747 programing

[Bruce Plecan]

  In this situation, wouldn't an EGT be a better choice for tuning?

  Nope, plug cuts.
  Just disable codes 13-44-45, disconnect the O2 sensor, and set the C/L enable temp to 255.
  You now have a fully open open loop chip, and no cycling of rich lean.
  Off road use only....
  Never totally rely on any one indictor of mixture, unless your using a WB and are sure of it.
  Even plugs can fool ya.
  Grumpy
     What truck was non-feedback?.  Some had open loop idle, but I haven't seen a non O2 equipped 747....  Some 749s were thou.
  Grumpy?
  Terry
    ----- Original Message ----- 
    From: Kevin Reynolds 
    To: gmecm at efi332.eng.ohio-state.edu 
    Sent: Thursday, December 09, 1999 8:52 PM
    Subject: 747 programing


    I'm just mentally mapping out the process I'll be using to get the right prom setup for my crossfire.
    Some trucks using the 747 were non feed back. I have both a vacuum gauge and Air/Fuel ratio gauge in the dash.
    Tuning would seem to be a lot easier if the O2 didn't keep swinging due to feedback adjustment. How does the non feed back setup differ from the rest? Can I just get a prom from a non feed back vehicle, tweak the settings where I want, and then burn those numbers into a feed back style prom? What am I missing? It just seems that for idle and steady state cruise conditions it would be easier to narrow down your numbers and get them right this way and then turn the feed back on to compensate for altitude/temp etc. 
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