Lister LPWS3 fuel system bleeding

[colmac]

Hi

Am about to change the fuel filter cartridges on my Lister LPWS 3. is anyone aware of any problems or can anyone offer any advice on bleeding the system thereafter ? Thank you

[Tony Brooks]

I thought that they were self bleeding as long as the starter battery is in good order.

 

I am sure someone will be along soon to confirm or deny.

 

 

Make sure you fill the new cartridge with CLEAN fuel before fitting, saves having to pump so much through the system.

Edited September 27, 2013 by Tony Brooks

[PhilR]

I thought that they were self bleeding as long as the starter battery is in good order.

 

I am sure someone will be along soon to confirm or deny.

 

 

Make sure you fill the new cartridge with CLEAN fuel before fitting, saves having to pump so much through the system.

 

There may be bleed screws on top of the filter housing, but otherwise as Tony said, the engine should be self bleeding. If your installation has pre-filters and aglomerators/sedimentors they too will probably have bleed screws but you should not need to open these to change the final filter. But it is a simple task and you are unlikely to need to loosen any pipe unions etc.

[colmac]

Many thanks for the replies so far. It would be good if the engine is self-bleeding. I have looked in the manual and it outlines the procedure for bleeding the system on completion of a filter change so I am in a bit of a quandary now. Hopefully I may get a conclusive answer.

[Tony Brooks]

Actually I would always manually bleed a self bleeding engine with a mechanical lift pump if it was possible because it reduces wear and tear on the starter and battery. It is also good to know how to do it ready for when you need to diagnose a fuel problem.

 

If you have any water traps before the lift pump I would drain and clean them and change any filters they use. Turn the fuel tap off first and with a bit of luck fuel will stay in the pipe from the tank. When done turn the tap on and open the bleed screw and see if air is being expelled. If not give the fuel tank breather a blow to push fuel from the tank into the pipes.. If air is coming out just wait until air free fuel flows out.

 

Then its use the lift pump priming lever to bleed the main filter, then the injector pump low pressure side. well over 50% of the time the engine will then run. If not repeat to be sure no air is left in the system, loosen all the main injector unions about half a turn and crank the engine. As each union drips lock it up and the engine should start.

 

No or a few wisps of smoke form the exhaust = no fuel (so in your case probably air in the system). Loads of smoke = another problem.

[FadeToScarlet]

On my LPWS4 (the only time, so far, of changing the filter) I used a sheet of silver foil bent into a scoop shape to catch the diesel as it came out of the filter when I unscrewed it.

 

Then, having filled the new filter with the diesel from the old filter, it was a simple matter of opening the bleed screw on the top of the housing, pumping the lift pump until the diesel came out in a stream with no air, and then tightening that and starting the engine. It cranked for slightly longer than normal- about 6 seconds- then fired.

 

Having had a BMC 1.8 on the old boat, it was really surprisingly easy.

Edited September 27, 2013 by FadeToScarlet

[Tony Brooks]

Then, having filled the new filter with the diesel from the old filter.

 

Now that was why I put CLEAN in capitals.

 

Filters store whatever they have caught in the bottom and fuel filters do not have anti-drain down valves so there is no knowing what you put in the new filter. I suppose putting may be 1/2 to 2/3 of what is in the old filter into the new would be OK most of the time but the rest should go into an old ice cream container type thing for close inspection for bug, water and hose degradation debris etc.

 

Personally I would fill with new diesel.

[colmac]

Have just spoken to the chappie who does the mechanical stuff at the basin mere we moor in Stourport. He says, from experience, the Lister doesn't need to be bled after filter change; just make sure the fuel cut off is "off", fill the new filter with clean fuel, replace filter and start engine ( having opened fuel valve ) I am going to give this a try so, once again, thank you very much for all your replies. It proves what a valuable tool these forums are.

[martyn 1]

Correct procedure to replace a fuel filter on an LPW or LPWS is as below. Assuming the system isn't completely dry (e.g. new engine or run out of fuel)

 

1. remove old filter.

2. dispose of old filter and all the fuel etc that is in it. (best practice) As Tony has said the filter is there to catch rubbish in the fuel so pouring the fuel and whatever is caught in your old filter into the new is not good practice.

3. fit new filter.

3. open vent on top of filter housing.

4. pump priming lever until clean fuel flows from the vent.

5. close vent.

6. Start engine as this should be all that is needed.

 

There are a few more steps if the system is completely dry. But get the procedure right and it will start straight away with no extra cranking. I have rebuilt hundreds of them over the years and run through the priming sequence properly from empty and they will do about 1/2 turns before starting.

[colmac]

Many thanks for that Martyn, very succinct and obviously written with the benefit of experience. I will do this next week after we have finished painting her bottom.

[PhilR]

Correct procedure to replace a fuel filter on an LPW or LPWS is as below. Assuming the system isn't completely dry (e.g. new engine or run out of fuel)

 

1. remove old filter.

2. dispose of old filter and all the fuel etc that is in it. (best practice) As Tony has said the filter is there to catch rubbish in the fuel so pouring the fuel and whatever is caught in your old filter into the new is not good practice.

