CR Probs.

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Big Pete
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Re: CR Probs.

Postby Big Pete » Tue Jan 17, 2017 1:13 pm

I have also seen papers that suggest Bulbous Bows only work in Flat Calm Seas, it has always been known that they were only effective at one exact draught forward, much less useful than was thought. Another case where extrapolating from Models to full size doesn't work.

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Merlyn
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Re: CR Probs.

Postby Merlyn » Thu Jan 19, 2017 12:41 am

Funny how what was all the rage one day later falls out of favour the next.
Progress?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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Merlyn
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Re: CR Probs.

Postby Merlyn » Thu Jan 19, 2017 1:18 am

Well here's one guaranteed to get those few remaining hairs away from their lifetimes residence with Dave Winsor.
Back in the mid eighties and CR and Management systems are starting coming our way and it's all relatively new stuff after being in the trade ( at that point ) some 25 years plus for me.
As I have said before it's almost back to square one here, CR and electronic management systems etc etc to be learnt.
Park up the bearing scraper, the flogging spanners etc and reach for the oscilloscope and FCR and all the new out diagnostic equipment ( out in many, many forms )
First major problem encountered, engine runs fine for weeks then goes down to Limpo then cuts out.
Quizzing the operators ( most important to build up a picture with this new fangled diagnostic subject ) we are told leave it for a couple of hours then it starts and runs once again for several weeks, no probs. at all.
Been on several courses in the early days but note from the instructors that they too have problems taking it all on board re several issues.
It seems to be a case of " suck it and see " with some aspects of diagnosis and that only time spent gathering more experience in this new field and swopping it with others will foward our knowledge in this field.
So back to the problem child engine, go through every test sequence possible a hundred times involving several different engineers, employ the substitution method ( where possible as some components can, at that stage back then can only only be programmed by the manufactures ) and eventually and regretfully have to admit defeat on this one and call in the manufactures.
Now is my first very important lesson in learning about all this CR stuff is that they too are struggling and cannot crack it despite it was their firm who designed it, built it and possibly installed it.
Now this makes me and my workmates feel a whole lot better as I now realise that we are far from being on our own learning curve concerning this new fangled CR subject and as such in doing my new " apprenticeship " in this field I am now introduced big time to the substitution method.
The makers decide " we will try a new set of injectors "
This costs thousands of pounds on a " maybe " situation and certainly not a decision that I would wish to undertake financially for fear of me having to stump up the money in the case scenario of it not being the cure.
Weeks later and guess what?
It wasn't the cure.
Back comes the makers several times and other parts re tested and checked out, new ECU and more unnecessary parts fitted, alas to no avail.
So the conclusion is arrived at that each and every component/ sensor/ actuator etc etc has tested ok, so what on earth can it be?
Now we learn that other exact engine installations fitted with this management system are displaying similar symptoms causing excessive downtime and crews wages etc and yet no one ( including the makers ) can crack this one.
What an introduction to CR I am thinking.
About a year plus later we are told that a " modification " has to be carried out to this system and part no XYZ 1234 has to be fitted to this installation.
This, we are assured will cure this problem that has now be going on for over a year.
At this point I am going to stick my neck out and state that unless this has ever happened to you personally you will never, ever guess what part no XYZ1234 is and where it's new home is on the engine.
It did amazingly prove to be the cure when done.
So the conclusion is arrived at by all concerned " they don't know either so how the hell are we supposed to sort it ?"
Gives your confidence factor a major, major boost here but alas already some good engineers have already decided that the CR stuff is not for them and state they do not wish to go on any further courses concerning same.
Unlike my Liner question this is NOT a trick question but considering the excessive downtime laid alongside ( picture a single screw situation here- nightmare ) wages and tens of thousands of pounds lost in revenue and unnecessary parts what part no XYZ1234 is ( unless you have encountered this situation ) you will never guess in a million years.
So Dave's Kojak impersonation could well be achieved by night fall next weekend?
Or will someone else crack this one?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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D Winsor
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Re: CR Probs.

Postby D Winsor » Thu Jan 19, 2017 5:41 am

I'd venture to guess it was the addition of a "Ground" or "Earth" strap. Most control boxes on mounted on engines use rubber mounts to prevent vibration from the engine from damaging the components and preventing proper grounding of the box making a ground strap necessary

As Kojak would say "Who loves ya Baby"
Troubleshooting 101 "Don't over think it - K.I.S.S. it"

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Merlyn
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Re: CR Probs.

Postby Merlyn » Thu Jan 19, 2017 5:53 am

You are in the right area but a reversal of same?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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D Winsor
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Re: CR Probs.

Postby D Winsor » Thu Jan 19, 2017 8:30 am

Oh the ground connection was removed or was some sort of insulator installed between the box and ground. Was is something to do with my remarks in an earlier post in this thread about transient signals from other equipment being sent to ground and disrupting sensor signals through the sensor cable shielding or outright damage to the sensor cable shielding?

I did at one time have issues when a new digital control and engine sensor system was married to the existing very old shielded wiring for the original control and sensor system that caused all kinds of problems with sensor and control signal fluctuation and degradation. The fix in this case was to bypass the old wiring at a much higher cost than it would have been when the new system was first installed

When it comes to new Digital sensors and controls Good properly installed shielded wiring = Clean Signals = No Problems
Troubleshooting 101 "Don't over think it - K.I.S.S. it"

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Big Pete
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Re: CR Probs.

