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jonesthenuke

3LW Uneven Running

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I would appreciate some advice from the Gardner experts....

 

We have a 3LW which starts and runs OK. It does not smoke, just a grey haze when cold and the exhaust is near transparent when the engine has warmed up.  The engine appears to have plenty of power, though I have no experience of any other 3LW in a narrowboat to compare it to.

 

However, the engine runs unevenly, by which I mean it appears to be working much less on cylinder 1 (furthest from the flywheel). The exhaust manifold is always cooler on that cylinder. Also, if I operate the levers on the injection pump one at a time, cutting out cylinder 1 does not affect the engine anywhere near as much as cylinder 2 or 3. This behaviour is consistent; it does  not change with engine temperature etc.I have changed the sprayers for reconditioned ones but this has made no difference.

 

I am thinking that the injection pump needs attention, however, is there anything I should check first?

 

If the consensus is that the pump needs attention, what is the best way to get this done? Assuming I send the pump to be overhauled, how straightforward is it to refit and get the timing right? (I am an engineer with a reasonable level of practical skills, its just that I have never timed a diesel before).

 

We moor the boat in Kinver. Is there anyone relatively local (e.g Birmingham area) that I could get to look at the engine or to service the pump?

 

Thanks

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The flange mounted pumps are not to hard to remove and refit. Can you tell if:

 

all the plungers are moving about the same amount;

 

are you getting internal diesel leaks;

 

are the individual pump elements timed properly (your manual will help you)

 

Richard

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8 hours ago, RLWP said:

The flange mounted pumps are not to hard to remove and refit. Can you tell if:

 

all the plungers are moving about the same amount;

 

are you getting internal diesel leaks;

 

are the individual pump elements timed properly (your manual will help you)

 

Richard

Richard. I will check the plunger movements later today. Are you suggesting visually checking with engine running or by turning it over by hand?

 

I have seen no sign of diesel in the lube oil if that is what you mean.

 

On the timing checks I'll have to dig out the manual.

 

What is the best way to do a compression test?

 

 

Thanks

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Plunger movement through the little windows on the side of the pump, turning the engine by hand

 

Diesel leak: Good - that suggests the pump elements are tight in the body

 

No idea on compression. Your engine doesn't have heater plugs so there is no simple tapping point. I made a dummy injector to do a compression test on a 2L2

 

Richard

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Do the easy stuff first. First use the priming levers to check the injectors all make  squeak or grunt when the lever is pulled quickly. Check they all have a similar resistance, ie take the same effort to operate. Do this with each fuel pump tappet in turn at the bottom of its stroke. Check tappet clearance and decompresor shaft adjustment on no 1 cyl. Remove flywheel inspection cover and check timing lines align with the scribed lines in the little Windows on the pump. It does sound as if no. 1 cyl is getting little or no fuel. It's not smoking badly so compression is good. If no1 fuel pump lever is easier to operate than the others, check the delivery valve spring is ok. 

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Sounds to me that you have a fuelling problem, if the compression was low on cylinder one but fuelling all good then you would expect smoke from that cylinder. I would suspect pump output, fuel pressure or phasing.

 

The pump output could be a dodgy delivery valve or just wear on the element.

 

Cylinder one is normally the furthest from the fuel input to pump so lack of fuel is one possibility if the fuel pressure is low,filters blocked, if the engine is an amal pump one then is the bypass clear?

 

With the phasing possibility dont assume that the lines in the windows lining up means its correct. If the pump has been overhauled in its life and has had the pump tappets faced, then doing the phasing as Gardner state in the manuals with the shim usually ends up with it being miles out from one cylinder to the next. If you use the lines and the tappets have been faced then the the relationship between cam and pump has been altered and your phasing will be out. You will sometime see pumps stamped -3 -4 -1 etc next to each element, this relates to the amount it needs altering to get the phasing correct.

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When Paul Gardner's overhauled my pump top they erased the old lines and scribed New ones. The sprayers were numbered to each cylinder and the output balanced on the gardner machine. Maybe some pump shops aren't so particular. 

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Thanks for all the replies. I will not get the opportunity to check further as I will be working away from the boat for a while.

 

I will have a go at making a compression tester as I have a junk sprayer body so will use it to make an adaptor. Whilst the consensus seems to be that its a fuelling issue, having a compression tester available may be useful in the future.

 

Regarding some of the questions that have been posed, yes its an AMAL lift pump. There seems to be no issue with the other cylinders so I assume pump pressure is OK. On the issue of the bypass line , I assume this is the return line from the fuel filter? if so there is one, I will check to see if that has flow. There is no bypass from the injection pump.

 

The injection pump levers seem to have similar resistance and travel.

 

There are no markings on the pump other than a "K".  According to the pump label, it is the original pump for the engine, though I suppose the label could have been swapped at some time.

 

Finally, who would you recommend to carry out a pump overhaul as that seem to be the way this is going.?