3. fit new filter.

3. open vent on top of filter housing.

4. pump priming lever until clean fuel flows from the vent.

5. close vent.

6. Start engine as this should be all that is needed.

 

There are a few more steps if the system is completely dry. But get the procedure right and it will start straight away with no extra cranking. I have rebuilt hundreds of them over the years and run through the priming sequence properly from empty and they will do about 1/2 turns before starting.

 

That is really good advice, but can I add a couple of steps which should cover most fuel supply arrangements and maybe prevent fuel loss and back syphoning in some cases:

1. Shut the fuel cock near/at bottom of the fuel tank.

2. remove old filter.

3. dispose of old filter and all the fuel etc that is in it. (best practice) As Tony has said the filter is there to catch rubbish in the fuel so pouring the fuel and whatever is caught in your old filter into the new is not good practice.

4. fit new filter.

5. turn on fuel cock.

6. open vent on top of filter housing.

7. pump priming lever until clean fuel flows from the vent.

8. close vent.

9. Start engine as this should be all that is needed.

[martyn 1]

 

That is really good advice, but can I add a couple of steps which should cover most fuel supply arrangements and maybe prevent fuel loss and back syphoning in some cases:

1. Shut the fuel cock near/at bottom of the fuel tank.

2. remove old filter.

3. dispose of old filter and all the fuel etc that is in it. (best practice) As Tony has said the filter is there to catch rubbish in the fuel so pouring the fuel and whatever is caught in your old filter into the new is not good practice.

4. fit new filter.

5. turn on fuel cock.

6. open vent on top of filter housing.

7. pump priming lever until clean fuel flows from the vent.

8. close vent.

9. Start engine as this should be all that is needed.

 

Good bit of adding as I had forgot about any shutoff that may be off engine. technically shouldn't be needed as the fuel lift pump has a none return in it. but nothing to say that it works properly. So yes if valve fitted close it as added above.

 

Also a quick extra add to point 7, above. If the pump doesn't appear to be priming turn the engine over by hand a little as the engine has most likely stop with the pump on the top of the cam and therefore wont pump by hand.

[Ray T]

This has information on bleeding the system. Also very useful to have as it is the Lister Petter Workshop Manual:

 

http://www.set-zeise.de/UserFiles/File/LP%20Workshop%20Manual%20part%20I.pdf

[jonathanA]

think its all been covered but just to add...

 

when I change the filter on my LPSW4 I never fill the new filter with diesel - just how would I do that ? Practically its not terribly easy to do so i don't bother just means I have to operate the lift pump lever a few more times I suppose but it doesn't take a much anyway.

 

There is also a gauze filter on the lift pump - very easy to get at - undo the bolt on top and take the cover off, inspect/clean the gauze filter and replace cover and bolt.

[colmac]

Many thanks to all who offered advice. Have just changed the filter using the system as set out by Martyn1 in comment 11. Worked a treat and my wee Lister is chugging along just fine. Another job carried out and an experience tucked away for the future.

[twelveeyedfish]

Hello,

 

nice to be able to resurrect an existing thread that answers my question! so thanks. However it didn't work so I get to carry on a bit!

 

I have an LPW2 engine on which I recently changed the fuel filter and now I have done this, I cannot get the dratted thing to start. The fuel filter is primed but owing to a misunderstanding with a piece of dirt, air got in.

 

The manual is pretty clear about how to prime the system as are the guides above - all systems go, operate the lift pump a few times and away! I have operated the lift pump a few hundred times and I can't see anything spewing out anywhere, especially air! Even with the fuel connection to the injector removed, nothing is coming out. Unfortunately, this also seems to be the case whilst the engine is turning.

 

Does anyone have any thoughts or can they point out the thing I might be missing. Maybe the fuel pump is kaput, though the engine was running before I started this operation! I'm pretty confident with these things but I wont undermine the experience of you lot who also have them! Maybe it was just the draw of the engine that was pulling in fuel previously, aiding a weak pump.

 

Thanks!

[bizzard]

Hello,

 

nice to be able to resurrect an existing thread that answers my question! so thanks. However it didn't work so I get to carry on a bit!

 

I have an LPW2 engine on which I recently changed the fuel filter and now I have done this, I cannot get the dratted thing to start. The fuel filter is primed but owing to a misunderstanding with a piece of dirt, air got in.

 

The manual is pretty clear about how to prime the system as are the guides above - all systems go, operate the lift pump a few times and away! I have operated the lift pump a few hundred times and I can't see anything spewing out anywhere, especially air! Even with the fuel connection to the injector removed, nothing is coming out. Unfortunately, this also seems to be the case whilst the engine is turning.

 

Does anyone have any thoughts or can they point out the thing I might be missing. Maybe the fuel pump is kaput, though the engine was running before I started this operation! I'm pretty confident with these things but I wont undermine the experience of you lot who also have them! Maybe it was just the draw of the engine that was pulling in fuel previously, aiding a weak pump.

