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Help - Idle speed

Discussion in 'A4/S4 forum(B5 Chassis)' started by cashins, Mar 25, 2008.

  1. cashins
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    cashins New Member

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    [Mar 25, 2008]
    The 1997 (p) 2.6SE (Auto) I bought 2 months ago has developed a problem which I think may be self inflicted.

    I changed the battery and ever since it insists on idling at 1500rpm (interesting in an auto). The revs drop to 1100 or so , then it instantly catches itself and jumps back up to the above.

    There is a twin wire with spade connectors which goes through the bulkhead directly in front of the battery, into the scuttle area which is not connected to anything but I can see no obvious place that it could have been connected to.

    Faults rarely appear from out-of the-blue if you have been working on a car. Is it possible that I could have dislodged this or something else while getting the battery in and out, so causing the problem?
    :unsure:

    David
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  3. AndyMac
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    AndyMac Moderator Staff Member Moderator

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    [Mar 25, 2008]
    Is the temp guage OK as it could be a temp sender fault which is very common and the ECU thinks the engine hasn't reached operating temp. Could be coincidence that this has happened with battery swap. There shouldn't be any spade connections on the battery terminals, probably some aftermarket wiring.
    #2
  4. sun and kath
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    sun and kath Member

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    [Mar 25, 2008]
    If you are drive by wire DBW (no throttle cable) then the throttle lost its sync when the battery was disconnect it. Try discconecting your battery again for a few mins, reconnect, leave ignition off for a min. (you should hear a wizzing ). then I turn ignition on for a min before starting. the throttle should have learnt its position.

    If this fails VAGCOM can re set the DRW throttle.
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  5. cashins
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    cashins New Member

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    [Mar 26, 2008]
    Thanks Guys, will have a look
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  6. cashins
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    cashins New Member

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    [Mar 28, 2008]
    Sorted, Vagcom, £20 off the books.

    Thanks again
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  7. Siena
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    Siena Active Member

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    [Mar 28, 2008]
    Glad you got it sorted out.

    I have the same A4, a 2.6 Quattro Sport, and even disconnecting the battery for a few seconds puts the ECU into limp-home, as it loses it's basic settings.
    #6

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