 

Thanks again for the help.

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Should you decide to remove the pump, the ease or not of refitting it depends on a couple of things, how much room do you have in front of the engine, you need to be able to remove the timing chain cover and be able to see the marks on the gears to get the initial gear mesh position right setting, I have had to do it using a mirror on at least 2 engines. Secondly do you have good access to the timing marks on the flywheel and do they match the setting for the speed at which the pump has been set?.

I am just 5 miles away in Stourbridge and i can check out your pump (depending on when you want to do it).

My number is in the front of the G.E.F newsletter or PM me if you would like me to look at it for you.

 

Steve

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15 minutes ago, Split Pin said:

Should you decide to remove the pump, the ease or not of refitting it depends on a couple of things, how much room do you have in front of the engine, you need to be able to remove the timing chain cover and be able to see the marks on the gears to get the initial gear mesh position right setting, I have had to do it using a mirror on at least 2 engines. Secondly do you have good access to the timing marks on the flywheel and do they match the setting for the speed at which the pump has been set?.

I am just 5 miles away in Stourbridge and i can check out your pump (depending on when you want to do it).

My number is in the front of the G.E.F newsletter or PM me if you would like me to look at it for you.

 

Steve

Thanks Steve, have PMd you.

I think the timing cover will come off, I will check tomorrow. may need the alternators removing to get space but that is easy

The pump is marked for 1500RPM, not sure what is marked on the flywheel, again I will check tomorrow.

 

 

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3 hours ago, jonesthenuke said:

Finally, who would you recommend to carry out a pump overhaul as that seem to be the way this is going.?

 

Thanks again for the help.

We can get CAV BPF pumps overhauled

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14 hours ago, jonesthenuke said:

Regarding some of the questions that have been posed, yes its an AMAL lift pump. There seems to be no issue with the other cylinders so I assume pump pressure is OK. On the issue of the bypass line , I assume this is the return line from the fuel filter? if so there is one, I will check to see if that has flow. There is no bypass from the injection pump. 

The reason its relevant if its an Amal pump engine is that the fuel filter assembly is different from a gravity one. On non lift pump engines the feed and return sides of the castings are separate on the filter assembly for a Amal pumped engine there is a tiny hole between the two which essentially maintains the fuel pressure at a sensible level(the amal pump is capable of shifting alot more fuel than the engine needs) If this hole is not there or is blocked it can cause all kinds of rough running issues. Just a thought.

 

And yes I meant the return from the filter assembly as on a gravity engine with good injectors you should have very little or no flow from it but on a amal pump engine with the hole mentioned above in place there should be a good constant flow.

 

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In my experience if the bleed hole in the filter housing becomes blocked on lift pump engines, then the fuel gets aerated and after around 20 mins or so of running the engine cuts out and the pump need to be bleed before it will run again.

 

Steve

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On ‎10‎/‎05‎/‎2018 at 10:42, martyn 1 said:

The reason its relevant if its an Amal pump engine is that the fuel filter assembly is different from a gravity one. On non lift pump engines the feed and return sides of the castings are separate on the filter assembly for a Amal pumped engine there is a tiny hole between the two which essentially maintains the fuel pressure at a sensible level(the amal pump is capable of shifting alot more fuel than the engine needs) If this hole is not there or is blocked it can cause all kinds of rough running issues. Just a thought.

 

And yes I meant the return from the filter assembly as on a gravity engine with good injectors you should have very little or no flow from it but on a amal pump engine with the hole mentioned above in place there should be a good constant flow.

 

I have much the same issue as this with my 3LW. It's been sitting there for about 8 months since last being run in the workshop. I now have the fuel supply, starter, alternator and coolant all sorted, but like the OP here, the engine is running, but it's reluctant to rev smoothly and generally sounds lumpy, as if it's only running properly on two. I've seen other 3LW owners balance a 50p piece on top of the tappet cover. My engine is shaking the entire boat, which can't be right!

I'm pretty sure I've managed to bleed the fuel successfully, but is it worth going as far as removing the sprayers to check, bearing in mind my mechanical knowledge is somewhat limited.

Exhaust is similar to the OP's - slight white haze, no smell of diesel. I have an Amal lift pump, so will try to check what Martyn suggests.

 

Thanks in advance for any help you can give.

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If it was running fine and now isn't its unlikely to be the hole i previously mentioned unless some crap has blocked it,

 

It sounds to me like its probably not running on a cylinder properly. if one cylinder isn't bled and is airlocked the engine will run rough with no smoke as its not injecting at all.

 

I would suggest first with the engine stopped but in the cold start position on the injection pump pulling the priming levers one by one until it goes firm and a squeak is heard from the injector, you may have to turn the engine over a bit by hand to be able to do this to all the cylinders (if the pump is already at the top moving the lever does nothing..)

