1.5 stalls out quietly

[Lorien]

Hi,

Our 1.5 BMC has always ran ok.

To be fair despite the famous poor starting and smoke at a first dead stop it's always been reliable.

A couple of weeks ago the engine note changed slightly and very gracefully (at idle)all went quiet.

Hmmm.....strange.

Wierd but it restarted and was fine for a week or so.

Cruised through locks and pounds for a good few hours last weekend no problem. Stopped for water and after 10 minutes and very gently it stopped again at idle. Restarted ok and strange a few minutes it did it again.

Holding the revs up very slightly all was ok.

After mooring up I changed the fuel filter although it was nice and clean.

I bled the sediment pot and again loads of clean fuel ran out.

Two years ago it had the injection pump reconditioned.

Yesterday it ran charging batteries for two hours as it has again today. Now and again though we get a slight change in pitch and wonder if it's going to stop but so far it's kept going?

Anybody else had this problem, or symptoms?

 

Cheers,

Jim

[Lorien]

How very strange,

 

Just posted this problem and it cut out again!

 

Cheers,

Jim

[Dave Clinton]

Hi,

Our 1.5 BMC has always ran ok.

To be fair despite the famous poor starting and smoke at a first dead stop it's always been reliable.

A couple of weeks ago the engine note changed slightly and very gracefully (at idle)all went quiet.

Hmmm.....strange.

Wierd but it restarted and was fine for a week or so.

Cruised through locks and pounds for a good few hours last weekend no problem. Stopped for water and after 10 minutes and very gently it stopped again at idle. Restarted ok and strange a few minutes it did it again.

Holding the revs up very slightly all was ok.

After mooring up I changed the fuel filter although it was nice and clean.

I bled the sediment pot and again loads of clean fuel ran out.

Two years ago it had the injection pump reconditioned.

Yesterday it ran charging batteries for two hours as it has again today. Now and again though we get a slight change in pitch and wonder if it's going to stop but so far it's kept going?

Anybody else had this problem, or symptoms?

 

Cheers,

Jim

 

If there's no other symptoms I think you're already looking in the right place. Fuel.

 

Sounds like water to me. could you have filled with some dodgy fuel recently?

[ditchcrawler]

Sounds to me like a minor air leak, when its running fast there is enough diesel being pumped to self bleed it but then its strange you can restart it.

[OldGoat]

Umm -

Air leak - but that usually gives uneven running

Fuel pump (know about 1.5's ) but dose it have a diaphragm type? then-

Weak diaphragm,

worn pump arm / or bad springs on pump valves.

 

Hopefully somebody who knows about these will be along shortly........

[Alan Saunders]

Unless you can have an expert diesel engineer diagnose the problem on site you can only address the most likely problems. Quietly stalling on tickover suggests many possible causes as above. Not much else goes wrong with diesel engines except poor compression and that would usually result in 'hard starting', in winter temperatures, and excessive oil consumption.

 

Maybe you need to have the injectors serviced? Not cheap, maybe £25 a piece, but a good diesel service agent will report back the condition of the injectors, e.g. 'poor spray pattern' and return them 'as new'.

 

Meanwhile, ensure that the engine is idling at recommended rpm when hot, probably ~900 rpm. Some engines suffer oil starvation if idled at less than recommended rpm.

 

Alan

[Tony Brooks]

Yes the lift pump has a diaphragm but before even considering that I would check and clean the strainer that is usually under its domes cap. On no account remove the seal from the cap unless replacing it with a new one. They can swell so becoming impossible to put back in the cap.

 

Also (see Vetus thread) check the tank breather is free.

 

Worth trying to blow back into the tank, there might be a blocked strainer gauze on the tank pick up pipe.

 

Once you are sure the fuel system is not bocked start considering air leaks but when Hydraulic injector pumps run short of fuel they usually rev up and then stop. I see no mention of actually revving up.

[Lorien]

Hi,

Thanks for the help.

No revving to a stop definately.

The note of the engine in the boat goes a bit slower, you know then it's not happy.

Not long after it'll slow down and stop, it happens quite quickly.

