'82 240D 4 speed , just did the valves adjustment which has not been done for while.The valves prior the adjustment were pretty tight.
And now the car really vibrates at idle and would smooth out only if I increase the rpms with the inside knob.
Any ideas what is causing that.

Go drive the car very hard for 500 miles and readjust the valves.....chances are there is a lot of carbon built up and they need to reset....

Also look at having injectors rebuilt, new fuel filters, primer pump, adjust pressure relief valve and look at new engine/trans mounts....

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I had the injectors rebuilt about 1,600 miles ago(and they are still nailing when cold),also replaced fuel filters and mounts but don't know how to adjust pressure relief valve.Where is it located?
Primer pump? Why replacing it?It can cause vibration too?

I think this thread has the info needed....it is on the side of the injection pump near the head....the clear line that goes to the spin filter....follow it down to that side and that is where it is...in that banjo bolt.....most can be disassembled and stretched to 27mm I believe it is....this can cause injector noise too....

If the primer pump is the old style, it can very well be sucking air....which would cause a rough idle...

fuel pressure

Fuel pressure relief valve adjustment

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