wierd afr's????

Discussion in 'Modifications And Maintenance' started by 95lwrx, Sep 9, 2007.

  1. 95lwrx
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    95lwrx Well-Known Member

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    so i have some new findings which are a little confusing, russ hooked up his wideband and we came up with some interesting results and neither of us can come up with anything definitive that could be causing the issue.

    so if anyone can make anything of this it would be greatly appreciated.
    thanks.

    first off at idle it is way too lean in the 15s even 16s to 1. turn on the a/c to put load on the motor it even goes leaner.

    next at cruising speeds it sits high 14s to 1 which is close to where it should be but still a bit high. and also when the car stutters while cruising or during slow acceleration the afr's jump way down in the 10:1 or 11:1 range which is way too rich for that situation.

    next is under hard acceleration, once into boost the car is running perfectly the way it should mid 10:1 afr's so once it switches to the map it runs the way it should.

    and i drove the car before i installed the ap and had the same stutter. so it's not the ap. i am starting to think there is possibly something messed up in the ecu? also no cel's come on during any of this.

    any thoughts, suggestions?
     
    95lwrx, Sep 9, 2007
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  2. hella_sti
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    hella_sti Well-Known Member

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    any data logs you could post? What are you tuning with, cobb street tuner?
     
    hella_sti, Sep 9, 2007
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  3. Nuke
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    Nuke Well-Known Member

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    hm, maybe that honda o2 sensor you put in?
     
    Nuke, Sep 9, 2007
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  4. 95lwrx
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    95lwrx Well-Known Member

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    no logs this is in accessport off the shelf stage 2 map.

    and these numbers are with the new oem subaru o2 sensor, the honda o2 ran even leaner than the subaru except on the map, without the drops in afr's while at steady speeds or slow accel.
     
    95lwrx, Sep 9, 2007
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  5. Dynapar
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    Dynapar Well-Known Member

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    could it be related to fuel pressure? maybe the pump is going on you or there isnt enough voltage being sent to the pump from the ecu (loose connection?) that would make it not run at full capacity?

    or maybe a sticky injector that only really opens up when the fuel pressure rises from stomping on it?

    i guess you just need to go WOT everywhere. to be safe.
     
    Dynapar, Sep 9, 2007
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  6. Nuke
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    Nuke Well-Known Member

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    LOL

    Cop: Do you know why I pulled you over?
    Driver: Because I have to stay in WOT the whole time to keep my afr safe.
    Cop: ????
     
    Nuke, Sep 9, 2007
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  7. 95lwrx
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    95lwrx Well-Known Member

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    there should be no loose connections since all of that is all factory wiring that i did not touch. pump should not be a problem, maybe the fuel pump controller is going bad(not sure if that is at all common though) i have ran some really good 3m fuel system cleaner through it(motor runs off of compressed can through fuel line) so there should not be any sticking injectors.

    when it cuts out when the afr's drop its like everything shuts off, feels like fuel cut but that is obviously not the problem since it goes way rich when it cuts out.



     
    95lwrx, Sep 9, 2007
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