BMC 1.5 diesel Fuel Pump and Nozzles issues after rebuilt

[Marko J]

I love this BMC engine since I heard its sound. It came with Ten Broeke boat which I've imported from Holland in 2019. Since then, I was lucky to sail 150-200 working hours on rivers (Danube, Sava, Tisza) and canals in Serbia.

 

1 - A problem arose: oil mixed with fuel after many oil dipstick checks. 

Diagnosis: bad Fuel injection pump and also AC pump (12v) which was used to replace old and not functioning original mechanical AC pump. Just one of four injectors working properly when tested.

 

2 - Solution and work: a. fuel pump rebuilt with new sealings and replaced idle part. b. new nozzles attached, c. new mechanical AC pump attached in order to replace 12v ac pump, d. old rubber fuel hoses replaced with new ones, d. drained out mixed oil and fuel (about 7 litters) and filled with SAE30 oil about 4,5 liters. 

 

3 - After rebuilt issues: unstable engine, hard to start (even it is cold outside, before was better), a lot of smoke (with now particular color), low revs when idle, changing revs suddenly, knocking inside in engine - strange sound, smoke with now color on the oil filler cap, a burst of oil particles when oil dipstick pulled out.

 

What I will do: a. check for fuel pump angle on engine block, b. check if I replaced old nozzles with proper ones (Tony Brooks suggestion) @Tony Brooks Where to find those pintaux type of nozzles? Thanks. 

 

Video immediately after fiting back Fuel Injection Pump and first ride shows no trouble at all. Its was 10c outside. Surprisingly I gained speed 2km/h more than It was before. After those videos, I have tried to start engine when was 1C outside (much more cold than first time) and noticed all described problems.

 

 

Edited December 17, 2021 by Marko J

[Tony Brooks]

1 hour ago, Marko J said:

I love this BMC engine since I heard its sound. It came with Ten Broeke boat which I've imported from Holland in 2019. Since then, I was lucky to sail 150-200 working hours on rivers (Danube, Sava, Tisza) and canals in Serbia.

 

1 - A problem arose: oil mixed with fuel after many oil dipstick checks. 

Diagnosis: bad Fuel injection pump and also AC pump (12v) which was used to replace old and not functioning original mechanical AC pump. Just one of four injectors working properly when tested.

 

2 - Solution and work: a. fuel pump rebuilt with new sealings and replaced idle part. b. new nozzles attached, c. new mechanical AC pump attached in order to replace 12v ac pump, d. old rubber fuel hoses replaced with new ones, d. drained out mixed oil and fuel (about 7 litters) and filled with SAE30 oil about 4,5 liters. 

 

3 - After rebuilt issues: unstable engine, hard to start (even it is cold outside, before was better), a lot of smoke (with now particular color), low revs when idle, changing revs suddenly, knocking inside in engine - strange sound, smoke with now color on the oil filler cap, a burst of oil particles when oil dipstick pulled out.

 

What I will do: a. check for fuel pump angle on engine block, b. check if I replaced old nozzles with proper ones (Tony Brooks suggestion)

 

Video immediately after fiting back Fuel Injection Pump and first ride shows no trouble at all. Its was 10c outside. Surprisingly I gained speed 2km/h more than It was before. After those videos, I have tried to start engine when was 1C outside (much more cold than first time) and noticed all described problems.

 

 

The knocking noise in the first video might be diesel knock caused by poor atomisation but as it is in a narrow rev band I would check the engine mounts for damage and security. If the nozzles are wrong the noise could be broken bits of top hat heat shield burying themselves in the piston crown. When you take the injectors out look down the hole. You should see a small hole into the cylinder less than 6mm diameter, if it is more or jagged then that heat shield has broken. If it is closer to 12mm then the heat shield is missing or stuck on the injector. Did you remove the old crimped atomisation washers and fit new ones under the nozzle as well as a new copper seating washer.

 

Bad cold starting could be indicative of the wrong nozzles and cranking for a long tom will fill the exhaust tract and cylinders with unburned fuel so it will take time to blow out out and stop smoking.

 

Edited to add - it is not unknown for the inexperienced to knock the pintles off both type of nozzle so when dealing with injectors take great care and when you get yours out make sure the pintles are still in place. Having no pintle would compositely mess up the fuel atomisation so bad starting and   smoke even it will stars.

 

Edited December 17, 2021 by Tony Brooks

[Marko J]

I think I got wrong nozzles. They have some kind of protrusion instead of flat head. In that protrusion there are main hole and secondary hole. 

 

Today I've checked injectors, and moved slightly fuel pump - it was 1-2 degrees outside of proper position. Results are not so good still. 

