Fuel delivery problem. Check the air flow meter venturi (probably dirty) -- if the air flow flap sticks, it will go way lean and stumble.

you should also replace the fuel filter and verify that the accumulator is good and that the pumps are working properly.

Bad O2 sensor isn't an impossiblity, either.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!