I've recently aquired a 84 300d with 198k. The car is in good shape and I imagine that she has alot of life in her. I'm having serious rough idle problems when the engine gets to running temp. At first when the engine is cold it runs well but as it warms up it gets worse. I would imagine it might be an injector problem but I dont want to tear into something I dont have to. This problem has to be fixed because it shakes the stuffng out of you. I'm new to the forum and I think it's fantastic. If any one could give me a list of steps as far shooting this problem I would definetly be thankful!!!!!!
THANXS JP

JP

Rack pin adjustment -- see other posts. Classic IP problem with these cars, definitive cure is IP rebuild (very expensive), the rack pin adjustment usually fixes it.

What happens is that the rack that controls the fuel delivery in the injection pump by rotating the sleeves inside around the plungers has a spring to return it to idle position. As the IP gets older, the spring gets weak and lets the rack vibrate back and forth, causing variable fuel delivery at idle. It just happens to vibrate at a harmonic of engine vibration, so the vibration builds until your teeth rattle. Very irritating. Stops as soon as you raise the engine speed off idle.

There is a 14 mm nut on a 12 mm bolt on the back of the pump, lower passenger side, I think (I don't have one of these!). To adjust, run car til hot and shaking hard, put in gear, set parking brake and block wheels (or have a helper stand on the brakes), loosen the 14 mm nut and slowly screw the 12mm bolt in until the shaking stops. Run engine up a couple times, put back in gear, and re-check, then tighten 14mm nut while holding 12mm bolt in position. Don't over-adjust, just run it in until the idle smoothes out, or you will have cold start problems. You must do this adjustment with the car in gear, or you will have trouble getting it set correctly.

Check the other posts on this adjustment before you do it -- it's not hard, but more info will certainly help!

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!