BMC 1.5 question

[stephenlloyd]

Hi all, sorry if this has already been covered, but I can't find a specific reference to it here.
I have recently bought a yacht with a BMC 1.5 in it, that has never been able to start without assistance from (not happy to admit it) 'easystart'.

Once running it will keep going until I kill it with the standard pull cable. She doesn't sound great, partly I suspect because the air filter is almost destroyed.
Anyway, so to the point, we delivered the yacht 140 miles to where we live, (motor sailed) and the engine was great, not getting very hot etc. But...it did smoke (white) all the way.
About 4 miles from our harbour it basically lost revs and died, and refused to start again. Dirty fuel is the suspicion.

So I changed the fuel filters, (and the water trap/fuel filter housing as it had an air leak) and after eventually bleeding her successfully, she started, once again with easystart. And ran until I killed her, (still smoking white)
I have de-coked the plugs, and tested them, they all glow red hot.
My question is, what is the white smoke most likely from? Can diesel bug cause it? Or is it likely the injectors not spraying properly, or something more sinister, head gasket?
We put fresh fuel (about 180 litres) in the tanks before the delivery, but there was probably about 20 litres of pretty old fuel in there before, so could that be an issue?

Ok......thank you to anyone who has managed to read through this far! Basically, what next? She turns over without firing at all, until easystart is used. And I know its terrible to use, and have only used it a couple times, to check if she will run at all. And want to avoid it until I have an idea why she won't start on her own. I usually glow her for ages before even trying too.

Should I attempt getting the injectors out and have them reconditioned?

Alright, please feel free to ask me to clarify anything, and any suggestions please help!

Thanks very much!

Steve

 

[chas]

I have had a similar problem with my Thorneycroft T90 (same engine). It turned out to be a tiny fuel leak in the high pressure fuel pump. Your engine sounds as if it has not had much TLC. It might be a good idea to find your local CAV service place and take the HP pump and injectors there for a service. I did that a couple of years ago and it made a fantastic difference.

 

[kalindi]

Wellcome to the forum and membership of the BMC club. I too have recently purchased a yacht with a BMC1.5 engine and am having some difficulties so perhaps we could share experiences in the future. If there is fuel and the glow plugs are working but the engine refuses to start I would expect unfortunately there to be a problem with compression. Other than testing this may be identified as a lack of power. I am not sure about the white smoke but are you sure it is smoke or could it be steam? This could be caused by a poor flow of cooling water getting to the exhaust injection and turning to steam, perhaps check the impellor etc. I am sure more knowledgable recommendations will be forthcoming so good luck.

 

[ianat182]

Do you make sure that the pull cable is pushed back after stopping the engine as this may prevent the initial 'choking' for the first firing and your glowplug has nothing to atomise. I'd also check the raw water inlet for partial blockage of weed or growth particularly if the inlet has the grill type filter on it.
My old engine did not like motor-sailing on the starboard tack with any heel on the boat,as the inlet was on the starboard side and only just below the waterline so broke the surface occasionally I believe.

 

[penfold]

White smoke can be caused by cooling water leakage or fuel injection timing/duration problems. As has been suggested already, get the injectors and the pump fettled by a local specialist, and a compression test is advisable; you should be looking for something over 250psi with a spread of no more than 20psi.

If compression is down, you can test if it is a valve seat problem or a piston/bore wear problem by squirting a small quantity(1cc) of oil into the injector hole before fitting the compression tester. If the reading goes up, you have bore wear. If there's no change it's the valves.

 

[toad]

I seem to remember that the BMC engine was the one that the glow plug holes got coked up on. The glow plug holes tended to fill with coke so even when the plugs were working no heat got to the engine. The fix was to get a drill of the right size, ground off the point and coat it with grease then screw it into each hole by hand to remove the carbon which then sticks to the grease.

 

[kalindi]

Toad is quite right about the problem of carbon in the glow plug chamber. I have the manual which gives the right drill size but I think that it is on the boat. If you need it I can email it to you this coming weekend

 

[DownWest]

Not sure I follow that. The BMC 1.5 used the Ricardo Comet design of combustion chamber in the cylinder head where both injector and glow plug shared the space. To coke up the plug would mean blocking of the combustion space. I stripped a couple in the past, and found no sign of this.
My vote is for injection or steam. If fuel, it will smell unburned?

