I read all the threads and posts before posting this; thanks everyone for all the good experience and recommendations! Couldn't find anything similar on the forum.
I've got something really weird happening. FWIW, I've been a diesel mechanic since 1976, always rebuilt my own pickup truck...
I've got a 1990 TAMD31 A in a cute little Shamrock 20 that's been parked in a garage for 20 years; the engine only has 1,926 hours on it (barely broken in for a diesel!), but the injector lines have big rust flakes coming off them. Scared to go to sea like that, but new injector lines are $175...