Air would bring a none start, no bleeding is required it'll start up straight away.

 

It must be fuel issue of some sort. I've ruled out filter and sediment pot, maybe it's the fuel pump as mentioned.

 

I'd say also it's becoming more frequent, it all started as a one off, now it's every time or every other.

 

Thanks again,

Jim

[MtB]

My money is on water in the fuel, too.

 

Fuel starvation seems rather unlikely to me if the engine runs fine faster and fine at tickover most of the time too, yet stalls randomly at tickover.

 

 

MtB

[Mrs Tawny Owl]

My money is on water in the fuel, too.

 

Fuel starvation seems rather unlikely to me if the engine runs fine faster and fine at tickover most of the time too, yet stalls randomly at tickover.

 

 

MtB

How does it restart then if it is running on water?

 

I wonder how low the idle speed is set

 

Tony, could this be a stop lever spindle thing?

 

Richard

[Alan Saunders]

Yes the lift pump has a diaphragm but before even considering that I would check and clean the strainer that is usually under its domes cap. On no account remove the seal from the cap unless replacing it with a new one. They can swell so becoming impossible to put back in the cap.

 

Also (see Vetus thread) check the tank breather is free.

 

Worth trying to blow back into the tank, there might be a blocked strainer gauze on the tank pick up pipe.

 

Once you are sure the fuel system is not bocked start considering air leaks but when Hydraulic injector pumps run short of fuel they usually rev up and then stop. I see no mention of actually revving up.

I should have thought of a partially blocked tank breather as a possible cause. I have seen it a few times, in particular a Range Rover that drove well enough but stalled if left at idle for a while. The breather pipe had been crushed by previous accident damage. A faulty mechanical fuel lift pump could produce similar symptoms, pumping fast enough at higher RPM but failing to supply sufficient fuel at low RPM.

 

Alan

[Tony Brooks]

How does it restart then if it is running on water?

 

I wonder how low the idle speed is set

 

Tony, could this be a stop lever spindle thing?

 

Richard

 

The whole of the pump body is flooded with fuel at transfer pump pressure that is higher than lift pump pressure so I doubt its anything to do with the stop lever spindle - as long as the stop lever is fully in the run position when running.

 

I think rig a gravity tank feeding the fuel filter to rule out a faulty lift pump and once that is sorted I am leaning towards partial seizure but without temperature and oil pressure readings its all not much more than guesses.

 

The other thing is that this may be one of the few 1.5s with a mechanically governed injector pump (photo?) and those will just struggle a bit and die with fuel starvation.

[MtB]

How does it restart then if it is running on water?

 

 

I used to get this with Reginald. Be running fine then randomly either hesitate or completely stop, every hour or so. I syphoned out about five litres of gloopy watery crap from the day tank and it never did it again.

 

I think the water was just up to the take-off pipe and occasionally a droplet or two would flow down into the engine, stopping it or making it hesitate, so not running on water, but occasionally interrupted by water.

 

 

MtB

[Lorien]

Hi,

 

Things are getting real wierd!

 

Ran boat, had loads to do so was on for 2.5 hrs.

 

Then it started tapping quite loudly, then cut out.

 

I figured there wasn't too much to lose now so I started it later on.

It seemed ok??

 

Is it me or this is definately a fuel issue?

 

This has worsened over the week. Quite quick really.

 

Cheers,

Jim

[MtB]

Is it me or this is definately a fuel issue?

 

 

Groundhog day.

 

As far as I can see the consensus in the thread above is that it's a fuel problem. Have you actually read the answers so far?

[Tony Brooks]

Any chance of telling us the oil pressure and engine temperature when this "tapping" started?

 

I am still far from convinced its not seizing, so how long after it stops do you leave it before it will restarts and if you try immediately how fast does the starter spin the engine over? About normal or slower?

 

I am not saying its not a fuel issue but teaer in a hydraulic governor is more likely to gum it up and stop it working full stop - and it would normally have revved just before it stopped.

