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V6 HT leads

S4_dan Mar 20, 2012

  1. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    Hi,

    Still have a really random, extremely intermittent hesitation\miss-fire on my 2.8. It can happen on a flat road at steady constant speed, or it will happen on an slight incline. I can never get it to repeat. It does it when it wants to!

    The plugs and air filter are new. As it most other parts on the engine. Changing the TB hasn't made a difference. Only thing that does make a difference when its doing it, is putting my foot to the floor on the loud pedal and then back to where it was.

    My HT leads are unknown in terms of age. Does anyone have a set of working leads that i could borrow to see if it rectifies anything? I will pay for postage to and from and chuck in some beer tokens. That is still alot cheaper than a new set of HT leads!

    Also, there is no new DTC's. only my throttle body one which I have had sine owning the car and even changing the TB's over its still there!

    Dan
     
  2. audiv8quattro

    audiv8quattro Member

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    Hi mate I haven't got ht leads sorry but I've got a coil pack that I think is the same as yours if you want that mate,
     
  3. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    It could be my coil pack. I didn't think of that to be honest! Yeah if i could try that, that would be great.
     
  4. audiv8quattro

    audiv8quattro Member

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    Ok mate no worries here's part number 078 905 101c if you double check part numbers if it's the same pm me address and I'll send it to you,
     
  5. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    Ok will check it tomorrow at work and let you know.

    Cheers.
     
  6. audiv8quattro

    audiv8quattro Member

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    Ok mate, hopefully the right part as its just sitting here doing nothing and would rather it go to good use lol.
     
  7. GISXER711

    GISXER711 New Member

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    have you taken out the plugs as they will show if HT leads are working or which ones are not .
    if plug is black or wet then its not working , plug should be a cream white colour.
    i bought a set of HT leads from ebay for my 2.8 cost 90
     
  8. GISXER711

    GISXER711 New Member

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    also i know my HT leads needed replacing as when engine running i could hear tickinng , snick snick so i know not to tuch as would get a belt , new leads
     
  9. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    AudiV6Quattro... my part number is 078 905 104. Do you have ETKA do a part ref check?


    GISXER711....I can touch my leads although they do have a plastic tubing over the silicone wire. I have also had the car running in pitch black to see if i can see the wires lighting up like blackpool illuminations! The spark plugs are about 3k miles/5 months old. I will remove and check, but as its really intermittent i'd stab a guess that the plugs will be pretty much all the same.
     
  10. audiv8quattro

    audiv8quattro Member

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    Hi mate sorry I don't have etka but I did type part number into eBay and it's coming up as 2.6/2.8 audi a4 coil pack, I know that's not really that reliable but it might help
     
  11. murran

    murran Well-Known Member

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    dont see it being leads or the coil by the way you describe the fault as being under light throttle then clears if you boot it.
    a coil or lead letting the spark jump to earth would be most noticable under heavy throttle/full load/lowish revs when the coil has to produce more voltage because the spark finds it the hardest to jump the plug gap under those conditions.

    far more likely would be a dodgy injector intermittently not spraying correctly under light throttle/short duration.

    take them all off and send them off to be cleaned ultrasonically.
    ASNU Fuel Injector cleaning by post
     
  12. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    It's not always under light throttling though. It can do it whilst accelerating. When it does happen, i ALWAYS get 2 'pops' in the exhaust, then immediately, it's back to normal operation. Always to 'pops', never 1 or 3.

    Timing belt was replaced last year and i've covered over 8k miles before this issue started happen.

    Thinking coil pack/ leads could be logical in going to earth briefly??
     
  13. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    Just done that too, and your coils are individual with a llooonnnggg lead for the coils to connect to the car. Mine has very short lead and a 5 pin socket that i use. So i don't think those will fit my car sadly. :-(

    Trying to get hold of ETKA. I do have a copy somewhere....... but where?? lol
     
  14. audiv8quattro

    audiv8quattro Member

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    Ok mate no worries hope you get it sorted though. If it does turn out they can be modified to fit you can use bits of it which I doubt then drop me a pm.
     
  15. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    Ok cheers. Just run your part number through ETKA and it comes up with: 'Part number 078 905 101c not in stamm' but it finds my part number of 078 905 104 ok??

    Its version 7 update 622, if anyone can help?

    Edit:

    Sorted it now. Your coil is for ABC, AAH, ACZ V6 engines. (are they all 12V engines?)

    for 078 905 104 it only fits the ACK lump. So looks like I'm gonna need that specific part number?!
     
    Last edited: Mar 22, 2012
  16. murran

    murran Well-Known Member

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    yeah abc aah engines are the 12v ones.

    it possibly might be spark related then.

    but on the other hand if the injector isnt spraying properly the fuel might be getting sprayed at the inlet port wall and dribbling in thru the valve. then not burning the fuel properly but excess fuel is igniting off the red hot exhaust valve as it exits the cylinder?

    ive seen first hand on a bmw e36 m52b25 engine, the side of a piston melted away due to a leaking injector not spraying properly.

    just throwing ideas around here. :)
     

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