So I've been trying to educate myself a bit more as to how my Diesel engine operates, and how this relates to the experience I am having. The operating temp. compression test should be done in a day or two, giving me the first opportunity to go down one path or another. If, as I hope, the engine is sound, I will replace fuel filters, add biocide and do a purge. I don't expect a wholesale change in engine operation at this point, but am willing to be pleasantly surprised.

Given this is the way the scenario plays, I am inclined to think that timing may be the primary issue. The injector "test" was somewhat vague, and I keep going back to cold start. For me, it is a question of what changes after the initial 10 seconds of "perfect" running. Someone opined that residual glow plug heat might account for this. I haven't discounted that, but in a compression ignition environment, assuming the compression test is good, I would tend to look elsewhere.

As I understand it (please correct me if I am wrong!) there is a starting position for pump timing, and a running position. If the timing is accurate for starting, but shifts to run position and encounters problems, could this not be a good fit to the symptoms?

Anyway, I'm continuing to research, and will pass along what I find. Thanks for helping me along here!

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Chief

1991 350SD