both diesel engine shutdown simultaneously

[jann]

Both 240hp yanmar diesel engines on my friends 2007 34ft mainship trawler shut down simontaneously at Cape Sable on our trip to the keys last week.

We changed both fuel filters on each engine and was able to get them started. The filters were really bad, (the fuel look good).

We assumed that it was the filters that caused the shutdown. but it bothers me that both engines shut down exactly the same time.

both engines have independent fuel lines, independent computers and control circuits.

Has anyone out there ever heard of simultaneous shutdowns due to fuel problems, it seems hightly unlikely and I fear another intermittant problem is there.

 

[jleonard]

That is unusual. I guess the first thing I would do is make sure that each fuel system is open and no one inavertantly shut off one tank, etc.
I'm sure you checked that but might be worth another look, or another pair of eyes.
Usually a clogged filter will cause the engine to vary rpm before it quits. Did that happen?
If not then I'd look closely at the electrical circuit to see if there is a common circuit that might affect both enignes.

 

[Anode]

Crap in the tank plugging the pickup line which is probably common to both engines.
My best guess. What else fuel related is common to both engines?

 

[Forkliftt]

Did they start right back up after the filter change?

 

[Ocean Breeze NL]

Sounds like it was related to the common problem for sure ( dirty fuel ).

Elwin

 

[SomeSailor]

I would sooner guess electrical. Is there a place where both engines get their ground for the shut-down solenoids? Maybe a place where the wires run together?

Odd that they would die simultaneously. I would think the differences in the pumps and lines alone would keep one running form a few minutes longer than the other.

 

[sunchaser]

Jann - You said you changed both filters on each engine. Does the vessel have Racors or other type of filters in front of the on engine filters and were these changed too?

I too would lean towards crap or crud in the fuel pickup. Dirty fuel - it all is that is why we have filters. A friend's newer Selene just went through an engine shutdown due to construction debris in the fuel lines. Read the latest PMM where water left in a fuel tank on Parlatore's power cat during construction caused problems 5 years later.

Some newer engines are designed to shut/slow default down if the fuel vacuum gets too high, both engines could be (mis) wired together into each other's solenoid/safety devices. These are Tier II engines I would guess and Mainship was well into their financial woes by that time.

Maybe it is time to set up a good 3 stage filter setup like Jay Leonard has on his vessel. Oh by the way, how long had the filters gone unchanged?

 

[Scary]

I agree it's most likely electrical

I would sooner guess electrical. Is there a place where both engines get their ground for the shut-down solenoids? Maybe a place where the wires run together?

Odd that they would die simultaneously. I would think the differences in the pumps and lines alone would keep one running form a few minutes longer than the other.

Your not likely to HAVE BOTH ENGINES SHUT DOWN SIMULTANEOUSLY. This had to be caused by an alarm shut down or intermittent short or ground failure in the ignition system. Since both engines failed at once I would look towards the power supply for the ECU's. Both fuel filters may have needed changing, but it's unlikely they would cause instant shut down.

 

[Portuguese]

...90% or more of diesel engine suddom shutdowns are due to quality fuel problems. If it was bad for one, it was bad for the two of them...you said it:
"...We changed both fuel filters on each engine and was able to get them started..."

Cheers

 

[bobofthenorth]

We're all just guessing but if they actually shut down simultaneously then the immediate cause had to be electrical. The electrical cause could have been triggered by some sensor in the fuel system but a shutdown from fuel starvation absolutely would not shut down both engines simultaneously. Fuel starvation generally starts with lack of power, RPM decline and finally shutdown. If the shutdown is abrupt it is electrical IMHO.

 

[Marin]

We had an engine shut down due to an error I made in setting up a fuel transfer. One moment it was running along at 1600rpm, the next moment it got a slug of air from an empy saddle tank and it shut down instantly, as though we had pulled the stop knob (fuel cutoff). No stumbling, partial loss of power, just running and then stopped.

So in our experience diesels can quit instantly for reasons other than electrical. However in th OP's situation changing the filters cured the problem. We had to bleed our engine's fuel system before it would start again.

So since the only action taken was the changing or cleaning of the fuel filters the problem would seem to lie with the fuel or the fuel system and not with the engine's electronic control systems if they even have them.

 

[bobofthenorth]

Marin's no doubt right - there could be some hard to imagine confluence of random events that caused both engines to get a slug of air at exactly the same instant. Or there could be a common cause electrical shutdown. My money is on the electrical shutdown but we're all just guessing.

