Non starting BMC 1.5 engine

[Cattleya]

I have not had much luck this year with my boat, firstly I had a new gearbox fitted over winter and huge expense (ended up costing £3000 fitting plus £1000 for the gearbox). Then I had a problem with diesel bug blocking my filters. Just when I thought everything was working I have another problem.

 

My engine won't start.

 

It turns over and makes noises like it's attempting to start. So far I have flattened the battery three times trying to start it. At first I thought maybe I had air in my fuel. I have bled and re bled my fuel system (at the fuel filter, injector pump and injector ends of pipes). I have fuel coming out of the pipes just before the injectors. I have smoke (grey/black) coming out of the exhaust when I crank the engine. I have power getting to my glow plugs (have only swapped one over, but have a whole set of new plugs to try). I left a heater running in the engine bay for about 20 minutes in the hope of warming the air/engine, this didn't work either.

 

Last time I had the engine running I had cleaned the gauze filter on the lift pump, I had to bleed the system to get the engine going. It ran fine, turnned it off and it restared straight away. Left the boat for about 3 weeks and now it won't start.

 

It has been suggested I should try some Easy Start, but I heard a lot of bad things about it.

 

Any other ideas before I end up spending even more money getting the marina engineers to look at it?

 

In the past the engine has started without the glow plugs, so I'm not sure they are the problem.

[Serendipity]

I'd give it a sniff of EasyStart to get it started and ensure it's running OK and can be normally re-started when warm.

 

When my BMC sounds like it's trying to start but won't, it's time to take out the glow plugs, and drill out all the coke that's formed in the glow plug ways and is preventing the heat getting through. If your's regularly starts without glow plugs though........

[Bones]

I'd give it a sniff of EasyStart to get it started and ensure it's running OK and can be normally re-started when warm.

 

When my BMC sounds like it's trying to start but won't, it's time to take out the glow plugs, and drill out all the coke that's formed in the glow plug ways and is preventing the heat getting through. If your's regularly starts without glow plugs though........

 

Not sure about the easy start.

 

Have you made sure that your stop cable is in the right position? Don't rely on the cable, push the bit on the injector pump until it wont move any further and make sure it doesn't spring back.

[larkshall]

I'm not familiar with your lift pump arrangement, but I would start there. I suspect that air has got in during the 3 week period you have left the boat and you have what amounts to an airlock.

 

I would crack the output union a tad, crank the engine to ensure diesel is coming out ok, and then tighten whilst engine is turning. Its the most obvious thing to do. If it is ok it will eject fuel immediately. If this pump is based upon the cam driven BMC pump, either diaphragm is naff or dirt has got into the so called non return valve.

 

Easy/Quickstart I would use it sparingly whilst cranking to see if the motor coughs and splutters.

 

In this weather you should not need glowplugs to start.

 

Oh if pump test fails to produce a good flow, then you probably got another attack of 'bug', or some other blockage.

[Serendipity]

Not sure about the easy start.

 

Have you made sure that your stop cable is in the right position? Don't rely on the cable, push the bit on the injector pump until it wont move any further and make sure it doesn't spring back.

 

Good point re the stop comment.

 

Easy Start is OK for 1) occasional use, 2) don't go spraying a long burst whilst trying to start. That's why I said a sniff of it. When I use it it's a half second burst in the direction of the intake, then turn it over.

[Cattleya]

I checked the stop lever at the engine end. That was fine.

 

 

If I had an air lock I presume i wouldn't be getting the fuel at the injector ends of the pipes or the smoking exhaust? When I opened the bleed scrrew on the injector pump I had a very good spurt of diesel coming out, enough for it to squirt a foot across the bilge.

[Bones]

I checked the stop lever at the engine end. That was fine.

 

 

If I had an air lock I presume i wouldn't be getting the fuel at the injector ends of the pipes or the smoking exhaust? When I opened the bleed scrrew on the injector pump I had a very good spurt of diesel coming out, enough for it to squirt a foot across the bilge.

 

strangely enough my BMC is playing up. I pumped the fuel pump as I turned the engine over incase there wasn't enough fuel getting through, and it seemed to make it start... and it still does... Black magic, but it might be worth trying. Make sure you listen to the engine though. When the engine seemed to be catching I stopped pumping and if it started seeming like it wasn't I started pumping....

[John Orentas]

I checked the stop lever at the engine end. That was fine.

 

 

If I had an air lock I presume i wouldn't be getting the fuel at the injector ends of the pipes or the smoking exhaust? When I opened the bleed scrrew on the injector pump I had a very good spurt of diesel coming out, enough for it to squirt a foot across the bilge.

 

 

When bleeding particularly the low pressure side of the system a 'very good spurt of diesel' is not enough, you need a good uninterrupted flow of fuel.. When attempting to start the engine many people give up too soon, diesels are unlike petrol engines in many ways, keep the engine turning for a good 20 seconds, more if the engine is trying, the engine needs to generate it's own internal heat..

 

Another good tip; Fit an 'override' push button so that the heater plugs stay energised during cranking, so many installations switch off the plugs when the starter runs.

