Hello Mike and all the others,
First of all I'd like to thank you Mike for your help and all the good pieces of advice by phone, I do really appreciate.
I proceeded to all the check you told me to do as well as the softair charge hose consolidation. It helps, not completely but it does help so I ordered a brand new one and it should be there wednesday or thursday. Next step is to remove the turbo for a thorough cleaning and gaskets/seals replacement. I found affordable rebuilt kits for £70. Did anybody perform a variable nozzle turbo rebuilt, if so any advice would be appreciated.
Thanks again Mike, it was really nice from you