Fuel shut-off lever position

[Mikexx]

After having trouble starting my engine (1.5D), I realise the return spring is pulling the shut-off lever too far and is shutting off the fuel.

Without going into detail the lever was subject to some force and so wondering if it might have rotated on the shaft.

Is this likely?

Are there any stops to limit rotation?

[TheBiscuits]

3 minutes ago, Mikexx said:

Without going into detail the lever was subject to some force

Did you upset Yoda?

[Mikexx]

17 minutes ago, TheBiscuits said:

Did you upset Yoda?

Hmm, if you remove the engine, its a very good idea to remove the cable attached to the lever!

[Tony Brooks]

6 hours ago, Mikexx said:

After having trouble starting my engine (1.5D), I realise the return spring is pulling the shut-off lever too far and is shutting off the fuel.

Without going into detail the lever was subject to some force and so wondering if it might have rotated on the shaft.

Is this likely?

Are there any stops to limit rotation?

Yes, to a degree, but it depends upon the pump. there are earlier and later designs of the "turret" the stop and throttle are fixed to.

I think both types have a shaft with two flats so the lever can only fit in one position (although you could put the shaft 180 degrees out) so unless the retaining nut/screw came loose I can't see the lever moving on the shaft.

Usually the "turret" casting limits the stop lever movement with the newer pump being the more positive. The newer pump is the one with the Idle stabilisation damper in the top with the bleeds screw.

The more usual fault is the stop does not return to run fully so limits the movement of the governor valve giving a loss of maximum power and speed.

The inner end of the shaft has a machined flat to half the shaft thickness forming a crude cam that pushes the governor valve down to "no fuel" when operated so all IN all I don't see how what you describe could happen unless there is wear or damage to the "turret" or lever. All this presupposes its the usual hydraulic DPA pump and not the much rarer mechanical one.

If the stop shaft was fitted 180 degrees out then I think the engine would stop with the lever in the run position - that is if you got the shaft into the housing. but don't take the shaft out. Post a photo of the pump turret and lever indicating which way it is moved to stop.

 

[Boater Sam]

Stop cable not fully released.

[Mikexx]

3 hours ago, Tony Brooks said:

Post a photo of the pump turret and lever indicating which way it is moved to stop.

 

Many thanks for your ideas. I will post a photo as soon as I can. 

20 minutes ago, Boater Sam said:

Stop cable not fully released.

The cable is snapped. There is a short piece of cable still attached. In short, if anything, the lever is returning further back than before.

[Tony Brooks]

26 minutes ago, Boater Sam said:

Stop cable not fully released.

That was my first thought - so very common, especially when the outer clamp slips or there is not one. But the OP says the spring pulls the stop lever too far rather than not far enough. That is why I asked for a photo because it makes little sense to me.

I wonder if "the lever was subject to some force" really means the cable has seized and has been subject to some force.

Edited April 18, 2018 by Tony Brooks

[Boater Sam]

Surely there is a screw to adjust the idle speed on all versions of this pump? 

[Mikexx]

1 minute ago, Boater Sam said:

Surely there is a screw to adjust the idle speed on all versions of this pump? 

The idle speed is adjusted OK. 

The issue here is the fuel shut-off lever which is separate to the 'throttle' lever and idle/max speed adjusting screws.

[Tony Brooks]

1 minute ago, Boater Sam said:

Surely there is a screw to adjust the idle speed on all versions of this pump? 

Yes, early ones like a carburettor mixture screw and the later more common ones a long hexagon set screw but the OP is on about the stop lever not the throttle lever.

If the stop lever has not moved fully to "run" then it will cause loss of power and potential starting problems but the OP says it has moved too far rather than not far enough.

 

4 minutes ago, Mikexx said:

The idle speed is adjusted OK. 

The issue here is the fuel shut-off lever which is separate to the 'throttle' lever and idle/max speed adjusting screws.

The mention of a max speed screw more or less indicates its the more modern pump - unless its a mechanically governed one that there are a few about.

[Mikexx]

12 minutes ago, Tony Brooks said:

Yes, early ones like a carburettor mixture screw and the later more common ones a long hexagon set screw but the OP is on about the stop lever not the throttle lever.

