Well, actually, I oversimplified in saying it was a fuel problem. You know, they always say there are three reasons why diesels have problems:
That's not far from the truth. But in the case I referred to, there were other problems as well.
My principal problem turned out to be an incredible amount of sludge in the crankcase/oilpan which was developed over the years because of my practice of changing oil by using a pump to suck oil out of the dipstick. Bad idea. You never get all the oil out, and especially the really dirty stuff in the pan.
One day, one of my mechanically-inclined sons pulled the oil plug out of the pan and you can't imagine the mess he dug out. Just incredible. After we got everything clean, by using some cleansers and multiple oil changes, I installed a special plug connected to an oil XChanger which allows me to change oil completely in less than 5 minutes, sucking it out of the oil pan and pumping it back in the same way with a reversible electric oil pump. Great system. I keep my oil and filters clean now, with little effort. Picture of this little puppy can be seen here: http://gallery.wdsg.com/Miscellaneous-Stuff/OilXchgr
A secondary problem turned out to be poor electrical connections on the ground side.
A tertiary problem was questionable fuel (I was then in the Caribbean), so I installed an onboard fuel polishing system, consisting of a humongous Raycor filter and a small electric fuel pump which takes the fuel from the bottom of my tank, runs it thru the filter, and pumps it back into the tank top. This system is completely independent of the regular Raycor filter bank on the engine, and has worked like a champ.
Once these three problems were fixed, and with clean oil in the engine, the 4-108 spun over like a top and became its old self again, starting easily in just a few seconds.
Never again had a starting problem.