Leaking Diesel Injector Pump on W201?

[bruce.g.cameron]

I have a substantial diesel leak. Left a foot diameter puddle on the driveway. Seems to leak most just when the car is started from cold (its 30F here), and interestingly, it continued to leak for a time after I turned the car off. When I turned the car back on to test, it doesn't seem to leak (once warm). I have not been able to "catch it" (i.e. be under the car and watch where it is coming from)

Its hard to see, but the best guess I have is that it is coming from the yellow plastic piece where diesel enters the pump. The other candidates are the two hoses exiting the top of the pump. I have replaced the rubber on the line from the inline fuel filter to the pump.

Is that yellow piece supposed to be able to rotate? (it does on mine).

Anyone have other suggestions?

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1989 190D 146,000km