Bmc 1500 injector pump problem - does anybody know about this nut

[daveandannie]

Hi
Please can any one advise me about the attached photo of my currently laid up

thornycroft t90 ‘ engines diesel injector.

injector is a cav 3246f857

The boat is a 1980 Moody 36 mark 1.

Ive had the boat a month and love it.

However ive had a lot of low idle cut out problems which seems to have been resolved immediately for approx a day by fuel filter changes. i’m assuming old fuel.

I will clean out the tank when I get it back.

After some air locks ive learnt how to bleed from lift pump to filter to injector pump inlet, side bleed vent and the ‘vent’ shown in the circles yellow photo above.

At sea following a blockage, stall, filter change at sea i managed to shear the vent nut whilst bleeding
i then (after mooring up under sail) managed to extract the circled hollow bolt spring retaining nut with rubber, and from this I managed to extract the broken threaded shank of a vent screw.

I’ve tried to wing it home by putting in a brass nut that I borrowed from the lampshade, but no big quantity of fuel cones out of high pressure lines E.g when I crack an injector so I can’t start the engine, and am laid up on at a very considerate and helpful yacht clubs swing moorings.

I can’t find info on this mechanism in my manuals or parts list.

Does this need careful adjustment ? I.E spring and hollow tubes etc or is it simply bleed point ? Surely not just a bleed point?

please can anyone advise how to set this if it needs careful adjustment ?
Does anyone know where I can get the little bleed screw Ive sheared off ?

Any advice gratefully received, I’m hoping to get back to the boat tommorrow to get it running and hoping not to have take injector pump out for a check over.
it was running sweetly when it ran.

Thanks

Dave

 

[Seastoke]

Try posting o

Hi
Please can any one advise me about the attached photo of my currently laid up

thornycroft t90 ‘ engines diesel injector.

injector is a cav 3246f857

The boat is a 1980 Moody 36 mark 1.

Ive had the boat a month and love it.

However ive had a lot of low idle cut out problems which seems to have been resolved immediately for approx a day by fuel filter changes. i’m assuming old fuel.

I will clean out the tank when I get it back.

After some air locks ive learnt how to bleed from lift pump to filter to injector pump inlet, side bleed vent and the ‘vent’ shown in the circles yellow photo above.

At sea following a blockage, stall, filter change at sea i managed to shear the vent nut whilst bleeding
i then (after mooring up under sail) managed to extract the circled hollow bolt spring retaining nut with rubber, and from this I managed to extract the broken threaded shank of a vent screw.

I’ve tried to wing it home by putting in a brass nut that I borrowed from the lampshade, but no big quantity of fuel cones out of high pressure lines E.g when I crack an injector so I can’t start the engine, and am laid up on at a very considerate and helpful yacht clubs swing moorings.

I can’t find info on this mechanism in my manuals or parts list.

Does this need careful adjustment ? I.E spring and hollow tubes etc or is it simply bleed point ? Surely not just a bleed point?

please can anyone advise how to set this if it needs careful adjustment ?
Does anyone know where I can get the little bleed screw Ive sheared off ?

Any advice gratefully received, I’m hoping to get back to the boat tommorrow to get it running and hoping not to have take injector pump out for a check over.
it was running sweetly when it ran.

Thanks

Dave

n scutlebut

 

[Rappey]

That assembly is part of the metering valve, damping valve/ governor. It seems quite a process to set it up if its been moved.
It is also a bleed point but only the top bolt should ever be moved .
Do you know when it was last serviced ? It may be worth getting it done as modern biodiesel can destroy seals inside leading to fuel leaking into the crank case. New seals are resistant to aggressive fuel.
Calcutt boats specialise in bmc and parts. ASAP supplies also stock a large amount of parts.
They are complete pita to bleed, often taking a few goes and will never start with any air in the system but great engines when running correctly.