Check those new seals for dirt and retorque them. It is fairly easy to fail to get them tightened properly so they leak, and if one is leaking badly, you will have severe engine shake below 1500 rpm or so. Usually have serious knock, too.
You can check for leaking seals by loosening the injector cap nuts one at a time -- when you get the the one with a leaking seal, the engine speed won't change. Having that engine running on three or four cylinders will rattle your teeth!
Proper torque is 20 to 25 ft/lbs three times -- that is, pull the pressure valve holder up to 25 ft/lbs, wait a few seconds, and pull again. You usually find that it takes two pulls before the holder stops rotating. Copper seals harden as you smash them between the holder and IP, so if you don't tighten the second and third time, they squeeze out a little.
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!