[Lorien]

Hi,

 

Mike, thanks for that. I get the general idea but please bear in

mind that I run a business as well as being a liveaboard. Time is not always on my side. I also have a family

which makes a situation I'm trying to resolve before it starts to have an impact

on them if things get worse.

 

Everbody has been very helpful, thank you I'm trying to eliminate

things as I go and as time allows.

 

I have an oil pressure guage tapped in, the only problem I have here is that

by the time I leg it as the boat falters, it stops. It reads zero by the time I get there.

However, every time this happens - it restarts. Today the engine was left for approx

2hrs before restarting. Again the annoyance is it seemed to run ok.

 

Temperature is normal, it runs at around 60-70 even on a hot day, same as when on the move.

At first I thought it was knocking but I'd describe it more as tapping. The revs did raise a little but

then it died down and stopped.

 

Cheers,

Jim

[David Mack]

I have an oil pressure guage tapped in, the only problem I have here is that

by the time I leg it as the boat falters, it stops. It reads zero by the time I get there.

 

What does the pressure gauge read

 

A ) immediately after starting the engine from cold?

 

B ) when the engine is running normally and has got up to temperature?

[MtB]

Hi,

 

Mike, thanks for that. I get the general idea but please bear in

mind that I run a business as well as being a liveaboard. Time is not always on my side. I also have a family

which makes a situation I'm trying to resolve before it starts to have an impact

on them if things get worse.

 

Well if you don't make time to work through the suggestions and questions asked of you, then it's unlikely to get fixed and its gonna impact on you harder!

 

 

 

I have an oil pressure guage tapped in, the only problem I have here is that

by the time I leg it as the boat falters, it stops. It reads zero by the time I get there.

However, every time this happens - it restarts. Today the engine was left for approx

2hrs before restarting. Again the annoyance is it seemed to run ok.

 

 

I think Tony is trying to establish if the engine turns over normally immediately after it has stalled. Try to re-start it immediately and tell the board if it turns over normally, or if it struggles to turn over. The answer will rule in or rule out a lot of stuff.

 

 

 

Temperature is normal, it runs at around 60-70 even on a hot day, same as when on the move.

At first I thought it was knocking but I'd describe it more as tapping. The revs did raise a little but

then it died down and stopped.

 

 

This suggests air getting in the fuel, after all...!

 

 

MtB

[Lorien]

Hi,

 

Quick update.

Today no tapping... but it didn't sound right after starting up and stalled out after 20 mins.

Started up again straight away this seems pretty consistent.

Other half ran it at a faster than tickover and it seems to have run ok from then on.

 

I will check out pressures over the weekend as we are moving. Hopefully I can shed more light on things, I hope......

 

Cheers, Jim

Edited May 29, 2015 by Lorien

[RLWP]

Any idea what your idling speed is?

 

Richard

[Tony Brooks]

I am tempted to raise the troll question but will give the OP the benefit of the doubt for now.

 

Questions have been asked to try to help us rule certain things out. The OP says they have run the engine again and restarted it but still fail to answer the specific questions.

 

I am afraid that keeping on repeating (in effect) what he said in his original post will not solve the problem and if they intend to cruise before sorting it to my mind it seems very stupid. The boat may breakdown and refuse to start miles away from anywhere.

 

I note that there is no evidence that the strainer that is in most of these lift pumps has been checked even though its only a few minutes job. This was mentioned a couple of days ago.

 

The rev up upon stalling mentioned a few posts ago is back pointing at fuel yet there appears to have been no attempt to rig a gravity test tank to rule out a lift pump fault.

 

I suppose I am getting old and grumpy.

[MtB]

I get the feeling the OP is genuine but not a technical person accustomed to attending to detail.

 

I think they are looking to the internet (and this forum in particular) for a magic bullet to fix the problem (e.g. flick this hidden switch), rather than painstakingly and time-consumingly follow detailed advice. The advice has turned out to be a lot more complicated than they were hoping!

[Dave Clinton]

ah, why didn't you say.....the magic switch is on the bottom of the engine, just out of reach on the far side. switch that and all will be well.

[MtB]

I think it's a lever, rather than a switch, on the BMC1.5.