As mentioned in the engine overview section, the most frequent and intractable problem with the Virage is cracked pipes in the vacuum system. The engine management system depends on a consistent and full vacuum from the manifold being maintained. There is a rats nest of piping between the manifold, the absolute pressure sensors, the fuel pressure regulator valves, and the vacuum chamber for this system, all of which depends on a solid vacuum. However the old polyvon tubing is now perishing on almost all Virages, and this leads to erratic running and sometimes complete engine stoppage. The pipes move and expand as the car warms up and is driven, and this accounts for the inconsistent and unpredictable behaviour of the car, which has driven many owners (including us) to distraction.
No Aston main dealer or specialist we have seen has ever even mentioned this problem, let alone offered to fix it. And part of the problem is that replacing the pipes is a complex and long job (that took G*rry over 16 hours). Plus there is no general parts manual or ‘how to’ guide to help you. This page offers all the info we have gleaned on the process. This includes schematics of the plenum chamber assembly and a schematic of the pipe layout, a reasonably detailed description of where the schematics differ from reality and a description of a novel method of fixing two of the critical pipes that does not involve removing the plenum chamber. So here it all is. In almost every case, right click the link and select ‘save link as’ to download.