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Strangely long cold start

Acheron Oct 3, 2012

  1. Acheron

    Acheron Active Member

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    So I had my remapped by from Revo stage 1 to stage 2 and the very next day I noticed that my cold starts have increased in length by probably around 10x for some strange reason:



    Essentially the car idles @ 1100rpm for over a minute now with the exhaust making a hell of racket until it slowly drops down to the usual 900rpm. Now I'm not sure if it's just coincidental or if the map has resulted in this, but I did query this with Revo who stated that it's due to the decat and the increased time taken for the sensor to warm up without the catalytic converter in place to absorb heat generated by the "SAI" (Secondary Air Injection?).

    The above would make sense, BUT I've had the decat in for quite a while and the issue only started recently (after the new map)

    Any ideas?
     
    Last edited by a moderator: Aug 15, 2014
  2. mjr901

    mjr901 Parts Manager - (Main Dealer) Gold Supporter Audi S3 Audi Main Dealer

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    Not gonna lie buddy, that sounds horrific.....

    My S3 does its usual cold start like yours, so that length of time is normal, and all is fine, but yours sounds rough?

    ive got full 100 cell milltek and mines silky smooth...

    If thats the original backbox have a look at the valve that opens and closes with increased throttle as it could be rattling around.

    As after the initial warm up has finished all goes quiet... ie less revs so no need for increased outlets ie, valve shut.
     
  3. jaydav2306

    jaydav2306 Member

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    I had mine failedto start for the first time the other day, the revs dipped and it felt like it wanted to not start then comes to life, I have had the plugs changed as well, what else can cause dodgy starts??
     
  4. mjr901

    mjr901 Parts Manager - (Main Dealer) Gold Supporter Audi S3 Audi Main Dealer

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    Sounds like air mass sensor to me.
     
  5. RYes3

    RYes3 Active Member Team Nardo Audi RS3

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    I'm sure I read somewhere the other day that someone had had an update to their Revo map and this was an issue they had seem too. They didn't like the map and went back to the previous version I believe.
     
  6. Twizzler

    Twizzler Active Member

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    My Countax sounds just like that and I've not had it remapped yet.
     
  7. Silky-S3

    Silky-S3 Is loving his new 8V S3!

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    That's well rough, mine S2+ does not do that at all. Something is amiss for sure!
     
  8. Acheron

    Acheron Active Member

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    Not sure if it's perhaps related to the fact that it is a non-resonated, complete decat section (no mini/sport cat) which is quite a bit bigger than the stock pipe (76mm) or perhaps even the grade of stainless used that gives it an almost tinny quality at low revs.

    I'm pretty stumped actually. :crying:
     
  9. S.

    S. Well-Known Member Team Ibis TFSI Owners Group quattro Audi S3 Manual

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    my exhaust snapped 2-3 times, broken mounts and it did make some kind of rattle noise.
    get under the car, and take look at the mounts near the turbo. that might be causing issues. mine did.
     
  10. Acheron

    Acheron Active Member

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    So the DP itself doesnt appear to be the culprit after cold starting the car on a lift and listening for any potential knocking from underneath.

    Looking into the issue I've seen everthing from the rear PCV hose, various vaccuum lines or even exhaust lifters as being a possible cause. Anybody that can confirm, deny, shed some light on those?
     

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