Worn or bad rack dampner bolt will produce exactly the symptoms seen on the 617 engine -- shakes like crazy at idle, but runs prefectly at any higher speed.

What happens is that there is a harmonic vibration in the injection pump that exactly matches the harmonic of the spring on the fuel delivery control rack in the IP, with the result that at idle it ocsillates back and forth in harmony with the engine vibration. When the spring gets weak or the dampner bolt gets worn, it gets bad enough to cut the fuel off to some cylinders, causing the shake to get much worse.

Usually can be fixed by adjusting the dampner bolt in some, but eventually it can no longer be compensated for, and the pump will have to be disassembled and repaired. I'd not do that until something else needed fixed!

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!