Can ayone advise me where to locate the power boost control valve on a 2008 1.9 TDI diesel engine. I bought the part with 3 connectors for small tubing and an electrical plug in but I cant find it on the engine. Any advice please..

Its usually on the bulkhead but not sure if this generation had a large black box with all the solenoids combined into one unit.

That will be a BXE engine code, as stated already these don't have an N75 valve which will be the part you have bought, there is a big vacuum solenoid box on the bulkhead with 5 vacuum hoses attached to it. 

Very helpful folks I know the unit you are referring to.. the car part shop have given me the wrong part even though they sourced it from vehicle registration number.. i will get it exchanged. Can existing valve be cleaned to get me over the xmas..

I don't think so. I once tried cleaning one with compressed air in a can and only succeeded in killing the valve completely! They are a totally sealed unit, not cheap either unfortunately. 

Many thanks for that... i think is jyst bite the bullet and buy one as soon as i can...