I'm new to the forum & MB Diesels, recently bought 300TD with 329K, after 9K miles it developed rough idle when warm, very low power off the line, I did valve adj. which was needed, but still rough idle, it will get up to speed & drive OK.will stall when I stop, idle is not rough when cold, since valve adj. starts right up, pulled injectors, (I know I should replace heat shields but have not yet) cleaned them, no change, when warm engine stalls when 1,2 & 3 inj. lines cracked, #4 spits fuel & does not stall, # 5 didn't stall, then did after RD bolt adj. removed RD bolt, tip seems OK, but now I'm lost as to where that should be set
air filter housing did not have significant oil so I don't think there's much blowby. filters fresh, tank drained & cleaned, screen OK. injector return lines do not seem to flow fuel when removed at injector while idling? could use a direction to go in.
any tips on adj. fuel linkage?

Did you try adjusting the rack dampner bolt?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Agreed, you may want to check your injectors too, any diesel truck repair shop should be able to help. A compression test may be in order as well.

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83 SD

84 CD

then I removed the RD bolt, tip seemed not worn, & re installed, not sure where it should be set. What is indicated by # 4 & #5 not stalling, or causing stumble, when line is cracked? Chuffer, posted recently that he had similar symptom, stall on cracking # 1,2 & 3 but not on 4 & 5 , does it indicate weak IP? I will do comp test when I can but as blowby is non existent & it starts very quickly I think comp is good, could problem be IP?

Just something I might try. Take the return line off the injection pump and see if there is any fuel output with engine running. If there is none perhaps the pump is not getting enough fuel. Fairly quick test.

It may be weak after all these years, and worn out. I have two side by side, the newer one, gold in color, has a stronger spring/pin. Classic symptom of RD bolt, after it warms up. If you had a different problem, it would usually be all the time. Could be an IP problem, yet that is quite involved, you may want to check other areas first.

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83 SD

84 CD

I have the RD bolt out, I can press it in with some effort with bare fingers, how much tension should there be?