 

[timjet]

So jann let us know what you find out.

I've had an on-going fuel related issues with my engines causing rpm decay and once a shutdown of the starboard engine. I've cleaned everything including blowing all the fuel lines out, polishing the fuel, replacing the fuel tank selection valves and many racor element changes. The last thing I've done is to remove the racors, disassemble them put a seal kit in and replace. Since then I've had no problems, but I haven't had enough time on the engines to convince me that I've solved this issue.

 

[FlyWright]

Timjet,

Did you replace the engine mounted fuel filter? What engine do you have?

 

[markpierce]

A while back my engine would stall out after several seconds and was hard to restart if it hadn't been run for several days. Replacing the engine-mounted fuel-filter elements solved the problem.

 

[Marin]

Tim--- If you are experiencing rpm decay as well as shutdowns, I would certainly put an air leak very high on the list of suspects. Even a tiny one can cause the symptoms you are describing. Air leaks can be in fuel hose connections, filter spin-on or lid joints, a tiny crack in an injection pipe, injection pipe connections to the injector and the injection pump, fuel pumps, the list is actually pretty long.

 

[jann]

My observation:
when both engines failed together you could crank them but not run them.
one Gallon of fuel was removed and fuel looked good.
After one Gallon of fuel was removed ( from the racors ) engines ran.
When we got back we changed both Racors and engine filters.
No shutdowns after that.

I still suspect an electrical problem.
The only common thing I can think of is the halon system.
If there is a bad connection of halon pressure switch, momentarily fails, or bad ground it could shutdown both fuel solenoids.

anyother Ideas

 

[timjet]

Timjet,

Did you replace the engine mounted fuel filter? What engine do you have?

I have but not recently, but within the last 75 hours.

The indications don't seem to be a on engine filter issue. Each time I change the racor element the engine would get back up to speed. Sometimes for a few minutes and sometimes for a few hours. The problem is very inconsistent.

I used a diagnostic vacuum gauge and placed it after the fuel pickup at the fuel tank, then just prior to the fuel selection valves and then just prior to the racors. . I was consistently getting 0 vacuum on the diagnostic gauge, but still getting significant vacuum on the racor gauge. I then placed the diagonstic gauge just after the racor and it read the same as the racor, indicating to me the problem is with the racor and it's why I rebuilt the racor units.

Presumably if the on engine filter is clogged I would have gotten high vacuum readings on the diagnostic gauge no matter where I put it.

Before going through all this I had replaced probably 15 racor elements thinking that was the problem because after each replacement the engines ran fine, sometimes for 15 minutes, sometimes for several hours. Tony on boat diesel had me post a picture of a recently changed racor and after viewing told me to look else where, the element was not clogged. I also have a Fleetguard FS-1000 filter between the racor and the on engine filter and I removed it, cut it open and took a pic of it too. Tony said that one was OK too.

Engines are Cummins 330 6BT A5.9 M3's

Since doing all this I am getting a slight vacuum on the racor gauges at high rpm, but for some reason no vacuum on the diagnostic gauge which is now located just after the racors. They should read the same unless there is a gauge issue.

 

[timjet]

Tim--- If you are experiencing rpm decay as well as shutdowns, I would certainly put an air leak very high on the list of suspects.

Yes, good point Marin, one I haven't investigated. However I've only had one complete engine shutdown, and when I changed fuel tanks the engine started right up and ran fine at full rpm. I really can't explain why this happened but I was in probably 4 ft seas. In this particular case if it had been an air leak I don't think the engine would have started back up right away without having to purge the air out of the injector pump.

There was not a lot of fuel in the tank and perhaps junk had gotten into the fuel line and clogged fuel flow somewhere. I think maybe the fuel selector valves could have created the restriction because when I changed fuel tanks by repositioning the fuel selector valve the engine started up and ran fine. Later I checked the racor element and it looked fine.

 

[HopCar]

Timjet, have you pulled the pickup tube from the tank you're having trouble with? There is usually a screen on the end of the tube that will get clogged. I couldn't run off of one tank for about a year. It drove me nuts. I even pulled the pickup tube but there was no screen on the end. Finally I pulled the tube again and unscrewed the tube from the fitting it was installed in. The damn screen was at the top of the tube full of crap. I pulled the screen out and threw it as far as I could. I want the crud in my tank to get to my Racor where it's easy to deal with.

