Beta 20 Diesel Bleed problem

Seagreen

Seagreen

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So hello everyone.
I have a 'bleeding' problem with the aforesaid Beta 20. The engine is about 10 years old, but has run faultlessly up till now. The sequence of events:
Yard removes tank, to do some work. Yard monkey replaces tank, but mixing the Outflow and Return pipes up. (Yes, that happened -but he's a shipwright not an engineer)

Tank fuel system is bled through by me. No problems.
Engine starts fine, runs fine, until Fuel starvation kicks in. Engine stops.
Examine system, re-attach fuel pipes correctly. Semi-bleed system.
Engine fires very roughly, then refuses.

Despite strenuous attempts at re-bleeding, including priming the fuel line with Diesel, engine just splutters on start and fails to fire.
Fuel at CAV filter, Fuel at Lift pump bleed screw, froth or nothing at Second Fuel filter, but fuel at Injector block bleed screw, but suspect no fuel at Injector Nuts.

So my question is - can this be anything other than just an irritating airlock problem in the fuel supply? Would removing the Top Fuel Oil filter be necessary? Is there a solenoid for the lift pump that may just have decided to die at a really inconvenient moment?

I'm open to any suggestions.
TIA.
 
Last edited:
Seagreen said:
Fuel at Lift pump bleed screw, froth or nothing at Second Fuel filter,
Is there a solenoid for the lift pump that may just have decided to die at a really inconvenient moment?
I'm one to any suggestions.
TIA.
Click to expand...
I wasn't aware of a lift pump bleed screw, isn't that one and the same as the bleed screw on the engine mounted filter?
If you're getting froth from that bleed point, I think that trying to start the engine is doomed to failure,
The manual lift pump has a very small delivery per stroke, lots of waggles of the lever needed.
It has only a very small suction capability, 25 cm according to Beta, make sure that the tank is well filled, or pressurise as suggested.
There is no solenoid unless an electric pump is fitted, but make sure the stop solenoid is not stuck in.
If the boat is in the water, close the cooling seacock if cranking lots!
 
Seagreen said:
So hello everyone.
I have a 'bleeding' problem with the aforesaid Beta 20. The engine is about 10 years old, but has run faultlessly up till now. The sequence of events:
Yard removes tank, to do some work. Yard monkey replaces tank, but mixing the Outflow and Return pipes up. (Yes, that happened -but he's a shipwright not an engineer)

Tank fuel system is bled through by me. No problems.
Engine starts fine, runs fine, until Fuel starvation kicks in. Engine stops.
Examine system, re-attach fuel pipes correctly. Semi-bleed system.
Engine fires very roughly, then refuses.

Despite strenuous attempts at re-bleeding, including priming the fuel line with Diesel, engine just splutters on start and fails to fire.
Fuel at CAV filter, Fuel at Lift pump bleed screw, froth or nothing at Second Fuel filter, but fuel at Injector block bleed screw, but suspect no fuel at Injector Nuts.

So my question is - can this be anything other than just an irritating airlock problem in the fuel supply? Would removing the Top Fuel Oil filter be necessary? Is there a solenoid for the lift pump that may just have decided to die at a really inconvenient moment?

I'm open to any suggestions.
TIA.
Click to expand...

Bleeding procedure is described in the owners manual. The lift pump is purely mechanical and you can operate it by hand to bleed the system but note what the manual says about the possibility of the engine having stopped with the pump on the toe of the cam lobe.


Dont keep cranking the engine with the cooling water seacock open or you may flood the exhaust with water and then get water back into the cylinders. Close the seacock but be ready to open it promptly when the engine starts.
 
Tank is above the engine, just. I've also serially adjusted the Injector Nuts to no real result. I'm thinking that there's an airlock somewhere. Forcing the fuel through is an option - at least, creating a far higher head for the diesel would be very easy.
 
This is wonderful engine but a bit of a pig when it needs bleeding after filter changes.

You just have to keep waggling the lift pump for ages - perhaps 15mins - if feels like you are achieving nothing but eventually you get to the point that the engine will start.

Then (remembering to turn seacock off) keep starting the engine.

