1983 mercedes diesel 300sd turbo: After starting the car, the engine sounds rough at idle , but once i rev the engine it goes away... This happens only when the engine is at idle , when i am running, it is smooth running.
Does anyone have any ideas how i can improve this on my car... ?

 

First - have the valves adjusted (could cost from $150 from a good benz mechanic to upwards of $300 at your local MB Dealer).

Second, find a diesel shop that is authorized to work on Bosch injectors, pull them out, and have them check them. They will check pattern, and the 'pop' pressure to see if they're in spec. Locally, they charge $2 an injector to check them - takes them about a minute a piece, so it shouldn't be much.

That's just my opinion though.