Smokin'

[slyworme]

Hi all,

 

My 16 year old BMC 1.8 has been doubling as a smoke generator for a few months now, starting last year with an intermittent (though constant) puff when idling to now producing continuous clouds of white, diesel-smelling smoke when doing anything and the engine is not running smoothly.

 

Over the last year I have:

 

1. Checked the lift pump and changed seals and diaphragm.

2. Checked all the fuel lines, washers and seals - nothing obvious

3. Changed the injectors - this seemed to make the engine run better though it is still not smooth.

4. Took the head off and de-coked it - exhaust valve stems were quite badly 'carbonated' but very little pitting on any of the valve seats . New gaskets and seals fitted when re-assembled.

 

I have just about exhausted (forgive the pun) all my options. I service the engine regularly and it has been a good reliable runner.

 

I have read quite a few threads about the injector pump timing possibly being out and the symptoms appear to be similar but I can't find an index mark anywhere on pump body or pump mounting flange to see if it has moved. Is adjustment easy (or possible) without these marks? The service manual talks about checking things such as the butterfly valve which I don't appear to have on the pump.

 

Last summer we did have a situation where the engine stalled due to a log caught in the prop - Could this have been enough of a shock to cause the timing to slip?

 

Any other thoughts on DIY solutions would be gratefully received before I call in the (no doubt expensive) experts.

 

Regards,

 

Mike

 

nb Bess

[WotEver]

Hi Mike,

 

Take a look at this thread, and in particular post #15 where in part, it's written "The 1800 pump is easy to see whether it has slipped because there is a line marked on one of the three lugs that secure it to the front plate studs. There should be a corresponding mark alongside it on the plate "

 

Good luck,

Tony

[slyworme]

Thanks Tony,

 

I've read that post before but I can't see any markings on any of the visible lugs or on the securing plate it bolts to.

 

Hi Mike,

 

Take a look at this thread, and in particular post #15 where in part, it's written "The 1800 pump is easy to see whether it has slipped because there is a line marked on one of the three lugs that secure it to the front plate studs. There should be a corresponding mark alongside it on the plate "

 

Good luck,

Tony

 

Regards,

 

Mike

[Albion]

Hi all,

 

My 16 year old BMC 1.8 has been doubling as a smoke generator for a few months now, starting last year with an intermittent (though constant) puff when idling to now producing continuous clouds of white, diesel-smelling smoke when doing anything and the engine is not running smoothly.

 

Over the last year I have:

 

1. Checked the lift pump and changed seals and diaphragm.

2. Checked all the fuel lines, washers and seals - nothing obvious

3. Changed the injectors - this seemed to make the engine run better though it is still not smooth.

4. Took the head off and de-coked it - exhaust valve stems were quite badly 'carbonated' but very little pitting on any of the valve seats . New gaskets and seals fitted when re-assembled.

 

snipped

Mike

 

nb Bess

 

White, diesel smelling smoke is due to incomplete combustion and can be due to many factors, many of which you seem to have covered in your list above. What I can't see from your list (in rough likelihood of importance and assuming that the valves were lapped in properly during the head rebuild) is:

1. Cylinder compression checks and valve clearances correctly set

2. Cracks in the cylinder head or between cylinders

3. Checking to ensure that the indirect combustion chambers are clear of carbon and aren't cracked.

4. Ensuring that you didn't leave an injector tip seal in one of the injector holes when you changed injectors (You did change tip seals and get them the right way up, I assume?).

 

Thanks Tony,

 

I've read that post before but I can't see any markings on any of the visible lugs or on the securing plate it bolts to.

 

 

 

Regards,

 

Mike

 

Because the mark on the lug is done by use of a special tool (expensive and relatively rarely used for a one off rebuild)

it is likely that the mark wasn't re-done if the pump has been replaced before and, in any case, can't be relied upon for perfect timing once the pump has been off.

 

A couple of questions:

1. Does the engine start cleanly, albeit with lots of white smoke, or does it misfire for a while before smoothing out (ie improving but not totally smooth) and still emitting white smoke?

2. Were the reconditioned injectors from a reputable source, sourced as exchange injectors, or were they from someone else who claimed that they were OK when they were last used on his engine?

