Hi
Thank you for taking the time to provide such a comprehensive answer, which has been of great help

Took off the manifold today and got the vacuum hoses checked properly and it turned out that there was a small crack in the hose from the vacuum tank to the split located under the manifold, changed the hose and got back the engine power that was missing :-)
When I had the manifold I also saw another part that had a bad hose, when I googled part number I got up pressure converter exhaust control and the hose that was bad went down to the bottom of the engine somewhere, will check closer tomorrow but is does anyone know where this goes and if it has an important function? This may well have something to do with the fact that I got so much smoke from the exhaust