On my 300SD, the fuel pump is out of calibration, as a mechanic gave me some bad advice on how to smoothen the engine idling. He suggested that I loosen tne nozzle holders and "adjust them" left or right as needed. I have since learned that this should not be done. It's been about a couple years, and the car is fine, idles smooth, good power, very minimal smoke. The car is in mint condition and has only 130K Original miles. Is it worth replacing/recalibrating this fuel pump; should I be concerned that the engine might wear unevenly? Has anyone else ever had this happen to them>?