Jann, since we're guessing why both of your friends engines quit at the same time, here's my theory. Assuming both engines were running off the same tank, what if a piece of crap was large enough to block the pickup tube? Both engines would lose fuel at the same time. Then when you were changing the filters, the suction in the tube went away allowing the crap to drop off unblocking the pickup. Both engines would then start right up. Cape Sable is a long way from Sea Tow. Not a good place to lose both engines!

 

[timjet]

Thanks HopCar. Yes I check that, one of the first things.

 

[jleonard]

In this particular case if it had been an air leak I don't think the engine would have started back up right away without having to purge the air out of the injector pump.

The Bosch 7100 series pump on the Cummins 330 is self bleeding. They would purge themselves in a revolution or two of the engine.

 

[timb7734]

I had a Mainship Pilot twin before I had the current trawler built, it was a 2001 model. I would say the boat in the original post had a fuel tank issue, as these engines burn fuel at a greater rate than the engines in trawlers, for example, and either recently putting aboard a bad lot of fuel, or having a contaminated tank appear the issue, and under the circumstances both engines would go simultaneously.

Very bad for any modern Yanmar to be fuel starved, as the injection system depends on lubricity and cleanliness of fuel for lubrication as well as the pressures involved require extremely close tolerances. I believe the engines shut themselves down when fuel starvation is sensed.

Best course of action is to treat the tanks with STARTRON, available at West Marine or any good chandelry, and buy some extra filters. Startron will kill the algae, and liquify it to the point that the filters will remove it, but be prepared to change a few more. Then treat the tank pro actively anytime the vessel will sit for more than a few weeks in high temperatures or where day and nightime temps vary a lot. If you use Startron as I have for the past several years, you need not even keep the tanks full.

I have been in the trucking business for 40 years using heavy diesel engines, and as a matter of course diesel fuel loses 1% of it's cetane value each month in storage. Rather than keep a boat full, treat a low level of fuel when the vessel will sit, and fill up with fresh fuel when you depart for the next cruise.

 

[timb7734]

My trawler burns 1 GPH per engine on twin Yanmar 74 hp engines, at 7.5 knots without the gen, and it holds 1000 gallons, and I fuel once, maybe twice a year and treat it. I have never had any of the Racors show any pressure increase over their 500 hour life on the filter mounted gauges. The Mainship Pilot with the 250 twins burned more like 6 GPH with the same filters, the Racor 500's spin ons with the sight glass bottom.

I also have an express boat in the Great Lakes with twin 700 hp cats that burns 18 GPH per engine at low cruise, and I have been the recipient of a bad load of fuel that caused both engines to simultaneously drop to idle with two Racor 1000's, both open on each engine.

 

[FlyWright]

My trawler burns 1 GPH per engine on twin Yanmar 74 hp engines, at 7.5 knots without the gen, and it holds 1000 gallons

Not to hijack this thread, but I'd love to see pix and specs on your trawler.

 

[timb7734]

I put a couple photos in an album

 

[petersmarine33]

Engine shutdown.

Hello. Sounds like you might have diesel bug. This multi-type organism thrives on carbon fuels and lives at the interface of the diesel and condensation water in the tank. When it dies, it produces a stringy type bio-mass which gets sucked up the fuel delivery line and blocks primary filters. This usually occurs when you need it least !!
Are you running from a single tank?
Original fuel source is usually the main suspect, especially when fuel has ben stored for a long period of time. Often now, fuel producers cut mineral diesel with a percentage of Bio-Diesel. (from 7 to 11%)
Bio-Diesel is more hydroscopic than regular diesel so attracts the water out of the atmosphere the bug needs to survive on. Bio-Diesel also wrecks regular neoprene gaskets and pipes, with the resulting chaos.
The "shelf life " is less than 3 months !! before it begins to seriously degrade.You can even get the bug spores from a wet deck after a rain shower. It only needs a minute amount to cause havoc in your fuel system.
There are test kits to acertain whether or no you have a problem. A smell of sulphur or bad eggs from the diesel will also confirm the worse.
There is also available diesel tretmant compouds, but be sure to get the correct one as some of them are very expensive and ineffective.
I could go on and on about this subject as it is a bete-noir of mine.
Happy to clarify any points if required.
Good Luck with it, Regards, Peter.