Roger

[slyworme]

Roger,

 

Thanks for the notes. In response...

 

White, diesel smelling smoke is due to incomplete combustion and can be due to many factors, many of which you seem to have covered in your list above. What I can't see from your list (in rough likelihood of importance and assuming that the valves were lapped in properly during the head rebuild) is:

1. Cylinder compression checks and valve clearances correctly set

2. Cracks in the cylinder head or between cylinders

3. Checking to ensure that the indirect combustion chambers are clear of carbon and aren't cracked.

4. Ensuring that you didn't leave an injector tip seal in one of the injector holes when you changed injectors (You did change tip seals and get them the right way up, I assume?).

Because the mark on the lug is done by use of a special tool (expensive and relatively rarely used for a one off rebuild)

it is likely that the mark wasn't re-done if the pump has been replaced before and, in any case, can't be relied upon for perfect timing once the pump has been off.

 

1. I haven't got a compression tester but I have set the valve clearances. I did lap them though they were hardly any pits on them and I ensured they went back into the same hole they came from.

2 & 3. I gave the head a good inspection and clear out - nothing apparent in the way of cracks.

4. Are the tip seals the copper washers that were supplied with the new injectors? They were changed though I can't remember seeing any 'handidness' about them (and I did give them a good looking at).

 

A couple of questions:

1. Does the engine start cleanly, albeit with lots of white smoke, or does it misfire for a while before smoothing out (ie improving but not totally smooth) and still emitting white smoke?

2. Were the reconditioned injectors from a reputable source, sourced as exchange injectors, or were they from someone else who claimed that they were OK when they were last used on his engine?

Roger

 

1. The engine starts well enough though its running doesn't improve even when warm. It is running well enough to be able to tick over when warm though certainly not smoothly. The smoke is there from start up - quantity and colour doesn't seem to change.

2. The injectors were provided as exchange via the ABC marina shop at Hilperton. Not sure of the source though the chap did mention that the price depended on the exchange rate when I asked. They came individually bagged and blanked with replacement sealing washers.

 

Regards,

 

Mike

[Albion]

Roger,

 

Thanks for the notes. In response...

 

 

 

1. I haven't got a compression tester but I have set the valve clearances. I did lap them though they were hardly any pits on them and I ensured they went back into the same hole they came from.

2 & 3. I gave the head a good inspection and clear out - nothing apparent in the way of cracks.

4. Are the tip seals the copper washers that were supplied with the new injectors? They were changed though I can't remember seeing any 'handidness' about them (and I did give them a good looking at

 

1. The engine starts well enough though its running doesn't improve even when warm. It is running well enough to be able to tick over when warm though certainly not smoothly. The smoke is there from start up - quantity and colour doesn't seem to change.

2. The injectors were provided as exchange via the ABC marina shop at Hilperton. Not sure of the source though the chap did mention that the price depended on the exchange rate when I asked. They came individually bagged and blanked with replacement sealing washers.

 

Regards,

 

Mike

 

So, due to the lack of a compression tester we can't rule out poor rings, so that remains a possibility.

The seals are not the same as the copper washers that are supplied with the injectors. The tip seals are a small steel crushable washer that sits right on the tip of the injector surrounding the pintle. It is, from memory, about a cm in diameter, with a raised land running around it. The raised rim/land sits uppermost in the base of the injector hole. The copper washers are further up the body closer to the securing bolts. The tip seal prevents carbon deposits building up around the injector making it very difficult to remove at the next occasion and , if I remember correctly, they aid the dissipation of heat between the injector tip and the rest of the cylinder head.

Roger

Edited August 11, 2009 by Albion

[slyworme]

So, due to the lack of a compression tester we can't rule out poor rings, so that remains a possibility.

The seals are not the same as the copper washers that are supplied with the injectors. The tip seals are a small steel crushable washer that sits right on the tip of the injector surrounding the pintle. It is, from memory, about a cm in diameter, with a raised land running around it. The raised rim/land sits uppermost in the base of the injector hole. The copper washers are further up the body closer to the securing bolts. The tip seal prevents carbon deposits building up around the injector making it very difficult to remove at the next occasion and , if I remember correctly, they aid the dissipation of heat between the injector tip and the rest of the cylinder head.

