OK. Thanks guys! Fuel quality is bad here. We ocasssionally have to drain the tank coz' there's very fine black mud - about 3-6months only. The pre-filter is the first to show signs and after cleaning the pre-fliter and the black stuff if there again (after about 3 weeks, we already drain the tank. I just want to take extra care of teh injectors (now that they are in good condition).
85' 300D Euro (W124)