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Bmc 1.5 won't start


Cpv1000

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Has anyone got an idea as too why my bmc 1.5 won't start , battery is fully charged and engine turns but won't fire, took an injector off turned engine over and only a dribble of diesel came out it wasn't a fine mist -spray. Is it a pump ?? 

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What colour smoke comes out of the exhaust when it turns over :

 

White

Blue

Black

Grey

 

Is it turning over 'fast enough', is it sluggish or 'wizzing' ?

 

Have you got enough fuel in the tank ?

 

Is the fuel filter clean ?

 

What voltage are the batteries showing when the starter is turning the engine over, and what voltage when not turning the engine over (not some Micky Mouse gauge, but measured with a multimeter at the battery terminals)

 

A diesel engine only needs 3 things to 'work'

Fuel

Air

Compression.

 

If you have compression then its either air or fuel :

 

Is the air cleaner / filter clean ? try taking the filter element out)

 

Is fuel getting to each stage of the fuel line :

Is fuel in the pipe as it leaves the tank ?
is fuel getting into the fuel filter ?

Is the fuel filter clean ?
Is fuel leaving the filter ?

Is fuel getting to the fuel pump ?

Is there a 'hidden' filter into, or close by, the pump ?

Is fuel being pumped out of the pump ?

Is fuel going into the injector pump ?

Is fuel coming out of the injector pump ?

Is fuel reaching the top of the injectors ?

Edited by Alan de Enfield
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2 minutes ago, Cpv1000 said:

Smoke  is white, tank full , battery fully charged, turns over fast , admittedly I've not checked fuel filter.

 

White smoke can be condensation, or unburnt fuel passing thru the system and into the exhaust, which means it isn't burning properly.

 

 

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2 hours ago, Cpv1000 said:

Has anyone got an idea as too why my bmc 1.5 won't start , battery is fully charged and engine turns but won't fire, took an injector off turned engine over and only a dribble of diesel came out it wasn't a fine mist -spray. Is it a pump ?? 

If the injector is dribbling and not spraying first check is to bleed the injection pump fully in accord with the manual. It will not start until you get a proper sharp spray. White smoke shows you are getting some fuel into the cylinders but a dribble will not burn.

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18 minutes ago, BEngo said:

Make sure the stop control is pushed fully home.  With the control partly put the pump will not deliver diesel to the injectors.

 

N

I always forget this as I am used to an electric valve on the pump rather than the cable. Excellent post.

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2 hours ago, Cpv1000 said:

Has anyone got an idea as too why my bmc 1.5 won't start , battery is fully charged and engine turns but won't fire, took an injector off turned engine over and only a dribble of diesel came out it wasn't a fine mist -spray. Is it a pump ?? 

 

Did you really remove an injector or did you just undo the feed to it?

  • Greenie 1
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4 minutes ago, Cpv1000 said:

What are the causes??

Just the feed but diesel was only dribbling 

 

You wont see a mist from inlet union on the injector.

 

There won't be a huge amount of fuel being delivered to the injector.

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1 minute ago, StephenA said:

 

You wont see a mist from inlet union on the injector.

 

There won't be a huge amount of fuel being delivered to the injector.

 

Exactly correct. Only a drip or dribble is normal. At full chat the delivery is less than a pinheads worth on each pulse. It needs the injector spring and nozzle valve to produce enough pressure to form a fine spray.

If you decide to take an injector out and invert it so you can reconnect the injector pipe and check the spray take great care to stay well away from the spray and NO naked lights.

  • Greenie 1
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7 hours ago, Alan de Enfield said:

 

White smoke can be condensation, or unburnt fuel passing thru the system and into the exhaust, which means it isn't burning properly.

 

 

 

A blowlamp up the air intake whilst trying to start it works wonders on a tired engine with poor compression.

 

Not if there is a paper air filter though! 

 

 

  • Haha 1
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8 hours ago, MtB said:

 

A blowlamp up the air intake whilst trying to start it works wonders on a tired engine with poor compression.

