Cindy has the answer. If a diesel quits while running 99 times out of 100
it is a lack of fuel due to a blockage or an air leak.
I had a very similar experience bringing my Vineyard Vixen 29 down from
main. My symptoms were similar. did you have a slight rise in RPM just
before it died.
I was towed to Brown's in Gloucester. they too did not have the time to
look at it. The mechanic told me what I told you.
I started at the fuel intake and went all the way to the engine and couldn't
find it. He said to keep looking.
I resorted to blowing (lips on fuel line) from the engine back to the tank
in sections. The section from the fuel filter to the tank seemed tank. I
dismantled the intake piping (did I say I had to remove the tank from the
boat?) and there it was. A small screen plugged with algae.
Some genius years ago had installed a screen at the intake I guess to stop
sucking up sludge from the tank. Unfortunately when it got plugged, the
screen got sucked into the piping and stuck at a joint where it was
forgotten until I was alone in the Gulf of Maine.

Seek and ye shall find either an air leak or, more likely a blockage

--
Dennis Gibbons
dkgibbons at optonline dot net
"Cindy Ballreich" wrote in message
...
wrote:
Cindy Ballreich wrote:

possibly a dumb question
Did you try bleeding the engine?


Unfortunately, I did not have time this afternoon to bleed the fuel
system but will do so tomorrow.
Another possible clue is that in the morning, it was very very hard to
start. I first thought this was due to the cold weather but I knew
that was wrong as it was turning over easily. I am puzzled at why it
would suddenly get air in the lines although it has been 3 weeks since
I ran it.
I vaguely recall something about the return line having something to do
with hard starting or stalling.
What does the return line do? Although it obviously would seem to
return unused fuel from the injectors, why is it needed?


The reason that I asked is this sounds very similar to a problem we had
last year where there was the tiniest air leak. It took forever to
diagnose and almost drove my poor husband over the edge. It finally
turned out to be the petcock on the fuel tank. (This after replacing all
the vacuum side fuel lines and the lift pump!)

Friends of ours had the identical symptoms, but theirs turned out to be
a clogged fuel tank vent line. (spiders) Again, it took forever to find.

That pretty much exhausts my engine diagnostic abilities. I sure hope
you find the problem. Please let us know what it turns out to be.

Cindy