Hey everyone, my Mercedes recently started idling high and becoming difficult to shut off without closing the intake valve under the hood. I figured it was a throttle linkage adjustment but was wrong. It eventually started smoking more and more, blue smoke, then when driving would smoke black. I took it to a shop where they spent TWO weeks trying to figure out what was wrong. They thought it was a problem with the injectors but couldn't know for sure until they checked the injection pump. I guess they said they needed a special bent wrench to take it apart and check it out. After a while they noticed the injection pump had no oil in it. So they filled it up and once they did the engine began to idle even higher.

What do you all think happened? What should I do at this point? It is currently parked in my garage, not safe to drive. I have seen kits to replace the diaphragm in the vacuum deal. Think that would solve it or is it something else? How bad can I expect the damage to be to an injection pump that ran dry? Would replacing that diaphragm be enough to get her purring again?

Thanks for any feedback.