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Nestor Espinoza

BMC hard to start, could it be the timing?

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Hello,

 

I have a boat with a BMC 1.5 in decent nick that until a couple of days ago started up every time. Then I had to fix a diesel leak, got that sorted, but it didn't want to start again. The leak was the return pipe from the injection pump to the filter, i didn't mess with the high pressure side, but did a whole leak check anyway, pump check, and bled the system until I saw diesel coming out of the injector pipes.

 

Still no luck, so I tried Easy Start, and after a lot of persuasion the engine started, belching smoke obviously, maybe I flooded it a bit, but it was soon running fine. I stopped it and tried again, and the same thing happened, it only started with a lot of easy start, then it was fine.

 

I am thinking that maybe the timing is off? So that diesel comes in too late? If that is the case, in which direction do I turn the pump? It seems to be almost all the way counterclockwise, so I really can only move it clockwise.

 

Any ideas?

 

Thanks a lot,

 

Nestor

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Are you giving Glo plugs enough time to heat up ?

Are the glo plug galleries clear of carbon build up ?

Are the glo plugs working ?

Its pretty cold now and going to get colder.

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Many others who are far more knowledgable than I will come in on this but I must ask the question, WHY do you suspect the timing? If you did'nt touch it there's no reason for it to have changed. Having had had a 1.5 and now having a 1.8 I'm far more inclined to suspect it's air in the fuel system or maybe the heaters.

 

 

Frank

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While it's cranking and before it fires, is there any white smoke?

Once it's running, is there much smoke? If so what colour?

If you turn off while the engine is warm and restart, does it require lots of cranking or does it fire instantly?

 

If you get great clouds of white smoke while cranking, suspect the glow plugs aren't working properly and look at the electrical circuit to each of them. With the ignition switched to pre-heat, check you get 12 volts at each plug.

If you don't get much smoke while cranking, suspect a fuel supply issue, either an air leak or drain back.

 

HTH

 

Rob

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Sounds like it is something you messed with.

Probably not the breakers or spark plugs.

Is fuel valve fully open?

No air leaks in fuel line - filter - pump?

glow plugs?

Is the return line open all the way back to tank?

crank speed? -battery voltage.

is the stop fully in, when in.

is there a cold start option on the pump?

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I have to go with others who have said that if you haven't touched the timing or the high compression side of the pump then it is highly highly unlikely to be the timing. I have 2 of these engines. One on my boat and a spare. My spare I have stripped down and rebuilt at least twice and whilst I do have problems with it it does start without any problem. Similarly the engine on my boat starts without any problems. But the one on my boat did have a problem and that was caused by air getting into the fuel lines. It took me ages to find the leak and in fact I didn't really find it I ended up cutting back all the pipes at the joints and changing all the olives in the couplers and that must have cured the leak. Where ever the leak was it certainly wasn't visible to me but it let enough air into the diesel lines to prevent my engine from starting. I am also told that air can leak in without any diesel leaking out which I suppose is logical if you think about it. BMCs can be a bit of a pig to bleed properly. There are some YouTube videos done by Wilton Marina about various servicing aspects of the BMC 1.5 and they are very good. Perhaps have a look at those and try again.

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Sounds like it is something you messed with.

Probably not the breakers or spark plugs.

Is fuel valve fully open?

No air leaks in fuel line - filter - pump?

glow plugs?

Is the return line open all the way back to tank?

crank speed? -battery voltage.

is the stop fully in, when in.

is there a cold start option on the pump?

 

I thought only Kelvins had spark plugsbiggrin.png

  • Greenie 1

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With bleeding maybe broke the feed line or connection off the glowplugs ?

second maybe the little hole in the fuel filter is blocked with some dirt , Its in side the connection from the return pipe from the DPA pump on the fuel filter.

Edited by Dutchie

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Wow, thanks a lot for all the responses, I'll try to answer all the questions.

 

-Glow plugs seem to work, at least they draw current, some 30A. I have never inspected them, someone mentioned carbon deposits, I'll see if I can clean that. How long should I keep them on before cranking? Someone told me 30 seconds some time ago.

-A mysterious air leak sounds plausible. However, I undid all the joints and checked that diesel was flowing through all of them.

-I suspected the timing might have been off before, this is on a friend's boat and when comparing her engine with mine it feels sluggish. If I throttle mine in neutral it revs up right away, while hers takes its time. When that happens with petrol engines you need to advance the timing a bit, is it the same with diesels?

