Squadron 58 - 2004 - Saloon Floor Removal

[MapisM]

J, the advice from Latestarter concerning unit injectors on a D12 was if it ain't broke, don't fix it. If you suspect a problem, he recommended carrying out a cylinder contribution test with a vodia tool to identify which, if any, injectors were failing, and then only to repair or replace that one.

N, aside from the Vodia thing which is obviously VP specific, do you possibly remember if LS1 suggestion was generically valid for any diesel engine, also of other brands, or strictly meant for VP/D12?

 

[Nick_H]

N, aside from the Vodia thing which is obviously VP specific, do you possibly remember if LS1 suggestion was generically valid for any diesel engine, also of other brands, or strictly meant for VP/D12?

Post #13 on this thread, seems a generic comment for EUI's.

http://www.ybw.com/forums/showthrea...0-hours-D-12-s/page2&highlight=unit+injectors

edit: he also makes the point further down that most "pump shops" don't have the facilities to test EUI's, so J if you do intend to remove and test them, you should make sure you can find a repairer with the right test facilities first.

 

[MapisM]

Thanks, now I remember that discussion. Which was very interesting, in more ways than one!
It's a pity that P doesn't seem interested anymore to contribute to the asylum...

 

[Portofino]

@ JRudge,
J what I have found in the Cote d Azur is the maintenance guys have problems evenly distributing there work load over 12/12 .
In the season they are busy , prep , service , breakdowns etc .Every body wants them April - August seemingly.

How ever over the winter as basically Med boaters hibernate they sractch about a bit trying to keep the guys busy etc .
So there’s a tendency to “big up “ work , cold work ,preventive work - .

The manufacturers s don,t help .
A lot of service schedules are written with American market,s ease of litigation in mind ,and warranties.

How ever having said that with reference to MAN , the modern EDC and CR stuff ( sorry MapishM yours are not these )
There’s no pull of injectors these days ,which confers with what LS says , regarding EUI,s

Every thing else on a mostly 2 Y basis — to cover there arse in USA but no injector service
https://marinedieselspecialists.com/man-maintenance.

Another point or anomaly is the x reference to the automotive sector with regard to pulling injectors .
1000 hrs is not a lot of miles .
I,am a big fan of plugging in the lap top and looking @ fault codes etc ,or checking your displays etc .

In theory there’s a concept flying around of sea air somehow getting in to the cylinder via open inlet ( and exhaust via the water in the riser ? ) valves when the engine is left unattended for months or what ever — leading to corrosion of the injector tip - hence problems ,
I don,t buy into that ,when idling mooring up it’s probably too rich and “ oiled “ up if you like when you shut down .
Of course not a damaging amount of “ contamination “ it gets blasted / burned off at the 1 st 1800 rpm next time you go out
Assuming P not D btw — but enough to prevent this corrosion theory.
Then of course you could be in the camp of regular winter starts , attempt to run em up on the dock , spread oil about etc .
This will counter any corroded tip theory too .,even if you don,t reach 550 degree of EGT. Due to no load at the dock .

 

[jrudge]

The people recommending it have nil financial interest.

Nick Barke only services his own customers in Cala Dor ( and I am not longer there). Volvo Paul is in the UK.

I know personally Rick from Cloud 9 who had this happen and hence for me this is something worth doing.

I believe PeteM had his pulled and whilst fine there were apart pattern issues.

I am not seeking things to do ( I have plenty) but when people I trust tell me D12s have a reputation for it and to get it done then I will listen!

 

[petem]

The people recommending it have nil financial interest.

Nick Barke only services his own customers in Cala Dor ( and I am not longer there). Volvo Paul is in the UK.

I know personally Rick from Cloud 9 who had this happen and hence for me this is something worth doing.

I believe PeteM had his pulled and whilst fine there were apart pattern issues.

I am not seeking things to do ( I have plenty) but when people I trust tell me D12s have a reputation for it and to get it done then I will listen!

I did but iirc correctly, the manual recommends that injectors are checked every X years on KAD44's (however I can't now find reference to this online). Anyhow, I just do what Col recommends.

 

[CLOUD9]

And what happened to Cloud9 engine? I must have missed it, if it was discussed here.

Hi. Not keeping up with the forum as much as in the past Im afraid. CLOUD9 suffered a problem last season. No prior warning. D12-800 450 hours. Smoke and minor vibration on way from Soller to Alcudia. Initially didn't appear to be a major fault, suspected a faulty injector but unaware of what that can mean. Engine instruments all reading ok. Continued at reduced revs (probably a mistake at the time). More smoke apparent when berthing in Alcudia. Conclusion was a failed No.1 injector causing hydraulicing and damaged valves. Engine lifted and refurbed. Happy to report that all has been well for 2017 season!

 

[MapisM]

Conclusion was a failed No.1 injector causing hydraulicing and damaged valves.

Blimey, do you mean that the engine got hydrolocked?
I wouldn't have thought that a faulty injector could go that far.
Though I heard of a holed piston following an injector defect - not sure what's worse... :ambivalence:
Glad to hear that you enjoyed your 2017 summer, anyway! :encouragement:

PS: coming to think of it, didn't you get any alarm/error code on the instruments?
Theoretically, the capability to "understand" a fault like this should be a big plus of electronically controlled engines...

 

[CLOUD9]

PS: coming to think of it, didn't you get any alarm/error code on the instruments?
Theoretically, the capability to "understand" a fault like this should be a big plus of electronically controlled engines...

I'm no expert... but the explanation was that No1 cylinder had been pumping diesel. I would have thought that it would have caused more than a minor vibration, but it didn't, and all instrument readings that I could scroll through were the same for both engines. No alarms, at all. No hole in the piston, but whilst engine was out I had new liners and pistons installed throughout.

 

[jfm]

PS: coming to think of it, didn't you get any alarm/error code on the instruments?
Theoretically, the capability to "understand" a fault like this should be a big plus of electronically controlled engines...

Alas no. Electronic engines don't know how much fuel volume goes into the engine any more than a mechanically governed engine does. An electronic engine ECU merely knows how much time the injector is opened for, and it deduces from that the fuel volume, using curves or look-up tables that come from CFD or empirical measurement. If the injector fails, causing lots of fuel to gush in even though the injector has opened for the correct amount of time, the engine cannot know.

 

[dj43]

Cloud 9s trouble sounds very similer to a friends engine trouble ,same engine around 400 hrs less than ten years old injector problem ,touch shy of 60k rebuild , that and other issues was deciding factor to not change our old tub this year , had two enquirers to sell and not even on market, not bad for the worst boat Fairline ever built according to some
Had our injectors checked and new tips at 800 hrs popped them out again this year had them checked no problems and no charge , couple of hrs work all good

 

[aquatom]

I'm no expert... but the explanation was that No1 cylinder had been pumping diesel. I would have thought that it would have caused more than a minor vibration, but it didn't, and all instrument readings that I could scroll through were the same for both engines. No alarms, at all. No hole in the piston, but whilst engine was out I had new liners and pistons installed throughout.

When the unit injectors fail in these engine they tend to stick open. When running at high rpm there is very little to show a problem except a slight vibration and a small amount of smoke. It’s when you slow down that it is massively overfueling and it starts to produce a lot of smoke. When you stop the engine the fuel continues to drip out of the faulty injector and slowly starts to fill the cylinder. It’s when you go to restart it that the damage can be done. I have replaced a few failed D12 injectors but never found that any more damage has been done.

 

[MapisM]

Alas no. Electronic engines don't know how much fuel volume goes into the engine any more than a mechanically governed engine does. An electronic engine ECU merely knows how much time the injector is opened for, and it deduces from that the fuel volume, using curves or look-up tables that come from CFD or empirical measurement. If the injector fails, causing lots of fuel to gush in even though the injector has opened for the correct amount of time, the engine cannot know.

Actually, I half recall a very interesting explanation from LS1 about how electronically controlled engines (in general) can indeed understand, at least to some extent, whether each injector is performing as it should or not.
If I got the gist of his explanation correctly, the trick is based on periodical routine checks, running behind the scene and totally unknown to the operator, where the ECU changes slightly the opening time of each injectors and measures the effect on engine load/rpm.
IIRC, the ECU can even adjust/calibrate (within limits of course) each injector whose contribution to the overall engine performance is under par - for instance, due to a slightly worn out nozzle.
On that basis, I would have thought that also an injector stuck open should be relatively easy to spot, because if by changing the timing instructions to that injector/cylinder there's zero effect/difference on engine performance, while all others "react" (so to speak) to the routine check, there's necessarily something wrong with it.
Now, whether I misunderstood completely LS1 explanations or simply VP did not implement such logic, I don't know - and I'm happy to be enlightened, in this respect.

 

[MapisM]

Had our injectors checked and new tips at 800 hrs popped them out again this year had them checked no problems and no charge , couple of hrs work all good

12 injectors removed, each one connected to the specific equipment meant to pressure check and test them, and eventually re-installed, in two hours and at no charge?
I'd love to have my boat serviced by the same engineer.

 

[jfm]

Actually, I half recall a very interesting explanation from LS1 about how electronically controlled engines (in general) can indeed understand, at least to some extent, whether each injector is performing as it should or not.
If I got the gist of his explanation correctly, the trick is based on periodical routine checks, running behind the scene and totally unknown to the operator, where the ECU changes slightly the opening time of each injectors and measures the effect on engine load/rpm.
IIRC, the ECU can even adjust/calibrate (within limits of course) each injector whose contribution to the overall engine performance is under par - for instance, due to a slightly worn out nozzle.
On that basis, I would have thought that also an injector stuck open should be relatively easy to spot, because if by changing the timing instructions to that injector/cylinder there's zero effect/difference on engine performance, while all others "react" (so to speak) to the routine check, there's necessarily something wrong with it.
Now, whether I misunderstood completely LS1 explanations or simply VP did not implement such logic, I don't know - and I'm happy to be enlightened, in this respect.

I remember that explanation too and it makes good sense. (Obviously the thing would measure rpm; it can't measure load, which is a derived figure). The thing I cannot figure out is that if the thing decides an injector is under par, what does it do? I've never heard of an alarm message on this, and if an injector is overfuelling it is much better to work the engine hard at high speed, not engage "limp home" mode, for the reasons AquaTom describes.

 

[petem]

12 injectors removed, each one connected to the specific equipment meant to pressure check and test them, and eventually re-installed, in two hours and at no charge?
I'd love to have my boat serviced by the same engineer.

If combined with other routine maintenance such as checking valve clearances I imagine the incremental effort to remove and replace would be in the order of 2 hours. As has been said before, some places make no charge for testing.

 

[benjenbav]

I remember that explanation too and it makes good sense. (Obviously the thing would measure rpm; it can't measure load, which is a derived figure). The thing I cannot figure out is that if the thing decides an injector is under par, what does it do? I've never heard of an alarm message on this, and if an injector is overfuelling it is much better to work the engine hard at high speed, not engage "limp home" mode, for the reasons AquaTom describes.

I've had a few injector failures in diesel motor vehicles which have manifested as the loss of the ability to achieve revs beyond a certain point - tremendous fun being able to get alongside a 56mph governed truck downhill on the m/way and then have it come back at you on the upslope, but I digress. Never experienced same in a boat. Reading the above, I was wondering if the different characteristics could be explained by:

(a) in a boat the engines would be likely to be set at 'X' rpm and left there for quite a while, whilst in a car the engine tends to be worked right across the rev range. If so, if - having detected an injector issue - you put the boat into limp home mode, would it even be possible to get the revs back up to a sufficient level to minimise the overfuelling?

(b) the injectors with which I had issues might have failed in the closed rather than the open position?

 

[MapisM]

I remember that explanation too and it makes good sense. (Obviously the thing would measure rpm; it can't measure load, which is a derived figure). The thing I cannot figure out is that if the thing decides an injector is under par, what does it do? I've never heard of an alarm message on this, and if an injector is overfuelling it is much better to work the engine hard at high speed, not engage "limp home" mode, for the reasons AquaTom describes.

Happy to hear that my memory wasn't playing nasty tricks on myself...

Ref. rpm/load, I didn't remember that specifically, but while writing I figured that it's a bit of a chicken and egg situation: in a boat at cruising speed, you set the desired rpm with the throttle, but the prop demand (hence engine load) changes constantly, depending on sea conditions.
So, I suppose that the check routine which we are discussing must consider separately not only rpm, but also the governor-driven load adjustments, to eventually identify the effects due to single injector adjustments.
That's just armchair software engineering anyway, and not so relevant once we agree on the principle.

Good point ref. what to do once a faulty injector is identified, anyway.
I agree that forcing the limp mode might be a bad idea.
And the best strategy for avoiding damages (shutting the engine off asap, and never turn it on again before pulling and checking that injector) might be even dangerous, if forced automatically.
But from my (as boat owner) viewpoint, I'd like to have at least a warning allowing me to decide what to do.

Oh, well. After all, who cares, when nothing of the above can be applied to mechanical engines anyway...!?

 

[MapisM]

the injectors with which I had issues might have failed in the closed rather than the open position?

Well, in principle those electronic routine checks should be able to identify also this type of fault, because obviously that cylinder would have zero contribution at all times, so the rpm would be unaffected regardless of how much/less fuel the ECU tries to squeeze in that injector...

 

[jfm]

I've had a few injector failures in diesel motor vehicles which have manifested as the loss of the ability to achieve revs beyond a certain point - tremendous fun being able to get alongside a 56mph governed truck downhill on the m/way and then have it come back at you on the upslope, but I digress. Never experienced same in a boat. Reading the above, I was wondering if the different characteristics could be explained by:

(a) in a boat the engines would be likely to be set at 'X' rpm and left there for quite a while, whilst in a car the engine tends to be worked right across the rev range. If so, if - having detected an injector issue - you put [You don't put it into limp home; some algorithm in the ECU does it] the boat into limp home mode, would it even be possible to get the revs back up to a sufficient level to minimise the overfuelling? [it would, if the ECU would let you. It might well be that ECUs do not generally engage limp home on detecting a weak injector; that is mere speculation I this thread. In the "behind the scenes checking" that we are recalling LS as describing, a nil contribution from a cylinder implies that it is over fuelling not under fuelling, and the correct thing for an ECU to do then is to cane the motor like a boss, at WOT, not limp home]

(b) the injectors with which I had issues might have failed in the closed rather than the open position? Yup. exactly. They can fail in either mode, and of course a simple open circuit will cause a fail close scenario. In LS's scenario if we are recalling it correctly, opening an injector for a bit longer should produced increased rpm (but not as big an increase as the other cylinders) in the case of a blocked or restricted injector, and nil increase in rpm in the case of either a flooding injector or a totally blocked injector. Thus, logically, the ECU should not limp home if it "feels" an faulty injector