@Tony Brooks Does this nozzles cant be involved in all the problems I noticed after Fuel Injection Pump?

 

Engine after checks and refitting fuel pump> 

 

 

 

 

 

Edited December 17, 2021 by Marko J

[ditchcrawler]

Is this any help Diesel Tractor Injector Testing and Overhaul (anglo-agriparts.com)

[Marko J]

14 minutes ago, ditchcrawler said:

Is this any help Diesel Tractor Injector Testing and Overhaul (anglo-agriparts.com)

Thanks, it's very helpful! Maybe nozzles are just right after I read this. 

Edited December 17, 2021 by Marko J

[Tony Brooks]

Marko J That should be a pintaux nozzle and the auxiliary spray hole is in the side of the little bump. Your injectors should NOT have a flat end, those with a flat end are the wrong ones.

 

However I can't see if the needle pintle is still in place or if has been knocked off. Also I can't see the auxiliary spray hole, you need a good light and probably a magnifying glass to see that. We need a close up almost side view of the nozzle to see the pintle.

 

Have you looked down the injector holes in the head to ensure the top hats are in place and not broken. maybe a photo in good light?

 

The tickover seems a bit low to me. but not much.

[Marko J]

Nozzles are new. There is needle pintle on all of them. 

 

Injector holes look all the same to me. 

 

 

 

Edited December 17, 2021 by Marko J

[Tony Brooks]

The top hats look OK but the crimped atomisation washers/heat shields look as if they have not been changed. They seem heavily coated with carbon, I wonder if they have been leaking. Lets ask @Tracy D'arth for a second opinion.

[Marko J]

The only thing I put below the injector is copper heat shield. Something like flat ring, it's on the picture of injector.

Edited December 17, 2021 by Marko J

[Tony Brooks]

1 minute ago, Marko J said:

I changed washers/heat shields with new copper ones - check the pic with injector. 

 

The atomisation washers are not copper, more like shaped steel. See image here https://www.bobbeckfuelinjection.co.uk/bmc--diesel-injector-heat-shield-washer-2719-p.asp

 

The washer on the injector is NOT the atomisation washer, it is a sealing washer. The washer I am on about that right at the bottom of the hole and the nozzle seats against it.

[Marko J]

1 minute ago, Tony Brooks said:

 

The atomisation washers are not copper, more like shaped steel. See image here https://www.bobbeckfuelinjection.co.uk/bmc--diesel-injector-heat-shield-washer-2719-p.asp

 

The washer on the injector is NOT the atomisation washer, it is a sealing washer. The washer I am on about that right at the bottom of the hole and the nozzle seats against it.

 

For the first time I see this 🤣

[Marko J]

So how many rings-seals - washers do I need on every injector when attaching to engine block?

[Tony Brooks]

16 minutes ago, Marko J said:

 

For the first time I see this 🤣

 

I thought it was in the manual.  It is:

 

I doubt it will make much difference to your problems unless the they are leaking.

 

If any top hats came out stuck to an injector did you fit a new copper washer on them where they seat on the head.

 

 

Edited December 17, 2021 by Tony Brooks

[Marko J]

Now I see. I dont have atomizer sealing washer at all. But does this lack of washers can produce problems with engine running? 

 

 

 

[Tony Brooks]

32 minutes ago, Marko J said:

Now I see. I dont have atomizer sealing washer at all. But does this lack of washers can produce problems with engine running?

 

 

It will lower the compression ratio but as I would never fit new injectors without new washers I don't know how it would affect the running. It is vital that you ensure no old ones are left down the hole, there may be more than one down there. They can be difficult to remove so I use a long, thin screwdriver and small hammer to try to knock it loose then a little hook made from an old spoke tohook it out.

[Tracy D'arth]

1 hour ago, Tony Brooks said:

The top hats look OK but the crimped atomisation washers/heat shields look as if they have not been changed. They seem heavily coated with carbon, I wonder if they have been leaking. Lets ask @Tracy D'arth for a second opinion.

I got used to calling the steel corrugated washers "fire washers"  because that's what they are in, very hot down there.

