260E on going problem

[gtrpicker]

Well guys I still have the same problem of plugs fouling out after about 5 miles. Take them out and there black with soot.
I've changed almost everything, Fuel distribution unit, EHA , idle control, ignition unit, plugs, wires, cap and rotor, fuel filter. Duty cycle is at 43-52% at idle but rev it up and black smoke comes out the tail pipe, I have checked for vacuum leaks and thanks to MBDOC I found a big one, fixed it, but it made no difference to the problem so here's my question. Do the injectors wear out? I' have no idea what the mileage is. The vehicle is not trashed or anything like that but I've no idea what its previous life was. It seems strange that if thats the case all the injectors have worn out equally, as each plug is uniformally sooty.

Michael