hi
checked pipes etc , there all fine !!
the pump from the 100 & A6 are 99% idenitical but there are some slight differences , we've got a diesel specialist not far away ...
so i think the cars gona be towed down there & see what he can find , if all fails theres a 2.8 Quattro engine my dad has his eye on , that could be going in , be ashame as he wanted the car orginally for the MPG but if all fails , MPH will win !!
cheers