[Marko J]

I see now. Thank you for help. Another opinion came from fuel injection specialist - bad quality nozzles mixed with lack of washers. We will test every nozzle and compression too and see if it is true. He asked me about origin of nozzles and concluded - "oh, I know those, with laser scribed letters on it.... It's pure crap coming from China...probably few are already dead, and engine stalls because of that... quality ones are with engraved text try to find them". I think, this is it: 

 

https://www.asap-supplies.com/products/bmc-injector-nozzle-for-bmc1-5-thornycroft-90-engines-12h834-131121

[Tony Brooks]

40 minutes ago, Marko J said:

I see now. Thank you for help. Another opinion came from fuel injection specialist - bad quality nozzles mixed with lack of washers. We will test every nozzle and compression too and see if it is true. He asked me about origin of nozzles and concluded - "oh, I know those, with laser scribed letters on it.... It's pure crap coming from China...probably few are already dead, and engine stalls because of that... quality ones are with engraved text try to find them". I think, this is it: 

 

https://www.asap-supplies.com/products/bmc-injector-nozzle-for-bmc1-5-thornycroft-90-engines-12h834-131121

 

If you intend to test pintaux nozzles on a pot tester then you rally need an additional piece of kit that simulates the pressures during cranking so you can see the output of the auxiliary spray hole.   If your diesel chap does not have that bit of kit you can go some way to simulate the adaptor by pressing the pop tester handle down slowly so the pressure rise is slow enough to allow  the auxiliary spray to work.

[Marko J]

A diesel man will do the testing. He have all the machines. I just prey and hope that I didnt ruined something else like piston rings during few engine starting with new nozzles and pump. There is a big difference between engine sound, cranking and operating from the first after rebuilt starting and last one. 

 

First start after pump rebuilt and with new nozzles: 

 

Sound one week later after few cranking (without any sailing):

 

 

[Marko J]

After I removed injectors, I found just 3 of 4 heat washers bellow them. After checking injectors, one of them had no completly dead.

 

- I've ordered 4 new nozzles and heat washers from Asap supplies UK.

- Specialist rebult them and put them back.

 

Result after first firing:

 - alot of smoke coming in bursts 

- better sound than previous

- oil pressure when cold 20 psi

- oil pressure when warm 10 psi/ oil pressure when idle warm 5psi

- high idling revs when warm

- smoke coming from oil cap opened

 

So, now, are those are symptoms of warm piston rings or maybe oil pressure valve? 

(This is a video just a minute after starting)

 

 

Edited January 4, 2022 by Marko J

[Tracy D'arth]

Crankcase fumes from the rocker box suggests poor sealing between bore/s and piston/s.  = low compression = poor starting and uneven running especially at tick over.

 

Oil pressures are low, cold tick over should be over 40psi, hot at least 20psi.  Cold revving should be 70psi when the relieve valve will open.

Check the seating of the relief valve, its under the dome nut on the  side of the block. It could be stuck open or badly worn. Check  that the pressure gauge is accurate.

Otherwise its a well worn engine or less likely a worn oil pump.

 

Edited January 4, 2022 by Tracy D'arth

[Tony Brooks]

A very worn engine, worn cylinders, pistons & rings. Worn bearing and possibly a worn oil pump. Add to that there is a distinct posibilty the valve guides are worn. In my view with the poor starting and such a low oil pressure it is overhaul time but by all means take the oil pressure relief valve out and make sure the plunger is a nice sliding fit but do not pack or stretch the spring. This assumes the oil pressure gauge is more or less correct.

[Marko J]

Thank you @Tony Brooks and @Tracy D'arth. It seems I will spent rest of the winter rebuilding my engine. Does someone know how much money basic rebuild of inner engine components can cost ? Approximately... 

[Tony Brooks]

That is impossible to answer at this stage, anything from a few hundred if you are lucky or do a bodge job to a few thousand probably. From your posts I wonder if you have the equipment and knowledge to do the job properly.

 

Before your question can be answered you need to measure, check and assess the crack shaft, can shaft, cylinders, pistons, oil pump, head and block faces, connecting rods, small ends, timing chain & tensioner, oil pump, connecting rods, valves & valve guides and cam followers. Ideally you would check the main and big end bearings for backing, butting and nip, but I am sure this is often not done. Only after you have the engine in bits and all that done will you be able to cost the new parts and machining required. If you are dead lucky you MIGHT get away with new piston rings, main bearings and big end bearings but how long lived the result would be is open to question. More realistically look at a re-bore or re-sleeve, crank grind or new crank, new big end and main bearings as the minimum.

 

You will also need new oil seals and an overhaul gasket set.

 

I would suggest that you also look at finding a second hand engine that you can see start from cold and run for a while. Be aware that so called overhauled/reconditioned engines could be anything from a wash down and spray paint to work that returns the engine to an almost as new condition.

[Marko J]

Thanks for all answers. Engine rebuilt and works like new one now. It was messy inside - especially with bearings, shafts and sealings. Leak of fuel was due to bad workshop on fuel pump by previous specialist.   

 

Edited March 26, 2022 by Marko J