I have found that it doesn't 'clear' itself well and the coughing, spluttering and cutting out keeps with it for quite a while. Certainly compared to Merc diesel (car) and Bukh 36 (boat) that I had run dry of fuel sorted themselves out instantly, the Beta 20 just does not sort itself out in 10 seconds. Might be 10 mins or even more.
 
Check fuel can return to tank if it can't it may be blocked a hose could have gotten twisted or damaged doughtfull but worth checking
Lift pump is simple enough just non return valves and diaphragm it's simple to check undo the fuel feed to lift pump to be sure there's fuel arriving then re tighten next undo the fuel line connection where it leaves the lift pump manually work the lever to check fuel is being pumped through. After that bleed filter head then injector pump finally crack an injector nut turn engine over it should fire tighten injector nut be sure to keep fingers away from injector as fuel pressure at around 15 bars will inject into your skin !
Don't crank the starter to long as it may over heat and cause more problems
 
Having had the tank replaced and piped up by someone that you cannot reply upon. I would:

1. Pump out the fuel into suitable vessel(s).
2. Remove pipes from the tank one at a time and check the tank connections are patent, maybe pushing a bit of wooden dowel through the tank union just to be sure.
3. Pay particular attention to the tank vent ( a blocked vent will allow the engine to start and run for a while and then starve the engine to a standstill).
4. Do not assume or take anything for granted.
5. Once you are satisfied with the tank check all hoses and pipework - be wary of old flexibles which can be worse on the inside than they may appear externally. Sometimes replacing old ones is best option.

Once you are confident the fuel supply system is patent and the tank is venting correctly - try again vent the system and try it. If the same problem exists you can concentrate on the next steps.

1. You are looking for opportunities for air to be sucked in through poor pipework joints on the pump suction side. Depending on your box of come in handy gear you could contrive to pressurise the suction side as a test for leaks. Bit of a faff but it will expose or reassure all is well.

2. Have you put clean fuel filters in? All buttoned up tight?

3. Still not successful ? Repair or refit the fuel lift pump (sometimes the repair kits are close to the cost of a complete pump).

I am sure you will get to the bottom of it.
 
Tank was thoroughly cleaned last July, and fuel filtered. I'm sure its either just me being a bit sloppy with my process, but since everything was fine, until it wasn't (isn't that always the way?) I'll follow the suggestions here and be a bit more thorough.
 
As others have said, make sure you have either removed the impeller or close the seacock till the engine fires. Failure to do this could result in water in the engine bores. Don't forget to reopen seacock once the engine fires or you will knacker the impeller.

When you are bleeding the injector pipes, you must have them cracked open just a little and you have to close them while the engine is cranking and fuel without any air is spurting out. If you just stop cranking and then nip the nut up, air may get back into the pipe. If you are on your own, you will have to rig up some way of cranking the engine while you are holding the spanner on the injector nut ready to close. Same goes for all of the connections, i.e. crank and nip up, next one, crank and nip up which should be done starting from the fuel delivery line.

On one engine I had problems with getting bled, I got plastic pipes which fitted over the ends of the injector pipes. I slackened the pipes at the fuel pump so that the pipes were clear of the injectors so that I could connect the plastic pipes. The open ends of the plastic pipes were pushed into a container. That way I could crank the engine and use the primer pump and clear the lines. Just have to ease the fuel pump end connections of the pipe just enough to rotate the pipes back into position.
 
Poecheng said:
... You just have to keep waggling the lift pump for ages - perhaps 15mins - if feels like you are achieving nothing but eventually you get to the point that the engine will start. ...
Click to expand...

Yes - and make sure your 'waggling' is actually pumping. When I first did it on my older but similar Beta, I recall thinking that the movement was pumping when it was in fact largely just taking up slack in the lever! If you've done it before that's probably not an issue, but a hard push - uncomfortable to the finger after a while - is needed.
 
Froth or nothing at any bleed point means there is still air in the system. You hàve to be systematic about bleeding, working through from the first bleed point, continuing at each one until no bubbles appearing the fuel before moving on to the next one. It's no good bleeding the injectors if there is still air in a filter.
 
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