Yes you have algae/fungus, whatever---Black crap . Here is the post on removing the tank and pressure washing.

240D fuel tank removal and cleaning

You will fight this for while. I did my daughters car last year and still replace the in line filter every 6 months or so with it being black. I use slimeX about every other tank and the dead algae/fungus is still showing up.

http://www.powerservice.com/slimex.asp

So just perceiver. But the car runs fine and eventually the in line clear filter will be a nice amber glow when used.

As posted it is not necessary to replace the rubber fuel lines. Save the cost of fuel line replacement for the new ULSD fuel coming this fall. All your lines will leak and weep due to the change in fuel formulation.

Get a new fuel tank screen and install it.


Dave

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1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car