Roger

 

Ahhh... In that case there is a good chance the old ones are still in the holes, if they were fitted originally - I can't remember seeing them when I changed the injectors and couldn't see where the new ones went as a result. I will check them this evening.

 

Regards,

 

Mike

[zenataomm]

............. might you have water in your fuel?

[slyworme]

............. might you have water in your fuel?

We had diesel bug over the Winter before last so there was some water in the tank but I cleared as much out as I could, put in some additives and kept the tank filled over the last winter.

 

I also checked the water trap as part of the low pressure side of the fuel system and there was nothing apparent in there.

 

Cheers,

 

Mike

[slyworme]

I checked the tip-seal washers and 3 of the old ones were still in the holes - the 4th may have fallen out without me noticing when I de-coked the head.

 

Fitted new washers and.... no change unfortunately.

 

I ran the engine for 10 minutes after doing the job last night and did notice that it runs a lot smoother at higher revs. I pushed it up to 3000 rpm and it was running quite smoothly (apart from the odd small cough) and the amount of smoke was reduced though still present. Acceleration up to that rev count was 'lumpy' at the lower rev count but it came down very smoothly as I pulled back gently on the throttle but with increasing amounts of smoke. It did idle but with copious smoke and certainly did not sound to have a nice tick-over.

 

I have someone coming round to look at it this afternoon - hopefully he can tell me what I've missed or broken

[Albion]

I checked the tip-seal washers and 3 of the old ones were still in the holes - the 4th may have fallen out without me noticing when I de-coked the head.

 

Fitted new washers and.... no change unfortunately.

 

I ran the engine for 10 minutes after doing the job last night and did notice that it runs a lot smoother at higher revs. I pushed it up to 3000 rpm and it was running quite smoothly (apart from the odd small cough) and the amount of smoke was reduced though still present. Acceleration up to that rev count was 'lumpy' at the lower rev count but it came down very smoothly as I pulled back gently on the throttle but with increasing amounts of smoke. It did idle but with copious smoke and certainly did not sound to have a nice tick-over.

 

I have someone coming round to look at it this afternoon - hopefully he can tell me what I've missed or broken

 

I think it might be worth removing those new exchange injectors and having them pop tested at a local diesel specialist. I'm not convinced, although it is difficult to remotely diagnose anything, that the injectors are good ones. Look in the Yellow Pages for a local Bosch diesel agent (or Lucas one if they still exist these days) and get them tested for cracking pressure and spray pattern. I have also had problems with leaking non-return valves between the delivery pipes from the injection pump and the pump body but that tended to cause missing in the early fire up which smoothed out after a few revs.

Roger

[Albion]

I think it might be worth removing those new exchange injectors and having them pop tested at a local diesel specialist. I'm not convinced, although it is difficult to remotely diagnose anything, that the injectors are good ones. Look in the Yellow Pages for a local Bosch diesel agent (or Lucas one if they still exist these days) and get them tested for cracking pressure and spray pattern. I have also had problems with leaking non-return valves between the delivery pipes from the injection pump and the pump body but that tended to cause missing in the early fire up which smoothed out after a few revs.

Roger

 

One thing you could do, as a bit of further diagnosis, before removing the injectors is to crack the pipe union open on each injector while the engine is running. If you have one faulty cylinder or injector then the cylinder where it makes least difference to the running is the suspect one. This doesn't help so much though if you have more than one faulty cylinder/injector. Look for smoke changes while you're doing these tests also. Usual caveats about being careul with high pressure diesel supply lines apply.

Roger

[slyworme]

One thing you could do, as a bit of further diagnosis, before removing the injectors is to crack the pipe union open on each injector while the engine is running. If you have one faulty cylinder or injector then the cylinder where it makes least difference to the running is the suspect one. This doesn't help so much though if you have more than one faulty cylinder/injector. Look for smoke changes while you're doing these tests also. Usual caveats about being careul with high pressure diesel supply lines apply.

Roger

 

Roger,

 

That's exactly what the diesel mechanic did this afternoon. Talk about deja vu (without the little thing above the 'u')! He has now taken the injectors away for testing as well. He also noticed that 2 of the injectors were by a different manufacturer which he didn't think would be a problem. I shall be ever so slightly 'miffed' if they are the problem as they were supplied by the boatyard (though also happy that it isn't anything worse).

