Breather valve on diesel tank?

[Vega1447]

Hi Steve and all.

I was on my Vega a week ago and the engine wouldnt start; starter worked
fine and smoke came out the tailpipe initially, engine coughed and tried
to fire up but no go.

Naturally I suspected a fuel problem so I bled the fuel system, first at
the fine filter, then at the fuel pump, finally at the injectors.
All well and engine started fine.

BUT:

When I bled at the fine filter I used a rubber outboard motor squeeze
bulb (that I fitted last year between the tank and the water trap) to
pump fuel through to the fine filter.

The bulb didnt "go hard" and it took longer than it should to get fuel
through to the fine filter bleed point.

This is exactly what happens with a petrol outboard engine when the
breather valve on the tank is left closed.

The tank is almost full so I suspect that the fuel pump is sucking fuel
from a tank which is not drawing in enough air when fuel is taken?

Are breather valves standard fittings? Should I look for a blockage in
the breather valve if there is one?

I took the boat for a sail and engine started fine when I came back to
marina but I don't like mysteries.. :-(

Advice welcome,

thanks,

John
V 1447 Breakaway

--
John A. Kinsella Ph: +353-61-202148 (Direct)
+353-61-333644 x 2148 (Switch)
Mathematics Dept. e-mail: John.Kinsella@...
University of Limerick FAX: +353-61-334927
IRELAND Web: John Kinsella's Website

 

[bobnlesafloat]

...Are breather valves standard fittings? Should I look for a blockage in
the breather valve if there is one?...

There's one on ours (and every other boat I've looked at that closely) just a 1/2" pipe from the top to an air-vent in the coaming.

A blockage is a possibility - we'd friends who had 'fuel-choking' problems in Italy a couple of years ago; they discovered that the vent fitting had lost its mesh and a small ant colony had taken the opportunity to build a nest inside the breather pipe - it was amazing (you could see its structure through the transparent pipe wall) and took up about an 18" length of their 3/4" pipe

 

[Vega1447]

Thanks for that.
A previous owner moved the tank from the bilge to port cockpit locker.

It looks like he didn't refit the pipe to the airvent in the coaming...

John

Bob Carlisle wrote: