I have a similar problem... valves adjusted, strong runing engine with great economy and no smoke. Just doesnt liek to start when it gets too cold, unless I glow and crank a number of times.

I decided to change the fuel filters and ran some diesel purge through straight.

The car is always driven on the highway, so I dont see why there would be carbon buildup, but now it starts almost as if it was 90F out after one glow when sitting for days in 20F weather...

Id consider doing a diesel purge, especially if you drive around town a lot and the engine doesnt get worked too hard. You might have carboned uo glowplugs.

JMH

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
2008 ML320 CDI (199k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)