 

Many thanks for the advice.

 

Mike

[slyworme]

Just a quick update. The injectors appear to be fine so out came the injector pump this morning to be tested first thing Monday morning. Not as bad a job removing it as I anticipated and I found the alignment marks on the pump body/mounting flange. The engineer looked at the pump and thought that there was a problem as he couldn't feel any resistance caused by the cams when turning the spline drive by hand. Will find out next week!

[Albion]

Just a quick update. The injectors appear to be fine so out came the injector pump this morning to be tested first thing Monday morning. Not as bad a job removing it as I anticipated and I found the alignment marks on the pump body/mounting flange. The engineer looked at the pump and thought that there was a problem as he couldn't feel any resistance caused by the cams when turning the spline drive by hand. Will find out next week!

 

I'm sure your guy will be aware but don't forget/lose the little torsion spring thingy that goes into the nose of the drive shaft and makes getting the pump back in a more difficult job to do. From memory it looks like a little metal mushroom with splines aroung the rim of the head. I think that its function is to take out any chatter/play between the drive spline and the splined pump shaft.

Roger

[Hairy-Neil]

The service manual talks about checking things such as the butterfly valve which I don't appear to have

 

Butterfly valve would only be found on road vehicle aplications. They were fitted by Leyland on Sherpa vans as a cheapskate way of obtaining vacuum from the manifold to work the brake servo, rather than fitting an exhauster/vacuum pump and were notorious for causing smoke if worn or incorrectly adjusted.

[slyworme]

I'm sure your guy will be aware but don't forget/lose the little torsion spring thingy that goes into the nose of the drive shaft and makes getting the pump back in a more difficult job to do. From memory it looks like a little metal mushroom with splines aroung the rim of the head. I think that its function is to take out any chatter/play between the drive spline and the splined pump shaft.

Roger

 

I have that safely in my possession - I guessed it had to be there for a reason and appeared to be the kind of thing that would be easily lost.

 

Butterfly valve would only be found on road vehicle aplications. They were fitted by Leyland on Sherpa vans as a cheapskate way of obtaining vacuum from the manifold to work the brake servo, rather than fitting an exhauster/vacuum pump and were notorious for causing smoke if worn or incorrectly adjusted.

 

Thanks - After 15 minutes of head-scratching and trying to tie the service manual picture to the actual pump I assumed that it was a mod/variation that wasn't fitted on mine.

[slyworme]

Got the pump back - nothing major wrong with it but the engineer made a few adjustments to up the pressure - not sure if that could be the cause of the problem but I will find out soon enough when I fit it....

 

Which leads me to the next question. Is there an 'easy' way of getting the torsion bar and pump drive splines to line up when refitting the pump? I assume that one of the special tools mentioned in the service manual helps but as it simply gives a part number it is not too descriptive.

[Albion]

Got the pump back - nothing major wrong with it but the engineer made a few adjustments to up the pressure - not sure if that could be the cause of the problem but I will find out soon enough when I fit it....

 

Which leads me to the next question. Is there an 'easy' way of getting the torsion bar and pump drive splines to line up when refitting the pump? I assume that one of the special tools mentioned in the service manual helps but as it simply gives a part number it is not too descriptive.

 

I don't remember a special tool being available for that job. I got mine back in just by some careful wriggling. Trouble is that you're trying to align a master spline (the one that's slightly wider than the rest IIRC) with the off-set torsion bar and get the pump back in, all at the same time. It can be done without any tools I can assure you.

Roger

[David Schweizer]

I do not wish to sound too much like a damp squid, but there is every possibility that your bores are worn and causing the problem. You do not say how many hours your engine has been run, but my old BMC 1.5 was 24 years old and had completed 20,000 hours when it started to display the same symptoms as yours, to the point that some people, half jokingly, were suggesting that the boat was on fire!!

 

BMC engines do have natural tendancy to smoke when under a light load or after a period of idling in neutral, so it can be difficult to tell exactly when bore wear is making the symptoms worse. When my engine was dismantled the bores were found to be almost ten thou. oversize at the worst points, further examination revealed that almost everything else was badly worn as well. The complete re-build has cured everything.

