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Thread: AFR stays rich

  1. #1
    Lifetime Member SS2win's Avatar
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    Default AFR stays rich

    So I have a bit of a problem with my step daughters 1995 Z28. It's 24x converted LT1 with a P01 PCM and 6125 OS that runs really rich. It has no MAF so I've set it up as SD and when trying to dial in the VE, I get reasonable correction numbers but once they are applied, the tune dives back to 10-12:1 everywhere. Anyone have any tips for what to look for? I think I'm in over my head!
    2001 Camaro SS
    EFILive Custom OS3

  2. #2
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    Is your injector data correct?
    Ive never done that kinda swap so just my first thought was injector data..

  3. #3
    Lifetime Member SS2win's Avatar
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    They are the unknown factor. Bosch with the numbers marked off and what looks like flow rate burned into the body. good point
    2001 Camaro SS
    EFILive Custom OS3

  4. #4
    Lifetime Member SS2win's Avatar
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    I've been searching for a post that described verifying the injector data but having no luck. anyone remember this and have a link?
    2001 Camaro SS
    EFILive Custom OS3

  5. #5
    Lifetime Member Doc's Avatar
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    You have to consider that if you do not have the truth at KOEO, that is, 1) Fuel pump primed and pressurized to commanded. 2) Valid MAP/Baro scaled to your elevation. 3) Valid Displacement and Injector Data you are going to be shooting fish in a barrel. Xmas has come and gone, New Year's gift to your son and daughter-in-law, numbers matching, traceable injectors would cut to the chase if you can't get rational, repeatable performance out of the injectors you have?

    2000 Silverado Full Size 4x4: Forged 6.2, H/C F1R Procharger
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  6. #6
    Lifetime Member SS2win's Avatar
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    Yes for sure. We are already on that ... but not before trying a bunch of alternate injector data to see how the system responds. No matter what we do, everything works kinda opposite from what I'd expect, lean (17:1) at cold start up gradually going rich (10:1), it leans out when you tap the throttle then returns to rich. Crazy? yes. There's a lot of mods to the engine management I don't like so we're going to do a full wiring audit, put the MAF back in and replace the O2 sensors which are currently showing 0-45mv swing. Anyway, I was kinda hoping for an easy answer here! haha
    2001 Camaro SS
    EFILive Custom OS3

  7. #7
    Lifetime Member ChipsByAl's Avatar
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    Make sure the O2 sensors are not switched from bank to bank. I have seen it several times and causes some whacky issues. Easy to test, just disconnect one and expect it not to swing voltage.
    Al
    "Trash that carb and get Injected!"

  8. #8
    Lifetime Member SS2win's Avatar
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    Yeah, wow I can see that causing crazy issues! Thanks
    2001 Camaro SS
    EFILive Custom OS3

  9. #9
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    Check your O2 sensor heater circuit.

  10. #10
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    Did you fix the problem?

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