 

[stephenlloyd]

Answers

Hi all, and thanks for the input,
I have decoked the plugs, and yes they were completely coked up. 4.3 mm drill bit twisted with fingers only in the reccommendation I followed.
Didn't realise blocked raw water intake/faulty impeller could be causing the smoke.
I just thought because it wasn't firing, possibly faulty injectors not misting properly would cause this, and the, because they aren't working properly, ie dribbling fuel instead of spraying, there is excess fuel that is being burnt off as white smoke?
Now I guess it could be one of many.
So where to next?
Do I get the injectors serviced, or have a compression test? Which will tell me more, and in what order?
I'll have a look at the impeller later today and let you know how it goes.

THANKS AGAIN FOR ALL THE IMPUT!!!
Please keep it coming!
Regards
Steve
P.S. Downwest, I haven't smelled the smoke/steam yet, but will also do that next time I run her, just avoiding running her as much as possible to avoid the dreaded easystart!

 

[maxi77]

Re: Answers

As far as I am aware the needs a lot of glow plug when starting from cold, mine takes a good 15 to 20 seconds but then usually starts without any further assistance.

 

[VictorII]

Re: Answers

I was advised by the former owner to heat the glow plugs for 40 seconds when cold and 10-20 when the engine has been running already. Never had any problems with 500 engine hours up till now.

 

[DownWest]

Re: Answers

Sounds like I might have been wrong about the coking. Worn or dribbling injectors will give you black smoke. Timing out gives white smoke (forget why /forums/images/graemlins/confused.gif)
A

 

[Heckler]

Wonderful thing this forum BUT you get all sorts of well meaning advice and guesses, and there there is a lot of guesses. Go back to basics, if you are using easy start you are suffering from lo compression. The first thing you want to do is check the compression, then if/when it is confirmed then go to the next step, what is causing the lo compression? What does the exhaust smell of? Is it burning engine oil? did it use much on your journey? The bollox of what colour is the exhaust gives a definitive answer as to what is wrong is wrong, white smoke can be burning lube oil, it can be a duff injector/s pouring neat diesel in to the cylinders and it only part combusting, it can be steam, but again that should be obvious depending on experience.
You know what you have to do, go and do it!!
/forums/images/graemlins/smile.gif
Stu

 

[fisherman]

Might be an idea to avoid using easy start. Until you find the root of the problem, to get it going use a gas blowtorch in the air intake. I sold a truck with a BMC 1.5 which I could never start easily. New owner had no trouble, he just put a bloody big battery on it.

 

[DownWest]

Well, at least these guesses are free!

Re. Fisherman's truck and big battery. A friend visited recently and was using easystart for his LDV with a Ford DI engine. Suspected the starter motor and exchanged it-Result. The solenoide had dodgy terminals, causing resistance and slow turnover.
A

 

[Heckler]

Re: Answers

If you have to use something to start her, give it a good blast of wd40, its kinder to the engine, the propellant and the white spirit dont "explode" as quickly as ether and dont shock load the rings and piston lands. It is the shock which squeezes the ring lands on to the rings and stops them expanding to seal or even breaks the rings.
Stu

 

[Heckler]

Guesses are ok but send peeps off on the wrong track, methodical trouble shooting is the way to go. In this case the use of easy start fixes the prob, easy start works when the compression is bad, notice that he said once running its ok ish except for white smoke, white smoke caused by, oil burning, dribbly injectors, or water. oil burning caused by worn bores, dribbly injectors will cause bad starting but will make the engine misfire on start up, no mention of that, if the white smoke is water vapour I doubt if it would have brought him 140 miles and still be running! therefore logical to check for poor compression first. Easy init?
Stu

 

[searover2]

Just to throw one in the works , a guy here has been using easystart in his engine for 20 yrs he tells me, he never has had glow plugs connected. when i said to him that easystart will damage your engine, he just looked at me with a daft ezpresion, and said well it hasnt done any harm in twenty years, so i smiled and made my exit

 

[Bilgediver]

He has probably learnt from experience how to give it just the right whiff....However in less experienced hands it can be leathal to the engine as the slightest excess causes combustion pressures far in excess of design and on some engines can result in broken rings as well as stretched head studs.. Especially if the user is over enthusiastic and thinks more is better.