 

A compression test is really what yoy need before you shell out any more cash repairing components that may not be contributing to the problem.

Edited August 22, 2009 by David Schweizer

[Albion]

I do not wish to sound too much like a damp squid, but there is every possibility that your bores are worn and causing the problem. You do not say how many hours your engine has been run, but my old BMC 1.5 was 24 years old and had completed 20,000 hours when it started to display the same symptoms as yours, to the point that some people, half jokingly, were suggesting that the boat was on fire!!

 

BMC engines do have natural tendancy to smoke when under a light load or after a period of idling in neutral, so it can be difficult to tell exactly when bore wear is making the symptoms worse. When my engine was dismantled the bores were found to be almost ten thou. oversize at the worst points, further examination revealed that almost everything else was badly worn as well. The complete re-build has cured everything.

 

A compression test is really what yoy need before you shell out any more cash repairing components that may not be contributing to the problem.

 

Ahem, see post #4 Point 1.

Roger

[slyworme]

I do not wish to sound too much like a damp squid, but there is every possibility that your bores are worn and causing the problem. You do not say how many hours your engine has been run, but my old BMC 1.5 was 24 years old and had completed 20,000 hours when it started to display the same symptoms as yours, to the point that some people, half jokingly, were suggesting that the boat was on fire!!

 

BMC engines do have natural tendancy to smoke when under a light load or after a period of idling in neutral, so it can be difficult to tell exactly when bore wear is making the symptoms worse. When my engine was dismantled the bores were found to be almost ten thou. oversize at the worst points, further examination revealed that almost everything else was badly worn as well. The complete re-build has cured everything.

 

A compression test is really what yoy need before you shell out any more cash repairing components that may not be contributing to the problem.

 

The engine has, as far as I am aware, only done just under 1500 hours so I would be surprised if it is worn. It could be a broken piston ring maybe, however the mechanic who looked at it (and was carrying a compression tester with him) said that it started to well to be that and he was convinced it was a fuel system related problem. I suppose I shall find out tomorrow when I finally get all the air out of it.

[slyworme]

Latest update...

 

1. Compression check carried out - a touch over 200 PSI on each cylinder.

2. Dummy fuel tank used to break the fuel system in two. Fuel from a separate container was fed directly to the pump, therefore cutting out the stop cock, water trap, lift pump, filter and associated piping. Smoke and uneven running is still apparent so the fault must be in the HP/engine side of things.

3. Took the timing cover off today and, at first inspection, everything appears to be OK. I didn't have a short enough metal straight-edge to definitively check the timing marks on the crankshaft and camshaft lined up but using the straight edge of a piece of cardboard I couldn't see any misalignment. I will check with a ruler tomorrow.

4. While using the dummy tank, I broke the HP feed to each injector again. 1, 3 & 4 made the engine run even more roughly, 2 seemed to make the smoke reduce and there was no change in the running of the engine. Ah-ha! Swapped over injectors between 1 and 2 and ... no change. This time 1, 2 3 & 4 made the engine run rougher with the same amount of smoke. I'm not sure what could have caused those symptoms I can't reproduce them.

[Yoda]

BMC etc, iron blocks, suffer from most if not all problems related to component sizing.

 

You will find oval bores, miss fitting pistons with the wrong rings and twisted rods. Cranks that are not properly balanced and mains and caps not properly line bored.

 

Some of the problems are due to stress relief and most are to do with lack of proper tooling to produce factory tolerances.

 

 

I once was so fed up with an engine that no one could fix properly that I took it to a tuners and had it all balanced , statically and dynamically. The difference was just amazing. no tuning or anything else. Just an engine not fighting itself.

[slyworme]

Finally found the problem - the engine timing was out. I advanced the injector pump about 3 - 4 degrees and the smoke magically disappeared and it is running quite sweetly.

 

Now for the latest question...A number of people, include a diesel engineer and someone who service injection systems for a living, say that I should leave it as it is but I can't help thinking that if the pump timing was out (I'm assuming due to chain tension being wrong) then won't the valve timing be out as well?