 

Not if there is a paper air filter though! 

 

 

 

And if it then starts it indicates poor compression as long as the glow plugs have been seen to be glowing red-hot. Low compression will allow the engine to spin over fast on the starter even with a battery with a lower than normally needed state of charge.

 

Warning. BMC 1.5 glow plugs often snap their tips off in the head if forced undone. They need worrying out. First tighten a little then loosen a similar amount and keep on like that undoing it a tiny amount more each time.

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46 minutes ago, Tony Brooks said:

And if it then starts it indicates poor compression as long as the glow plugs have been seen to be glowing red-hot.

 

 

Eh? Is there a way to see them glowing Tony?

 

I can only think of a derivative method, being to measure the current in the wire feeding each. If a glow plug is drawing 10A or 20A, it must be glowing red-hot.

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10 minutes ago, MtB said:

 

 

Eh? Is there a way to see them glowing Tony?

 

I can only think of a derivative method, being to measure the current in the wire feeding each. If a glow plug is drawing 10A or 20A, it must be glowing red-hot.

 

You take them out and energize them. I have had them only glowing close to the base of the pin with the tip only warm by conduction. I think those had probably shorted the heating element. On anything but a 1.5 I would suggest the easiest way is to take the plugs out but on a 1.5 the likelihood of the snapping complicates the decision, but we know  the 1.5s suffer difficult starting if the glow plug pin holes are not regularly cleaned of carbon so taking them out and then taking the opportunity to decarbonize the holes is arguably the better way.

 

If a pin does snap off experience tells me that they can be safely drilled out by using a hand or battery drill without dismantling the engine if the drill bit is kept clean and well greased.

 

The other problem with pinatux injectors (as used on the 1.5) is that the injector auxiliary spray holes tend to block up and that in turn makes cold starting more difficult so this might be a combination of things.

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17 hours ago, Cpv1000 said:

What are the causes??

Just the feed but diesel was only dribbling 

 

If the white exhaust "smoke" when cranking is more than a few wisps then that suggests fuel is being injected but not igniting and from that we can conclude either the air in the cylinder is not getting hot enough to ignite the fuel or the fuel droplets injected are too large to heat up and ignite in the time available.

 

Air not getting hot enough indicates lack of compression or the glow plugs not working.

The fuel droplet thing is caused by old, worn and partially clogged injectors.

 

The question for the OP is what is the most cost-effective way of deciding which of the above is the case.

 

As Mike suggested measuring the current flowing to each individual glow plug is a very good but not 100% indication that the glow-plug is working. This means the OP needs either a clamp type DC ammeter or an ammeter for direct connection that can read up to 100 amps because we don't know the current each plug will draw nowadays. Some draw far more than the steady 10 amps or so that used to be the case. The OP will also need to be well versed in using a direct connected ammeter, especially if it is a multi-meter. It is too easy to cause short circuits and ruin the metre or even cause a fire.

 

The fuel droplet thing can be checked by taking the injectors out, reversing each one on an injector pipe (no need to refit the leak off pipe) and crank the engine, inspecting the spray. There should be a small spray cone from one side plus the major cone of fine droplets that float in the air. There should be no streaks. IT IS VITAL WHOEVER TRIES THIS STAYS WELL AWAY FROM THE SPRAY and ensures there is nothing around to ignite it. This will not measure the injector opening pressure but i normally near enough for diagnosis purposes. If there is no small side spray or the main injection is streaky then the injectors need professional overhaul and testing.

 

Low compression. There is not much the OP can do to check this apart from ensuring each valve has some clearance unless he can get a DIESEL compression tester. As it seems they are now available at around £25 this might be a good investment, but we come back to removing the glow plugs and the potential for the tip snapping off. However, if the engine is cranking slowly that will also lead to low compression problems. If the OP is very experience then turning the engine over by hand and assessing the compression may give a clue, but that is no use if the only experience is with petrol engines.

 

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