We are at
anchor behind Isle Brehat, in North Brittany. Yesterday we bought the most delicious things at the weekly market in Tregieur, and I cooked them last night, freshly killed chicken with delicious Roscoff onions in olive
oil, fresh green beans. Ah, life is sweet.
Except that I am troubled again by my main
engine, a
Yanmar 4JH3 HTE, 100 horsepower turbocharged and intercooled, next to last generation so purely mechanical
fuel injection.
I have had this problem off and on for two years -- the
engine will lose revs. It happened once in a storm at night in extremely rough conditions -- engine wouldn't rev past 2300 or so so I shut it down. When we got into port I discovered that the engine had puked
oil all over the place, apparently through the breather. I came to the conclusion that the turbo was gummed up by the oil. The problem went away by itself.
Later from time to time the engine would fail to make max revs (3800 rpm), but would usually run up to 2800 or 3000, which is all I ever use anyway. I assumed that the turbo was acting up and needed
washing (on the list). It seemed like it would happen especially after rough
weather or after a period of running at low
RPM.
Since about a month ago, I have had the problem of the engine refusing to rev over 3000. I was planning to wash the turbo this week. But now it's suddenly really bad again -- like two years ago. It might run up to 3000 briefly out of
gear, but falls off again to 2300 - 2400. Will maintain 2300 -- 2400 in
gear, but seems to stumble. At 2200 it's better. It happened at a nerve-wracking moment -- just as we were passing through a narrow gap in the rocks on the NW side of Brehat. And it happened after a series of hard rolls from the swell.
I am afraid it might fail altogether, then I would be in a nice pickle in this challenging place -- 14 meter tides and rocks as far as you can see. I don't even know where to look for a
Yanmar engineer (or parts) around here -- maybe in St. Malo, or maybe make a run for Jersey in the West
wind we have now.
The first thing I did was check the Racors -- clean as a whistle (as always -- we get good
fuel around here) and not a drop of
water. I have dual Racors with the vacuum gauge -- I switched to the other filter. No change. And no vacuum shown, which leads me to believe that there is no problem downstream of the Racors (or downstream of the
lift pump, I guess).
There is no unusual smoke, temperature fine, oil pressure fine.
What could it possibly be? Here are my principle suspects so far:
1. Probably not turbo -- otherwise the engine should rev ok or at least much better out of gear, right? At this moment it makes little difference whether there's a load or not.
2.
Lift pump? If the lift pump is not getting fuel through, that would account for these symptoms, it seems to me. But there is no fuel in the oil --
classic symptom of a bad lift pump.
3. Air leak in the fuel system somewhere? There are no fuel
leaks, no bubbles in the Racors. But I will try bleeding the fuel system and see if that helps. We changed the
fuel filter a few weeks ago and it made no difference in this problem.
4. Bad governor? Do those things go bad?
Anybody have any ideas?