part is.. Idle Stablisation Valve for a 1997 MK3 Golf GTI 16v. ABF engine.
via the exploded diagrams its goes into an inlet on the very front of the manifold in the very middle.
VW won't give out the part number over the phone..
I got given a number from a breakers yesterday which is 037 986 457 D
-however- this doesnt match the one for the valve that is on my car. (i think it ended in E?)
so either the breakers got it wrong, or my car has the wrong one.