turning on missfire detection

Discussion in 'Vagcom / VCDS' started by benthejettaman, Aug 15, 2013.

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  1. BENTHEJETTAMAN

    benthejettaman Forum Member

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    ive been trying to get down to the bottom of a missfire on a 2.8 bde engine. normal code readers and scanners was not detecting a single missfire, plugged it into vagcom this evening and turns out missfire detection has been disabled, i have tried reving it up and also driving it down the road to see if it would enable it but no luck so far!

    is there a way via vagcom to enable missfire detection?
     
    benthejettaman, Aug 15, 2013
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  2. GVK

    GVK Paid Member Paid Member

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    GVK, Aug 15, 2013
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  3. BENTHEJETTAMAN

    benthejettaman Forum Member

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    did find that link earlier,

    but answer to your question the only fault code stored is it cant see the ecu power supply relay

    have had it running on and of all day even driven it up and down the street a few times
     
    benthejettaman, Aug 15, 2013
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  4. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    If the engine accelerations for each firing event are over a stability threshold then you would have a misfire event. It would take a certain number of misfires to trigger an EOBD/OBD fault and turn on the MIL. So for example a coil pack dying which cause engine instability and over a drive cycle could trigger a misfire fault as well.
     
    Toyotec, Aug 15, 2013
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  5. rubjonny

    rubjonny Administrator Staff Member Admin

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    what was the code exactly, its probably the one you get when the ecu relay earth trigger isn't hooked up? my early looms were made like this until I knew better! you wire ecu pin 23 to G1/7 and switch the ecu relay to a 109 vr6/diesel one. However even if not wired up this code shouldn't cause any problems AFAIK?

    you'll need to feed the ecu and coils from G1/10 to take advantage of the ecu relay. if its a REALLY early loom I may have powered your ecu and coils from G1/4, again now I know better. if so just pop the pin out of g1/4 and pop into g1/10.

    if you dont wire in the g1/7 wire use ecu relay 30 from mk3 gti, if you do fit 109 relay as above :)
     
    rubjonny, Aug 16, 2013
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  6. BENTHEJETTAMAN

    benthejettaman Forum Member

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    which side of the ecu is pin 23 on?
     
    benthejettaman, Aug 17, 2013
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  7. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Typical pin out for these ECUs.

    [​IMG]


    Could post a screenshot of what the vagcom is saying. I suspect the function may have been switched off.
     
    Toyotec, Aug 18, 2013
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  8. GVK

    GVK Paid Member Paid Member

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    I think Barry has had what they call a 'thermal event' on his wiring loom. [8(]
     
    GVK, Aug 18, 2013
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  9. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Ooooppps!
     
    Toyotec, Aug 18, 2013
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  10. BENTHEJETTAMAN

    benthejettaman Forum Member

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    yep i think a bit to much has been previously turned, it can run on 3 and wont detedt a missfire

    thats one way of describing it lol
     
    benthejettaman, Aug 18, 2013
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  11. GVK

    GVK Paid Member Paid Member

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    I saw that posted on Pistonheads by an ex Ford/Prodrive engineer describing when the original Focus RS was being tested at Lommel in Belgium, one caught fire. [8(]

    I like sayings like that, it's like runs in paint - once described by a car painter as 'gravitational errors' lol
     
    GVK, Aug 18, 2013
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  12. rubjonny

    rubjonny Administrator Staff Member Admin

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    well if you send it back to me I will repair and build it properly for you if you like? depending on how knackered it is though :lol:
     
    rubjonny, Aug 19, 2013
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  13. GVK

    GVK Paid Member Paid Member

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    He's fixed it as far as I'm aware as he was in the car at Retro rides show at Prescott.
     
    GVK, Aug 19, 2013
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  14. rubjonny

    rubjonny Administrator Staff Member Admin

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    good show :thumbup:
     
    rubjonny, Aug 19, 2013
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  15. BENTHEJETTAMAN

    benthejettaman Forum Member

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    cheers for the offer jonny but yeah as gary has said i managed to fix it in time for the retro rides gathering, just a shame i didnt see your post on pin 23 earlier as i would of done that at the same time
     
    benthejettaman, Aug 19, 2013
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  16. rubjonny

    rubjonny Administrator Staff Member Admin

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    ah well, as i say i dont think it affects anything just makes ecu flag a code. what was the problem in the end then?
     
    rubjonny, Aug 20, 2013
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  17. BENTHEJETTAMAN

    benthejettaman Forum Member

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    COP's werent getting enough power, it was only when i put on 6 new coilpacks then it burnt the coil live out.

    still need to find some one who can look at my ecu as it should of been able to detect a missfire
     
    benthejettaman, Aug 20, 2013
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  18. rubjonny

    rubjonny Administrator Staff Member Admin

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    hmm on the main section of the loom or the part after that to the coils?
     
    rubjonny, Aug 21, 2013
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  19. BENTHEJETTAMAN

    benthejettaman Forum Member

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    main section of the loom going from the fuse box
     
    benthejettaman, Aug 21, 2013
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  20. rubjonny

    rubjonny Administrator Staff Member Admin

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    ah ok, looks like not good enough ign feed then due to using g1/4, or perhaps wire not beefy enough? this one is so early its not even in my list!
     
    rubjonny, Aug 21, 2013
    #20
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