 

Alternatively if you struggle to hear the squeak or your not sure if you can or not, you can remove the rocker cover and slacken the injector pipe nut a turn or two and pull the levers as before, when you see fuel coming out around the nut re tighten it and do on the rest. when finished clean up an fuel and refit the cover. 

 

Then give it a go and hopefully all is well, if not pull the levers hard one by one with the engine running and hold it firmly down, with each one you should hear a noticeable change in  engine note and if setup properly this should be balanced across all the cylinders. if one make a lot more difference than the others, or one doesnt seem to make hardly any difference at all then its not setup properly.

 

Hope this helps and isnt too confusing. 

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You dont need to hear.even if you are stone deaf,just "feel"the pipe with the engine running.........preferably on a bend,where the pulse is stronger.......I recently had a problem with a 4LW,where the lifter in the Gardner part of the cambox was stuck  partially,preventing full injection.......when I fiddled with it,the lifter stuck fast,and took a bit to free............the cause in my case being water /rainwater entering thru the little port...........I managed to free it without dismantling the pump...........by the not recomended method of removing the delivery valve ,and driving the whole lot down.............DONT do this if you have shaky hands or no spare pump bits...................you should also be aware injector line leaks inside the rocker cover may wreck the motor if neglected.

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On 10/05/2018 at 11:42, martyn 1 said:

The reason its relevant if its an Amal pump engine is that the fuel filter assembly is different from a gravity one. On non lift pump engines the feed and return sides of the castings are separate on the filter assembly for a Amal pumped engine there is a tiny hole between the two which essentially maintains the fuel pressure at a sensible level(the amal pump is capable of shifting alot more fuel than the engine needs) If this hole is not there or is blocked it can cause all kinds of rough running issues. Just a thought.

 

And yes I meant the return from the filter assembly as on a gravity engine with good injectors you should have very little or no flow from it but on a amal pump engine with the hole mentioned above in place there should be a good constant flow.

 

Where exactly is this “ tiny hole”.?

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15 hours ago, jenevers said:

Where exactly is this “ tiny hole”.?

the hole is at the bottom of the hole in the centre under the yellow arrow.  The bottom of the hole is conical left from when it was drilled and at the centre point is the tiny hole (if you have one). It connects the yellow return drilling to the red filter to injector pump side drilling and essential maintains the fuel pressure at what it should be. This is only relevant if you have a lift pump, if you engine is gravity feed it doesn't need it.

IMG_1178.JPG

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1 hour ago, martyn 1 said:

the hole is at the bottom of the hole in the centre under the yellow arrow.  The bottom of the hole is conical left from when it was drilled and at the centre point is the tiny hole (if you have one). It connects the yellow return drilling to the red filter to injector pump side drilling and essential maintains the fuel pressure at what it should be. This is only relevant if you have a lift pump, if you engine is gravity feed it doesn't need it.

IMG_1178.JPG

Hi thanks for the diagram. Can't actually see the hole in the photo., But I'll look for this next time I'm aboard. My 4LW has an Amal pump.

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The small drilled hole (green dots) in the pic is the air bleed ,for a gravity tank ,there is a fitting with a thumbscrew to bleed the system after a filter change,with the Amal lift pump,there is a plug in the small threaded hole at top,and any air is continuously bled away into the return pipe to the tank.....So after a filter change ,initial bleeding is by pumping the lever on the Amal.......the green dotted drilling must be clear for both systems,or air cannot be vented................with a diesel ,fuel pressure is not critical,but must be high enough to feed the injector pump reliably.

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You would need to undo the pipe that exits left on the photograph and remove the adaptor union from the filter housing, the hole is then at the bottom of the tapped hole.The hole is 0.018" or 0.457mm in diameter so is not so easy to see.

An easier way to check it is to remove the pipe and operate the lift pump manually fuel should flow out of the hole.

In my experience if the hole is blocked then the engine will run for a short period then dies as the fuel has become aireated and the pump then needs bleeding again, so if your enine is running happily then its doubtfull that you have a problem

Edited by Split Pin

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Not quite as much Brasso applied to your engine as the one in the pic.............you would know if the bleed was blocked  when you changed the small filter ........

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1 hour ago, Split Pin said:

You would need to undo the pipe that exits left on the photograph and remove the adaptor union from the filter housing, the hole is then at the bottom of the tapped hole.The hole is 0.018" or 0.457mm in diameter so is not so easy to see.

An easier way to check it is to remove the pipe and operate the lift pump manually fuel should flow out of the hole.

In my experience if the hole is blocked then the engine will run for a short period then dies as the fuel has become aireated and the pump then needs bleeding again, so if your enine is running happily then its doubtfull that you have a problem

I was only asking out of curiosity. My engine runs just fine, smoke free and the exhaust note is fab.?

 

51 minutes ago, john.k said:

Not quite as much Brasso applied to your engine as the one in the pic.............you would know if the bleed was blocked  when you changed the small filter ........

No Brasso whatsoever. 

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