Postby Big Pete » Thu Jan 19, 2017 11:57 am

There is also the problem that ONLY ONE END of a shielded cable should be grounded, if both are grounded a current can flow through the shielding from end to end, inducing a current in the shielded cable....
Possibly a vibration damper for the Control Box mounting? or a smoothing capacitor across the power supply?
BP
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Merlyn
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Re: CR Probs.

Postby Merlyn » Fri Jan 20, 2017 12:35 am

Both getting close on this one, certainly amazingly in the right area considering the setup here and the no. of areas the problem could lie in..
Next part of the puzzle, what's part no XYZ1234 and where is it's new home?
Betcha can't come up trumps this time?
No lollipop here methinks for a while?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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D Winsor
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Re: CR Probs.

Postby D Winsor » Fri Jan 20, 2017 4:29 am

Could Part XYZ1234 be a diode across the leads to the coil of possibly a DC relay or solenoid valve to prevent the discharge of high voltage spikes being fed back into the system when the coil is de-energized?
Troubleshooting 101 "Don't over think it - K.I.S.S. it"

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Merlyn
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Re: CR Probs.

Postby Merlyn » Fri Jan 20, 2017 5:35 am

Lollipops back in the cupboard I'm afraid.
Clue?
Bizarre as it seems when all is revealed you have to use a torque wrench to complete this modification.
A wrist watch torque wrench to boot. ( well that's my interpretation anyway )
Come Monday there could be a few less here methinks.
Looking at your T's and P's over there it could be a tad colder for you.
On top anyway.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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Merlyn
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Re: CR Probs.

Postby Merlyn » Tue Jan 24, 2017 4:11 am

No more ideas forthcoming I see so herewith is your first clue to enable this problem to be solved.
The torque setting required is not in NM but in Foot Pounds and is at the other end of the scale to F.T?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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D Winsor
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Re: CR Probs.

Postby D Winsor » Wed Jan 25, 2017 3:58 am

Could Part XYZ1234 be some sort of adjustable mechanical tensioning or damping device, such as a spring maybe? The spring would then dampen any lost or uncontrolled motion in a linkage, such as linkage between the governor and fuel pumps, caused by vibration and or wear in the linkage joints. Hence the requirement of a torque wrench to achieve the proper setting of the device and prevent overloading or affecting the response timing of the actuator.
Troubleshooting 101 "Don't over think it - K.I.S.S. it"

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Merlyn
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Re: CR Probs.

Postby Merlyn » Wed Jan 25, 2017 7:33 am

I fear that extractor ( your pinkies ) may well be out again drawing a few more out before this problem is solved.
As it's CR it has no linkages /return springs/ Clevis pins / bellcranks whatsoever, even the throttle control is fly by wire or a potentiometer set up.
No external governor whatsoever, it's all in the ECU/ECM unit.
Frequencies / timings / widths of pulses injection wise all controlled by CAS ( crank angle sensor ) and the other CAS ( cam angle sensor ) together with all other sensors and actuators reporting back to obtain the best efficiencies throught all RPM/LOAD /TEMP. Ranges on the engine.
So no torque range possibilities here whatsoever.
However as we would say over here all is not lost.
Fear ye not.
We have to remind ourselves constantly that Diagnostics is a carefull process of Elimination.

In your attempts to solve this problem I personally think that your best method of attack here is to devise a two stage "thought filter " through which you can " Ram " all your writings on the site through in order to obtain the correct answer.
Why do this you may well ask.
Well at the risk of repeating myself Diagnostics = Elimination and as such as you have already stated the correct answer divert your minds eye away from the CR set up and see if your newly developed filter will strain all your suggestions leaving only the right answer for it is surely there in your writings on the site.
Best of luck, bit like the Liner question , it's staring you in the face, see what the filter reveals?
So DW writings/ Eliminations = Diagnostic Right Answer.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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Big Pete
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Re: CR Probs.

Postby Big Pete » Wed Jan 25, 2017 1:02 pm

Do you set cryptic crosswords when you are not on this site?

BP
It is always better to ask a stupid question than to do a stupid thing.

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Merlyn
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Re: CR Probs.

Postby Merlyn » Thu Jan 26, 2017 1:18 am

You asked me that before back along BT ( Big Tycoon as You are now to me ) and honestly I have never done a crossword in my life.
Expanding the CR problem overnight musing to myself as this is a LFO set up maybe the introduction of a sight glass in the line before the two thought filters would enhance the situation.
Picture the scene in your minds eye, two bleed nipples on the top, let go the first then the second and visually in your minds eye see yours and Dave Winsors answers swirling around the jar and let go all the incorrect answers leaving only the correct one.
The bleeding of the first stage of the system now complete.
Elimination exercise performed as necessary as on all CR probs.
At least you can now see the correct answer on visual.
Which and what to eliminate is down to the diagnostic performer, i.e. Your good self.
Expanding the subject even further perhaps JJ could be tempted out of semi retirement by offering more of that special inhibitor fluid to mark the papers concerning this problem, 68% , 72% or 84% pass mark JJ?
The 84% pass mark could carry the endorsement symbol of TDC ( no, not top dead centre ) Top Dog Chief.
The possibilities are endless.
How ever this ship needs to sail so can you crack this one which the makers couldn't do for about a year eighteen months ish?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.


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