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EVOscan Fuel trims never show up idle

Posted by Sjd6795, May 20, 2020

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  1. Sjd6795

    Sjd6795 Proven Member

    Joined May 14, 2014
    Wilsonville, Oregon
    So still tinkering with my tune to get AFR set perfect. I have seem to get idle to be near perfect it still shows a little rich after pulling up to a stop light around 12.5 then eventually comes back to around 14.

    However when I let the car idle for 16+ minutes my fuel trims never changed, I had to drive the car and LTFT finally showed up and was around 3-5% if I remember correctly. After coming back to idle LTFT went to 12.5% and stayed there. During the drive I also did a pull and AFR was 10.8 I can adjust scaling easy enough to lower that to 10.5 if needed, but my mid or high fuel trims never changed the value just stayed at 0.

    My cruising AFR is still rich but I believe I need to adjust fuel trim control points for maf smoothing?

    I took a shitty video with my phone after coming back to the apartment and letting the car idle. My o2 sensor voltage is bouncing as it should, RPM are perfect, Battery voltage is perfect, MAF hz perfect, and LTFT is stuck at 12.5 and no other fuel trim are reading.

    Street Build 748  13

    1997 Mitsubishi Eclipse GSX
    322 whp · 331 lb/ft · 2G DSM

    Street Build 1K  0

    1991 Eagle Talon TSi AWD
    manual · 1G DSM
  2. Mello

    Mello Proven Member

    Joined Jul 4, 2003
    Albuquerque, New Mexico
    Fuel trims only change when the O2 AFR's don't match the target AFR's. Check your Lo-Octane & Hi-Octane Fuel Map tables & see what they're set to.

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