Fitech running fat

Discussion in 'Fuel and Air Systems' started by Devo44, Oct 25, 2018.

  1. Devo44

    Devo44 Member

    Messages:
    17
    Likes Received:
    0
    Joined:
    Oct 24, 2018
    Location:
    95531
    Local Time:
    5:08 PM
    LONG story ill try to be short. 496 bbc .585 hyd roller cam alum ported chevy heads edelbrock rpm air gap tko 600 9" 3.70 gear ran great with qf 850 carb. switched to fitech 800 mean street. new fuel tank w/400lph pump bypass regulator at 43psi. cant get it to lean out no matter what. back fire and popping randomly at idle, no power when I step on it. plugs (e3) carbon fouled. msd 6al2, hei, accel coil 13* initial 32 total. called fitech twice said I had emi trouble or exhaust leak. emi would show fault code, but no fault code. no exhaust leak. so both techs I talked to said "I don't know what else it could be, sorry" REALLY! I have read a ton of tech tips and tried A LOT of different things to try and lean it out. compression 180 in all 8. set and reset valves 5 times. pulled and checked all valvetrain no broken valve springs. no bent pushrods. all rockers in good shape. anybody got a guess why this is untuneably rich? Think I just made up a word. thanks.
     
  2. Big Green Duster

    Big Green Duster Well-Known Member

    Messages:
    78
    Likes Received:
    57
    Joined:
    May 20, 2017
    Location:
    19020
    Local Time:
    8:08 PM
    Just a random shot in the dark but check the egr valve and the pcv to make sure its not something simple
     
  3. jimjimjimmy

    jimjimjimmy lobsterman FABO Gold Member

    Messages:
    3,942
    Likes Received:
    713
    Joined:
    Nov 2, 2010
    Location:
    p. e. i.
    View My Photos
    Local Time:
    9:08 PM
    I never seen anyone use a bypass regulator on a fitech it has its own built into it along with its own return and I think it requires over 50psi fuel pressure .
     
  4. Steven190

    Steven190 FABO Gold Member FABO Gold Member

    Messages:
    689
    Likes Received:
    255
    Joined:
    Jan 13, 2012
    Location:
    Omaha
    Local Time:
    7:08 PM
    Don't know much about the Fitech, I have the Fast. It has a section in the controller to set the air to fuel ratio for idle, cruise and wot. Then there is a screen for live settings as the car runs.
    Like Big says check the mechanicals first. good luck
     
  5. BrianT

    BrianT Let's go! FABO Gold Member

    Messages:
    5,197
    Likes Received:
    714
    Joined:
    Mar 13, 2007
    Location:
    Kansas City, Mo
    View My Photos
    Local Time:
    7:08 PM
    Your first post on a Mopar website is asking about a problem on a BBC? Man, you must be desperate for help. Welcome to FABO!
     
    • Agree Agree x 2
    • Like Like x 1
    • famous bob

      famous bob mopar misfit

      Messages:
      10,499
      Likes Received:
      2456
      Joined:
      Aug 14, 2011
      Location:
      okla
      Local Time:
      7:08 PM
      The 13 initial caught my attention ,
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      Devo,

      Did you hook up the wide band sensor? What is it reading? Is it sealed in the exhaust?

      Marion
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      The FiTech has a setup screen that allows for the basic engine parameters to be set also. To include AFR and Engine Cubes which will affect the fuel ratio.
       
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
      Yes the tech guy at fitech said the internal regulator is only capable of suppressing 340lph pumps. Mine is 400 so he said to bypass regulate it down to 43-46lbs.
       
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
      Ya all that has been done, reset and redone several times
       
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
      Yes it is. Says its running at 13.9
       
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
      I am! Feel like i just threw 1800$ in the shredder!
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      Is that at idle or partial or wide open throttle?
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      Idle and Part throttle could be at that AFR and that's perfectly fine. A tad rich but still ok. 14.7 AFR is the optimum for emissions at those throttle positions. 13.9 is ok and you will not notice any issues. On your ride you want to be at 12.7 max or so at Wide Open Throttle. The system will make the changes as you go from closed to open loop in the fuel table. Anything less than 80% throttle (TPS controlled) is closed loop, over 80% there is a different fuel and timing table for Oh Shit Mode! Look at your TPS readings on the screen and the corresponding AFR.

      Marion
       
      Last edited: Oct 25, 2018
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
      Idle. It smokes and pops randomly through exhaust
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      Naw, you will be just fine. I don't know if you are EFI savvy but it is light years ahead of a carb is an all purpose aspect. Hang in there. Check for vac leaks.
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      Is it controlling timing too or is your dizzy locked out?
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      Ok but that's not a rich AFR. Recheck the WB sensor, where is it located on the exhaust and what clock position is it at? It could be goobered up maybe. It must be airtight and the sensor itself clean and away from any water /moisture in the ex stream.
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      what about WOT?
       
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
       
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
      Yes its clocked correct i even removed and cleaned it. Dizzy is not controlled by efi unit.
       
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
      No power at wot. Sluggish
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      AFR at WOT?
       
    • Devo44

      Devo44 Member

      Messages:
      17
      Likes Received:
      0
      Joined:
      Oct 24, 2018
      Location:
      95531
      Local Time:
      5:08 PM
      I believe it was around 12.9
       
    • mario03srt

      mario03srt FABO Gold Member FABO Gold Member

      Messages:
      498
      Likes Received:
      105
      Joined:
      Apr 12, 2015
      Location:
      Amelia Oh
      Local Time:
      8:08 PM
      Devo,

      Ok so the unit says that it is not running rich. ;) But the plugs say maybe so and the way it runs also maybe.

      Do the 2 AFR setting values coincide with the readouts? 13.9 = 13.9 +/- a skosh or is it 13.1 = 13.9? Also WOT. So to try and be sure, go into the controller and adjust the AFR at idle to a lower or higher value and see the readout results.

      Also as a check see what the % fuel trim is at idle on the controller, mine is about -29% as it sets.