 

A good condition fully charged battery is of course a must.

Edited July 22, 2008 by John Orentas

[larkshall]

I checked the stop lever at the engine end. That was fine.

 

 

If I had an air lock I presume i wouldn't be getting the fuel at the injector ends of the pipes or the smoking exhaust? When I opened the bleed scrrew on the injector pump I had a very good spurt of diesel coming out, enough for it to squirt a foot across the bilge.

 

 

In that case not lift pump.

 

One other dirty trick, if the engine is well used... Remove injectorss, or indeed heaters. squirt one shot of engine oil into each bore (from an oil can about 5ccs), replace everything and attempt to start. If it generally huffs and puffs and starts albeit with a fight, then its compression problem....

(This is a very old trick to compensate for suspected poor compression, have had to use this trick at sea in a force 8 gale)

 

As someone else has said it might be worth de-coking heaters, but these shouldn't be in use above about 7-9c.

 

I'm right in assuming there are no fancy start/stop solenoids?

[Cattleya]

I'm right in assuming there are no fancy start/stop solenoids?

 

That's correct. The BMC is a very basic engine. The stop lever pulls on a cable.

 

Any battery experts here? I have a 100 amp hour starter battery. It came with the boat so is at least 4 years old. I can crank the engine for about six 15 to 20 second attempts before the battery dies on me. I thought a 100 amp battery supplies 100 amps for one hour? I'm not sure how much power is used starting the engine, but I expect it should give me more starting power than that? I'm wondering if maybe the engine isn't spinning fast enought to start.

[alan_fincher]

If the engine has been marinised by someone like Calcutt, and uses their "standard" or "deluxe" control panels, then I believe the heaters will be kept running as you tun the key that extra click to crank the engine.

 

It's certainly how it is on mine, and is an unmodified arrangement with a standard Lucas key-switch.

 

I don't actually agree about not using the heaters at higher ambient temperatures. The BMC engine manual firmly states that they should always be used for "between 15 and 30 seconds".

 

The other thing is you are clearly told to set the throttle to fully open, and although people say that's irrelevant, that's what the manufacturer says.

 

These engines do have a mind of their own. I never skimp with the heaters when cold starting, as it often struggles to start if you do, even on a hot day.

 

But then I can attempt to bleed the fuel system, with two injector pipes broken open, on a cold day, and the bugger starts and runs on 2 cylinders.

 

In my experience, if you have the nuts loosened at the injectors, and fuel is spurting out freely as you crank, then that's the fuel side covered.

[Alistair]

If I had an air lock I presume i wouldn't be getting the fuel at the injector ends of the pipes or the smoking exhaust? When I opened the bleed scrrew on the injector pump I had a very good spurt of diesel coming out, enough for it to squirt a foot across the bilge.

 

Bleed the system up to all four injectors: while cranking the engine, slacken and re-tighten the unions one at a time.

 

You sound like you're nearly there - let us know how it goes!

 

oh PS I've got a BMC 1.5 in my boat in Oxford. PM me (anybody reading this, natch) if you'd like to service it before we go to Cropredy...

[John Orentas]

But treat the low and high pressure sides as if they were independent systems (which indeed they are) don't do anything with the high pressure system until you are totally satisfied that the low pressure side is fully bled.

[alan_fincher]

Any battery experts here? I have a 100 amp hour starter battery. It came with the boat so is at least 4 years old. I can crank the engine for about six 15 to 20 second attempts before the battery dies on me. I thought a 100 amp battery supplies 100 amps for one hour? I'm not sure how much power is used starting the engine, but I expect it should give me more starting power than that? I'm wondering if maybe the engine isn't spinning fast enought to start.

Missed this first time through.

 

A 100 amp hour battery (new) may well be capable of delivering 1 amp for 100 hours, but certainly incapable of delivering 100 amps for 1 hour.

 

Difficult science, but fact.

 

It's likely you are taking well in excess of 100 amps anyway, when cranking the engine.

 

Six bursts of 20 seconds, (so about 2 minutes) cranking doesn't sound a lot though. If not totally knackered, I'd say you battery is well on the way.

 

Are you aware it's turning over slower than you are used to ? Usually if they'll turn over reasonably fast, even if slower than usual, they will fire eventually.

 

(I'm shortly off to the boat to dismantle some of my fuel system, which will require a re-bleed - I hope I'm not posting similar stories of woe in two or 3 hours time!)

[John Orentas]

Alan.

 

Try and measure your cranking current while you are there !

[alan_fincher]

Alan.

 

Try and measure your cranking current while you are there !

I know where you are coming from John, but I don't have the technology.

 

Not that I have one, but I do believe Snibble's explanation why measuring with a clamp meter isn't reliable.

 

The best number I have seen came from Allan Jones' work on BSP 's engine, where IIRC, a shunt ammeter, (part of a battery monitor?), measured the starting current accurately.

 

146 amps was the number I remember, for what is thought to be a very easy cranking engine. Unless my compression is more knackered than I hope it is, I would anticipate I'm using at least that, (plus well in excess of an extra 30 amps running the heaters).

