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      11-25-2007, 07:59 AM   #113
scalbert
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Drives: '13 S4, '15 Q7
Join Date: Feb 2007
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Quote:
Originally Posted by Orb View Post
This did make me think that if there was a very minor leak the ECU may be adapting to it and overshooting under certain conditions so if this was the case then it may be possible that a mechanical device (diverter valve) is not responding predictably at certain boost levels.
The issue I find with a leak is that I do not see how it would cause a spike. The wastegate actuators are vacuum operated and default to open. So the DME (or PROcede) has to try and keep them closed otherwise no boost is made. A leak in the vacuum lines shoulc cause the system to build boost more slowly or not at all. My boost builds very quickly; too quick I suppose.
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