Results 1 to 5 of 5

Thread: afr on dash vs. afr on log

  1. #1
    Tuner in Training
    Join Date
    Dec 2007
    Posts
    13

    afr on dash vs. afr on log

    have been dialing in the car and once I got it on point to my understandings.. afr on my datalogging is spot on and afr on my dash reading pig rich.. am I doing something wrong??? doing flex fuel tuning btw. is this usual or am I doing something really wrong? WOT fueling on the log is right at .82-.85(not commanded afr) but showing afr of 10.2-11.3 on the dash. car is a 2018 GT.

    i'll try uploading a log file tomorrow since I didn't bring the laptop home with me. I just keep thinking about it and want to get the thorn off my back. any help is appreciated. thanks in advance.

  2. #2
    Advanced Tuner
    Join Date
    Aug 2006
    Location
    Arizona
    Posts
    232
    Depending on the ethanol content, that dash reading may be correct. Just go by the lambda reading in the scanner.

  3. #3
    Advanced Tuner
    Join Date
    Mar 2010
    Location
    New Orleans, LA
    Posts
    630
    the stupid idiots at ford used AFR for the dash gauge instead of lambda so you have to factor in the stoich value its currently at in order to know if its rich or lean. Without knowing that the gauge in itself is pretty useless.

    if your logged lambda is where you set it and your fuel trims are good then just ignore the gauge

  4. #4
    Got a question.. even if it was a gasoline scaled read out from lambda on the dash shouldn't it still be accurate?

    .82 lambda read out on gasoline scale is still roughly 12 : 1. The o2 sensor doesn't care about the fuel type... just the o2 left.
    Why would e85 change the gauge readout?
    This seems to be a common thing with e85 but it doesn't seem like it should be.

    Command .82 lambda in 93 octane and then in e85... if the o2 scale is set to gasoline shouldn't the final reading the same?

  5. #5
    Advanced Tuner
    Join Date
    Aug 2006
    Location
    Arizona
    Posts
    232
    Again, Go by lambda in the scanner.
    2009.5 PBM G8 GXP M6 W/Roof-Self tune, OBX LTs, Kooks axleback, LSA blower, cam,
    Monster LT1-SC clutch, flex fuel, 12 psi [email protected] 1,800 D.A
    2007 TBSS-Self tune, bolt ons [email protected], 1,900 D.A
    1991 GMC Syclone- Self tune/catback 12.8@104, 4,200ft D.A