I too suggest you use the search function. There is a lot of good info in previous posts on the vacuum system, the turbo system and its controls, valves and safety cutoffs, the ALDA, etc. , that you should find and study to get the big picture as to how the fuel/turbo syatem works and how to maintain and trouble shoot it. Eventually you will see that there is a progression of things to do to check elements of the system before you have to bring in tech reinforcements. Also, my own experience is that these cars are so old now that we get old-age problems that shop techs sometimes have trouble figuring out because they are busy trying to keep up with new models for which owners are willing to pay big repair bills. This forum is the absolute best place for you to start. As you narrow down the problem, come back on the forum with more specific questions and you will be amazed at the help you will get. ( with the 300TD wagon - wait till you get to the self leveling system issue - tons of invaluable help on this site for that) Good luck!