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2000 audi a4 1.8t sport , Help please ???

Discussion in 'A4/S4 forum(B5 Chassis)' started by ScottScodude30, Nov 29, 2012.

  1. ScottScodude30
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    ScottScodude30 Member

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    Can anyone help I've just fitted a atmos twin piston dv to my car and now it idles crappy and if you rev it will fall below 1k revs and cut out and when had diverted valve it was ok apart from about twice cutting out when revs dropped below 1k , I know it's prefered to have a re circ valve but really want to run the atmos DV and ideas why its cutting out when you drop revs please ??
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  2. Bradderz_1988
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    Bradderz_1988 Dont replace it, Upgrade it !!

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    Its because the maf has read the airflow and your dumping the air out of the systems thus for the engine runs rich as the A/F ratio has changed get a Forge DV 007p or 008 on it and mod the airbox or fit a dry flow open filter if you want more induction/dumping noise.
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  3. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    As he says.

    Air goes missing, ECU doesnt know airs gone missing, engine runs like ****.

    If its running like **** just idling then the DV isnt sealing properly, so its presumably broken or just cheap tat.
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  4. Oranoco
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    Oranoco Active Member

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    Twin piston won't help as that's typically what you would run on a car with a metering head like Bosch KE-Jetronic.

    My A4 runs an HKS SQV and was always fine up until getting back on the road, now I'm having a mare with it. It was on with no problems prior to my ban so fail to see any way the valve can be the cause. Also revs drop off completely even if just tickling the throttle so the DV doesn't open. Or even going from very light part throttle to coasting on gears. Dip the clutch at the junction and teh revs drop. So f***ing annoying
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  5. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    Twin piston types are recommended for cars with any sort of air flow metering, as they (Should) stay closed when at idle.

    Some other styles are designed in such a way that at idle with maximum vacuum the DV will lift off its seat slightly, which isnt a problem for cars using speed-density management, but on MAF equipped cars they act like huge air leaks.
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