I have very rough starting, often hard to start, on a 1989 300E. I have just replaced the injectors and seals. Shop says I have rust, varnish, or other debris washing through the fuel system, clogging tiny orifices, etc. Their mechanic showed me rust or something in the fuel being bled from the fuel distributor. After this was repeated on all of the nipples, the engine was idling better.
Once the car is started and the obstruction clears, the roughness largely disappears, but idle is still uneven.
I notice no rust or other material when bleeding fuel at the nipples on the fuel distributor, so the shop says try using commercial fuel line cleaners and if this does not do it in three tanks or so, the fuel distributor will need replacing. I have used STP Fuel Treatment and Slick 50 Fuel Treatment, but still have the very hard starting and rough running until whatever is clogging an orifice is dislodged. (This is the view I have gained from what seems to be a good shop)
If I really have nothing but hard starting due to debris in the fuel line I can live with this until I can afford another expensive repair, and use some more fuel line cleaners meanwhile. Question is, can I replace the fuel distributor myself? I have the usual array of combination wrenches 4-24mm, 1/4 and 3/8 sockets, allen sockets and basic hand tools. Am I properly equipped? After replacing the injectors, this looks easy enough. Am I missing something, believing this looks like a simple remove and replace job? Any advice, magic incantations, etc. would be sincerely appreciated, since it looks like a savings of $300 or so.
At the same time, can you recommend an alternative remedy, a different diagnosis, or even your favorite fuel line cleaner?