Car has been running beautifully ( several long trips but stuck in heavy traffic ) until two days ago. Suddenly started conking out on first stop ( as had done some years ago ) and not idling reliably. Swopped in the spare ISV (kept ready lubed) and all seemed OK until this morning when it became horribly(!) worse. Managed to get car back on driveway and started with the usual - MAF connector, ECU reset, throttle pot check; followed by Mityvac check on all small hoses. All OK. At idle, noticed the boost gauge some points off "usual" and then heard a whoosh on switch off. Removed ISV and - guess what - the small right angle hose from beneath the ISV to IM has split in almost the same place (again)!! Shoved in a bit of spare rad hose and normal running returned. I can only assume that the heat cycling and maybe being under a little stress when supported in its rubber harness has done for it again ( It was only 18 months old). Maybe worth checking yours - its the only bit not included in the Samco upgrade ( when I bought mine )..
Audi p/n 034 133 997 aa.
Audi p/n 034 133 997 aa.