aux air valve? Post Posted 30 December 2018, 2:01 PM #1610500 (In Topic #219869) jasonf Settling In hi , my 89 gti has poor idle when cold but starts fine and isles fine when warm, could the aux air valve be faulty? If so where is it located, only had mk1 a few weeks so learning. There are too many online users to list. Forum home Fuel Systems and Exhausts