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TDi (not so cold) starting problems...

Discussion in 'A4/S4 forum(B5 Chassis)' started by TeKnodriver, Nov 7, 2011.

  1. TeKnodriver
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    TeKnodriver Biodiesel Purrrr

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    [Nov 7, 2011]
    Hi all, hope someone can help with my latest problem:

    My TDi AFN is taking a good few seconds longer to start,
    last week I thought it was the cold weather and maybe a glowplug issue - but the problem is the same at 3 or 12 degrees C
    the glowplug light has flashed twice in the last month while driving, but has reset after pulling over and restarting.

    so,
    what should I check / replace?

    I have the EGR blocked and pipe removed - but tried replacing the EGR pipe and still the same

    the 4-pin coolant temp sender is only a couple of months old but I think this is the dash gauge sender not the ECU one (2-pin?)

    can't afford proper VAGcom but maybe worth getting a ebay-special?

    cheers, P)
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  3. a3tdi2001
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    a3tdi2001 Member

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    [Nov 7, 2011]
    Hi
    I've got the ASV engine which is similar. Don't think the ECU temperature sensor gives a glowplug light but it's worth changing it for an original one from the Audi. It's not worth risking an aftermarket sensor. I'd plump for the glowplugs first. Dealer ones are made by Beru and can be bought for around half the dealer prices eg: Audi A4 1999-2001 Electrical.
    #2
  4. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Nov 7, 2011]
    i use an ebay vagcom lead, its fine.

    It could easily be the glowplugs that are faulty. Does it start lumpy then pick up the cylinders after a few moments?

    I'd certainly suggest vagcom as a starting point.

    PS: Might be worth running dino derv and changing the fuel filter to rule out waxing issues from your bioderv.
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  5. TeKnodriver
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    TeKnodriver Biodiesel Purrrr

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    [Nov 7, 2011]
    thanks for replies!

    it takes 3-4 secs. longer to start in the mornings (from cold)
    starts rough then ok after 2-3 secs.
    power is same as usual - MPG maybe slightly lower? not sure

    It probably is the glowplugs - was just some older threads tat mention the TDi should start even without glowplugs at sub-zero temps?
    maybe that was for the V6 though..

    Fuel filte was changed 2K miles ago but maybe geting restrictive now it's colder
    [looking into electric pre-heater]

    Aragorn, re. the vag-com, does this look like the right one?
    eBay - The UK's Online Marketplace
    finally borrowed a Windows laptop to run it on so think I'll have a scan first

    P)
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  6. S4_dan
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    S4_dan Fire up the Quattro! VCDS Map User

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    [Nov 7, 2011]
    #5
  7. TeKnodriver
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    TeKnodriver Biodiesel Purrrr

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    [Nov 21, 2011]
    UPDATE:
    starting was still rough in mornings - was leaving a cloud of smoke on startup too.
    today I noticed strong smell of biodiesel in the cabin and saw drips left on the road behind me...
    looked under the hood to find one of the injector return hoses p155ing bio onto the engine!

    all return hoses now replaced (old ones had the outer cotton braid)

    and that seems to have improved the starting!

    seems the air leak was there before the hose split enough to spill the fuel

    [and yes this also happens to people running standard diesel]
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  8. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Nov 21, 2011]
    Yeh, it does, but all these rubber pipes are at a greater risk on Bio.

    Its probably been leaking for a while, but only just got bad enough to actually piss out.
    #7
  9. ScottD3
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    ScottD3 I want your faulty electronics Supporter

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    [Nov 21, 2011]
    You got it going, that good.

    I replaced all rubber hoses on my afn engine after I cleaned the injectors just to make sure. They did not loom to good.

    what oil you using?

    we stopped using palm couple of weeks ago.
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  10. TeKnodriver
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    TeKnodriver Biodiesel Purrrr

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    [Nov 21, 2011]
    not making it myself, get it from Purefuels in North London -
    pretty sure he doesn't put plam in there at all
    they've started adding winterizer and cetane booster for the cold a couple o weeks ago though so no probs there
    #9
  11. marktdisport
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    marktdisport Active Member

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    [Nov 21, 2011]
    think your signature says it all BIO DIESEL !!!! it will eventually eat every seal going.... this is probably why you getting issues.....injector seals etc !!!!
    #10
  12. ScottD3
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    ScottD3 I want your faulty electronics Supporter

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    [Nov 21, 2011]
    injector seals are metal.
    #11
  13. marktdisport
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    marktdisport Active Member

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    [Nov 21, 2011]
    sorry scott was meaning to put fuel injector pump seals etc but bio still aint great stuff they tryed it in our truck and we had more recovery trucks in 1 week than in 10 yrs
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  14. TeKnodriver
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    TeKnodriver Biodiesel Purrrr

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    [Nov 21, 2011]
    There are plenty of ways badly made or filtered Bio can ruin an engine,
    however, eating the seals shouldn't be one of them - synthetic 'rubbers' are unaffected - hence why Audi warranty would cover using EN-standard B100 [it's in the owner's manual]
    if anything the problems caused by ULSD are greater as it drys-out and shrinks seals.

    but this is possibly starting to go off topic... :blush:
    there are plenty of threads regarding these issues on TDI Club - some over 20 pages long...
    #13
  15. ScottD3
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    ScottD3 I want your faulty electronics Supporter

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    [Nov 21, 2011]
    not a problem but I have to agree with TeK.
    we can't talk about the fuel you used but the stuff we make (me and my dad) is fine and no issues over 4 years and 4 cars (2 long term and 2 short term).

    we are so confident its about to go in to his new v10 touareg.


    it only counts as off topic if the orignal topic it talked about or something, lol :)

    but I agree with you.
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  16. TeKnodriver
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    TeKnodriver Biodiesel Purrrr

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    [Nov 21, 2011]
    Scott, I'll have to ask you soon how you get on with the V10 TDi...
    is it a PD or CR diesel?
    I was put-off running bio in anything more recent than rotary-pumps
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  17. ScottD3
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    ScottD3 I want your faulty electronics Supporter

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    [Nov 21, 2011]
    give us a couple of month and I'll let you know.
    Not sure which one it is.
    most of the research we've done show issues with the bio thinning normal engine oil over several thousand miles, it should not be a problem for him cause we change the oil every 4k-6k any way.
    time will tell.
    #16

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