 

Thanks

The lift pump lever which is worked by a cam in the engine needs to be on the back of the cam before the hand lever works properly. If the lever is on the cams apex or close to it the hand lever will not work. Try turning the engine around by hand by 1/4 turns until the hand lever has a sort of spongy resistance feeling to it, it will probably make a nice sqwarking noise too. Slacken bleeder or inlet pipe on the engines fuel filter and pump the lift pump by hand, fuel should squirt out quite strongly. Tighten bleeder or pipe. Slacken off injector main fuel inlet pipes and turn engine over on the starter, when squirts of fuel should come out from them. When that happens tighten them up and the engine should start.

Edited November 28, 2016 by bizzard

[twelveeyedfish]

Thanks Blizzard, I'll give that a go. I didn't think there was much resistance to my finger on the lift pump. Knowing that a good squirt should come out certainly helps with the diagnosis. I wasn't too sure on the quantities involved. I did wonder if I wasn't catching something when pressing the lift pump lever though.

 

I'm a shade confused by your suggestion to remove the inlet or bleeder on the fuel filter - if I do that then the fuel will just squirt out strongly by the force of gravity (this happens, it's how I primed the fuel filter). The fuel pump is after the filter.

[bizzard]

Thanks Blizzard, I'll give that a go. I didn't think there was much resistance to my finger on the lift pump. Knowing that a good squirt should come out certainly helps with the diagnosis. I wasn't too sure on the quantities involved. I did wonder if I wasn't catching something when pressing the lift pump lever though.

 

I'm a shade confused by your suggestion to remove the inlet or bleeder on the fuel filter - if I do that then the fuel will just squirt out strongly by the force of gravity (this happens, it's how I primed the fuel filter). The fuel pump is after the filter.

I meant the fuel filter on the engine between the fuel lift pump and the injector pumps, not the filter between fuel tank and lift pump.

[twelveeyedfish]

Oh... there isn't one! Nor is there space to put one. There's just the standard fuel filter which is normally mounted on the engine but is mounted elsewhere on my boat just for fun! It goes fuel pump -> regulator -> injector. That's what all the diagrams say too. That's why I had originally disconnected at the injector itself to see if I could see fuel spewing out.

[bizzard]

Oh... there isn't one! Nor is there space to put one. There's just the standard fuel filter which is normally mounted on the engine but is mounted elsewhere on my boat just for fun! It goes fuel pump -> regulator -> injector. That's what all the diagrams say too. That's why I had originally disconnected at the injector itself to see if I could see fuel spewing out.

It is absolutely crucial that the engines micro filter unit is connected between the fuel lift pump outlet port and the fuel injector pumps or regulator to injector pumps.

Edited November 28, 2016 by bizzard

[twelveeyedfish]

Having looked into it a little further since you originally raised the point, this doesn't appear to be specified for an LPW2 engine. But now I come to write this I'm not sure I gave that level of detail originally. I can't see it as a serviceable item in the manual. Not to appear as if I am arguing. I am just at work rather than in front of an engine! I have seen small (tiny) paper filters on some other more modern engines however. I am guessing this is what you mean. The pipework on the LPW between the regulator mechanism to the injectors is rigid.

 

So... perhaps the on board filter system is fuel, fuel pump, filter, regulator injector? Even then however, the fuel filter will be a standard oil filter sized affair (as although it's not fitted to the engine mount, it is the same housing attached elsewhere).

 

Oh, the mysteries!

[bizzard]

It is absolutely crucial that the engines micro filter unit is connected between the fuel lift pump outlet port and the fuel injector pumps or regulator to injector pumps.

The one you say that is normally mounted on the engine does sound like its connected correctly, if its connected between lift pump outlet port and fuel injector pump regulator.

[twelveeyedfish]

Well my Blizzardino friend, after trawling through a bunch of photos and exploded diagrams, you're right! There should be a fuel filter exactly where you say. And there isn't! So, that issue aside, which I will resolve... in due course! I'm going to have to track down part numbers and new pipeworkage.

 

Thanks to your confidence building however, the engine runs! Nothing you said really helped because nothing was really wrong. But I did as you suggested and unplugged the pipes at each level. In reality however, the fuel just splurged through anyway - but you might expect that from a diaphragm fuel pump perhaps. I presume the non-return valve is really the stop solenoid... (there's definitely nothing missing except the fuel filter). I'm also not massively confident that one of the injectors is receiving fuel, but it's late and dark so I will reserve judgement!

 

It sounds like, although this engine will run on and on regardless right now, I might need to sit down and have a pint with someone who knows about these old fashioned engines and how they work. Thanks for your comments throughout the day. Much appreciated.

[RLWP]

Well my Blizzardino friend, after trawling through a bunch of photos and exploded diagrams, you're right! There should be a fuel filter exactly where you say. And there isn't! So, that issue aside, which I will resolve... in due course! I'm going to have to track down part numbers and new pipeworkage.

 

Have you got the build number for your engine? It's the last two digits in the serial number

 

Richard

Edited November 29, 2016 by RLWP