-When the engine starts it always smokes A LOT for a few seconds, white smoke. Then it settles and emits some blueish smoke which almost disappears as the engine warms up.

-After all the cranking the battery was very low.

 

In the end I ran the engine for a couple of hours, stopped it and after a couple of hours it started fine, with full cranking power. Let's see what happens tomorrow.

 

Now is it possible to flood a diesel? Say you crank it many times and it doesn't start, diesel does not evaporate like petrol. I read somewhere that if after the third try a diesel doesn't start you should wait at least 15 min, is there any logic in that?

 

In my boat I made a contraption that sprays easy start into the engine and it is controlled from a button in the dashboard. I never bother with the glow plugs, I just spray a bit and the engine starts at the first crank, every time. Not very elegant, but the £4 can lasts almost one year and kinda postpones a needed overhaul. In my friend's boat I'd rather get things to work as they should.

 

Thanks again,

 

Nestor

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-When the engine starts it always smokes A LOT for a few seconds, white smoke. Then it settles and emits some blueish smoke which almost disappears as the engine warms up.

 

What's happening here is that some cylinders are firing and one or two are not. The white smoke is atomised but unburnt fuel. When it fires on all of them, you are getting blue smoke which is oil. This clears when the piston s warm up

 

Most BMC engines follow this pattern

 

If you choose to remove the heater plugs, be very careful - they are easy to break

 

Richard

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Wow, thanks a lot for all the responses, I'll try to answer all the questions.

 

-Glow plugs seem to work, at least they draw current, some 30A. I have never inspected them, someone mentioned carbon deposits, I'll see if I can clean that. How long should I keep them on before cranking? Someone told me 30 seconds some time ago.

-A mysterious air leak sounds plausible. However, I undid all the joints and checked that diesel was flowing through all of them.

-I suspected the timing might have been off before, this is on a friend's boat and when comparing her engine with mine it feels sluggish. If I throttle mine in neutral it revs up right away, while hers takes its time. When that happens with petrol engines you need to advance the timing a bit, is it the same with diesels?

-When the engine starts it always smokes A LOT for a few seconds, white smoke. Then it settles and emits some blueish smoke which almost disappears as the engine warms up.

-After all the cranking the battery was very low.

 

In the end I ran the engine for a couple of hours, stopped it and after a couple of hours it started fine, with full cranking power. Let's see what happens tomorrow.

 

Now is it possible to flood a diesel? Say you crank it many times and it doesn't start, diesel does not evaporate like petrol. I read somewhere that if after the third try a diesel doesn't start you should wait at least 15 min, is there any logic in that?

 

In my boat I made a contraption that sprays easy start into the engine and it is controlled from a button in the dashboard. I never bother with the glow plugs, I just spray a bit and the engine starts at the first crank, every time. Not very elegant, but the £4 can lasts almost one year and kinda postpones a needed overhaul. In my friend's boat I'd rather get things to work as they should.

 

Thanks again,

 

Nestor

Yep so did I, numerous times over the course of a week or so until I decided to bite the bullet and renew all the joints in the fuel line. Be careful with that easy start stuff as well. I have never used it on my engines but I am told that it can do damage to diesel engines.

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Engines can get addicted to easy start, cant they?

I believe it is the owners that get addicted and keep using it

 

Richard

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Model aircraft diesel engines run- ran on ether, a mixture of ether and caster oil, used to mix our own but can't remember the ratio.

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Engines can get addicted to easy start, cant they?

A myth; engines that need easy-start are probably already well worn and lacking compression. OTOH, a short squirt (< 1 sec.) could get your engine started in sub-zero tempertures with a poor battery.

 

Alan

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To add to Alan's post. If too much is used it can ignite when the piston is still a fair way from TDC and stop the engine dead. The very high pressure can then snap piston rings and lands.

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Model aircraft diesel engines run- ran on ether, a mixture of ether and caster oil, used to mix our own but can't remember the ratio.

I used to use :- 1/3 Ether, 1/3 SAE 30 oil, 1/3 Paraffin. High performance engines used to like as dash of Amyl Nitrate.

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Model aircraft diesel engines run- ran on ether, a mixture of ether and caster oil, used to mix our own but can't remember the ratio.

If I remember correctly it was 1/3 parafinn, 1/3 either and 1/3 engine oil (it may have been caster oil). To make the 'super' version you added a dash of Amyl Nitrate (spelling?) This last ingrediant is, I believe, now a class 1 drug. As a 13 year old I could walk into my local Boots chemist and buy it without question. Amazing.

 

 

Frank

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