[RobinJ]

It turns over and makes noises like it's attempting to start. So far I have flattened the battery three times trying to start it. At first I thought maybe I had air in my fuel. I have bled and re bled my fuel system (at the fuel filter, injector pump and injector ends of pipes). I have fuel coming out of the pipes just before the injectors. I have smoke (grey/black) coming out of the exhaust when I crank the engine. I have power getting to my glow plugs (have only swapped one over, but have a whole set of new plugs to try). I left a heater running in the engine bay for about 20 minutes in the hope of warming the air/engine, this didn't work either.

 

Last time I had the engine running I had cleaned the gauze filter on the lift pump, I had to bleed the system to get the engine going. It ran fine, turnned it off and it restared straight away. Left the boat for about 3 weeks and now it won't start.

Three basic reasons why a BMC won't start, 1) Fuel, 2) Air, 3) Heat.

If you have had the lift pump apart to clean the filter, it is possible that it is sucking air. I always start by cracking the return conection on the filter or one of the injectors and using the lever on the lift pump to prime the system. If you are getting a free flow of fuel and none is coming out of the lift pump then it is unlikely to be sucking air!

The next stage is to make sure the main injector pump is primed by checking the bleed screw on the pump body, depending on the type of pump, the engine may have to be turned over to do this.

Finally check that fuel is getting to each injector!

The heater plugs can be simply checked by turning them on (with a cold engine) and making sure each one is warm to touch afterwards. You can tell a lot by removing the heaters (soot, fuel etc.), but you can also tell if you have a sticking valve by removing them and turning the engine over by hand, they should each blow in turn!

A 110Ah battery will turn over a BMC (20-30 seconds at a go) for at least 6 attempts, it will depend on how long you wait between each attempt as to how many goes you get (I think its something to do with plate saturation?), as the battery recovers slightly the slower it is discharged. Even turned over slowly it should still fire!

[Serendipity]

These engines do have a mind of their own. I never skimp with the heaters when cold starting, as it often struggles to start if you do, even on a hot day.

 

Mine doesn't start the day summer or winter without heat, but once run to temperature it'll start without heat anytime during the rest of the day. I don't think I'm the only BMC owner who finds that?

[Bones]

something else to check, is that the control lever, when pushed forward, actually DOES move the lever on the injector so fuel IS getting through....

[RLWP]

Then I had a problem with diesel bug blocking my filters.

 

It turns over and makes noises like it's attempting to start.

 

I have fuel coming out of the pipes just before the injectors.

 

I have smoke (grey/black) coming out of the exhaust when I crank the engine.

 

Last time I had the engine running I had cleaned the gauze filter on the lift pump, I had to bleed the system to get the engine going.

 

It ran fine, turned it off and it restarted straight away. Left the boat for about 3 weeks and now it won't start.

 

Just picking out some of the things from your original posting. How frustrating!

 

Are you sure that there isn't still diesel bug debris in your fuel tank that has blocked your filter again?

 

You say you have fuel coming from the injector pipes and grey smoke and an engine that is trying to start. In fact it did run three weeks ago.

 

Do you now get white smoke (unburned fuel) from your exhaust as the engine tries to start?

 

Oh, and not missing a chance to state the bleedin obvious, is your fuel tap on? Or in gear with a carpet wrapped around the prop?

 

Richard

 

Bemused....

Edited July 22, 2008 by RLWP

[LEO]

Hi,

 

I had this problem on my 1.5 on a couple of occassions, if the system has been bled satisfactorily (can take a while to get a good spurt through), a well charged battery, full throttle, 60+ seconds on the heater plugs and perhaps a quick spurt of 'easy start' got it going. Easy start was only used sparingly.

 

Shall be interested to here of the outcome.

 

But your battery does need to be in good condition to get the engine turning over quickly.

 

The gearbox renewal seems a full price, was it a straight swop?, because I have changed a Hurth box over on the canal side in 3 hours.

 

Albi.

[Bones]

Hi,

 

 

The gearbox renewal seems a full price, was it a straight swop?, because I have changed a Hurth box over on the canal side in 3 hours.

Albi.

I thought that too! I bought mine reconditioned and it only took a couple of hours to put it back on, and take the old one off, it just bolts on.

[Yamanx]

You may have bled all the air out, but how is the water seperated?

 

If you have an inline seperator, then clean it out, particularly if you have the dreaded black sludge. When I had it bad I had to change the filter every couple of hours!!

 

Also bleading the fuel sytem at the injectors may not blead the aire up to the pump. On the side of the pump there is a blead screw this needs to have a steady stream of fuel, and to check everything is right use the hand crank on the lift pump to blead it this far. You can use the engine starters to blead it at the injectors afterwards.

 

Small use of easy start is fine, just dont run the engine on it.

[LEO]

Hi Bones -

 

Typical woman - 'Anything you can do, I can etc, etc!'........

 

 

Albi.

[Bones]

Leo - outside NOW, start without me...