If the stop lever has not moved fully to "run" then it will cause loss of power and potential starting problems but the OP says it has moved too far rather than not far enough.

 

The mention of a max speed screw more or less indicates its the more modern pump - unless its a mechanically governed one that there are a few about.

This is the hydraulically governed pump variety.

I'm aware that 90degs rotation makes the engine go from stop, to run, and then stop again.

I'm wondering if something inside could have sheared? Or should the lever be free to rotate? I will check this evening the extents of rotation.

[Tony Brooks]

Because the shape of the stop lever usually forms one half of the abutting movement stop I have never tried to rotate the stop lever through more than  the degrees allowed by the movement stops.

The image on page C5 here https://the-norfolk-broads.co.uk/downloads/bmc1500L-diesel-workshop-manual.pdf

Suggests the stop works by lifting the governor valve rather than pushing it down. It lifts against what could fairly be described as a "thin flat washer" so I suppose that washer might get bent enough to allow the shaf to move through 360 degrees. But if so I don't think it should affect the starting, I think it would more likely prevent it stopping.

The governor valve is made from steel so at this time of year I wonder if it stopped with a water droplet in the valve so it corroded up over the winter. That would make it difficult for the stop to lift the valve and it may allow the valve to jamb in the stop position wherever the lever is set. This is not a firm diagnosis, just trying to make the given facts make some sense.

 

Edited April 18, 2018 by Tony Brooks

[Mikexx]

I think this shows one of the stops on the casting has broken off and missing.

I have a spare pump and the casting associated with the throttle and stop lever is different. I was thinking of swapping these bits over from the spare but the alternative pump has spline headed bolts for which I have no socket.

[Tony Brooks]

Ignoring the fact that it should be done in clean conditions (a pump room) yes you could with a fair chance of success but you may need a new gasket or O ring for the turret to body seal. Those spline drive screws are often not that tight so may come out with pliers. A motor factors may sell suitable sockets individually.

[Chop!]

Does it not sound like simple problem with the engine stop?

Fit a new cable with a good return spring to the nearest sticky out bit!

Edited April 19, 2018 by Chop!

[Mikexx]

54 minutes ago, Chop! said:

Does it not sound like simple problem with the engine stop?

Fit a new cable with a good return spring to the nearest sticky out bit!

 

The current return spring returns (shown unhooked in the photo) rotates the lever too far, and actually shuts off the fuel. There is only a limited rotation where the shut-off mechanism allows fuel flow.

If I moved the other end of spring upwards, the idea might work, such at max pull the lever is the run position.

[Tony Brooks]

Why not fabricate a stop and fix it to the bolt that holds the return fuel pipe flange onto the pump body?

[Ray T]

As a temp'y job when my stop solenoid malfunctioned I fitted a "T" pull. Instead of a spring to pull the handle back I fitted some shock cord. Still there four years later and working well. The shock cord can be re tensioned as and when needs be.

https://www.ebay.co.uk/itm/Fire-Extinguisher-Master-Switch-3-7M-12ft-Pull-Cable-With-Red-T-Handle/332425401602?hash=item4d66191502:g:UeMAAOSwax5YsFp0

The engine is a Lister LPWS3

Edited April 19, 2018 by Ray T

[Mikexx]

On 18/04/2018 at 00:24, Mikexx said:

Hmm, if you remove the engine, its a very good idea to remove the cable attached to the lever!

 

I think that would be the preferred and safest way forward.

It looks a straightforward solution as access is pretty good from above.

Thanks.

[Mikexx]

On 19/04/2018 at 20:25, Mikexx said:

 

I think that would be the preferred and safest way forward.

It looks a straightforward solution as access is pretty good from above.

Thanks.

Strange, I thought I had replied to Tony's post "Why not fabricate a stop and fix it to the bolt that holds the return fuel pipe flange onto the pump body?" and not to my own!

In the end I was reluctant to use the bolt Tony intended as this seemed a little delicate and the bolt wasn't overly long and into aluminium. It was also not in line with the lever. So I used a pump bolt and it seems to limit movement rather nicely with a bracket I bent up and drilled.

 

[Tony Brooks]

looks good ad a nice cheap result.