smoky and noisy
 

I have a Mercedes C 200 diesel 1995 and the problem with it is that it was throwing black smoke as you were driving,the car had done about 140,000 mls,so I had the injectors reconditioned,but it was still no better so I took the injection pump off to have it checked out,the pump checked out fine,re-assembled everything and still no better and now the engine has developed a heavy diesel knock as if the timing is to far advanced.I re-checked the timing with M.B.tool and is ok,I have also checked pre-heat chambers and ok,blanked off EGR valve and smoke is a little better,it also smokes lightly when it is idling,but it does not knock,compressions are fine,any ideas out there
much appreciated
Rob.