In article ,
"Albe V°" wrote:

My Volvo MD2030 diesel engine experiences a problem since last month.

Normally running at about 2400rpm (that's my cruise rpm), it suddendly
goes down of rpm, approximately at the minimum rotation speed, for few
seconds. Then, with no apparent explication, it returns to previous rpm
rotation.

My first thought was something like the fuel tank strainer, which Howard
covered well. A second thought is an intermittent air leak that
(wonderfully) self-clears. That it only seems to happen at 2400 points
to a restriction in the line (try another Racor filter & replace the
on-engine primary) or possibly a marginal lift pump. Try boosting to
above 2400 and see if it happens faster.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Dopo dura riflessione, Jere Lull ha scritto :
My first thought was something like the fuel tank strainer, which Howard
covered well.


Well done, guys.

That one was the problem.

At the present, we just cleaned the fuel line BEFORE the filter and
replaced the filter itself (it was factory new, anyway we replaced it),
but as soon as the boat will stop for few days, we'll dismount the tank
and we'll wash it (Croatia fuel is really dirt...).

Thanks you all.

Alberto

--
"Se viriamo, viriamo viriamo viriamo;
Se andiamo dritti, viriamo"
(Cit. "il tattico")