Hey guys, kinda problem here.
1985 300d euro N/A engine, the car starts right up every time, however it seems like some days it idles like its missing(if it were a gas engine). it runs great, drives really good.

As far as maintenance I have changed all the filters, adjusted the valves(today) and ran some Diesel Kleen through it and put new diesel in. No change

any ideas? bad injectors? It does smoke some which I don't mind, not a lot especially when its warmed up it doesn't really smoke much at all. Its not life or death but I would like it to run right

The idle speed needs to be within the normal limits.

Misses at idle can be caused bay Air leaks.
Replace the 2 sections of Fuel Inlet Hose with 5/16” Fuel Hose from the Auto Parts Store. It is also rated for Diesel Fuel.

If you still have the shiny Aluminum bodied Hand Primer it is often the source of Air Leaks.

Look For cracks in the Plastic Primary Filter.

If it has not been done adjust the Valves

The Injectors may need to be checked and/or rebuilt.
On mine the passages #14 and #15 were entirely plugged solid with Carbon. When I rebuilt the Injectors with new Nozzles about 80% of my rough idle went away.
The idle Fuel amount is supposed to pass through the#14 and #15 passages.

Once the passages are plugged solidly I do not know of a Diesel Purge would wash out the Carbon. I believe the Chemical would just go around it.
However, periodic Diesel Purges would most likely keep the passages open if they were open to begin with.

German Made Monark Nozzles and Italian made Bosil Nozzles do not have the pictured passages so there nothing to get plugged up.
Monark Nozzles also cost less than the Stock Bosch Nozzle (made in India and will have the passages in it) or the Bosio

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84 300D, 82 Volvo 244Gl Diesel

wow great reply!! awesome information thank you!

Question on what you said though, the fuel line you speak of, is this the fuel line the is before and after the prefilter or another area?

My car has the black newer style hand primer so i should be good?

So Monark nozzles are recommended, can these be put into the existing injectors? This sounds like a great thing to do no matter what

Thanks!!

Max