 465
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From: Tulsa, OK
Fuel trim help please Hey guys, my LTFT's are staying at -19.5% and at idle the STFT's are pulling another -10% or so.
I just got it back from tuning last week and the bank 1 stft's were a little lean and I ended up replacing the intake manifold gaskets.
After that, both banks have been really rich. I can't find anything physically wrong with the truck. All I can find online is that too high fuel pressure
or stuck injectors could cause it. I've checked both and they're fine. Is there anyone who could take a look at my tune and a log and see if they see any
issues that could cause this? Thanks in advance for any help you can give.
'06 6.0, 223/226 .600 lift 112 LSA cam, PRC stage 2.5 5.3 heads, TBSS intake with 2010 Camaro gold blade throttle body and xlink.
I just got it back from tuning last week and the bank 1 stft's were a little lean and I ended up replacing the intake manifold gaskets.
After that, both banks have been really rich. I can't find anything physically wrong with the truck. All I can find online is that too high fuel pressure
or stuck injectors could cause it. I've checked both and they're fine. Is there anyone who could take a look at my tune and a log and see if they see any
issues that could cause this? Thanks in advance for any help you can give.
'06 6.0, 223/226 .600 lift 112 LSA cam, PRC stage 2.5 5.3 heads, TBSS intake with 2010 Camaro gold blade throttle body and xlink.
10 Second Club
Joined: Nov 2005
Posts: 933
Likes: 75
Looking at your maf chart, I would say to pull some fuel out and see what that does. Looks rich to me. Maybe you fixed the leak? Turn off the LTFT's for now until you get the idle fuel where you want it. I don't see a wideband. Just tune the low rpm with the stft's. They look ok except for the idle portion. When you load the calibration, be sure to turn on the scanner and clear fuel trims before driving. It will keep you from chasing your tail. Get a wideband to tune wot.
Last edited by dw456post; Jun 24, 2021 at 07:00 PM.
Not sure if this applies to you, but there is a bug in the flexfuel vehicles you need to check for. See if your ethanol content is showing the normal like 3% or if it's showing like 40%. I had this problem, CEL showed rich both banks, and trims maxxed out trying to pull fuel. The fix was to force an ethanol relearn in a good scan tool, I think I used my Tech II, maybe GDI can't remember. There is a fix from the dealer but apparently the problem still happens for some.
EDIT: I think this describes it:
EDIT: I think this describes it:
Last edited by mk3cn4; Jun 30, 2021 at 03:46 PM.
