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Reoccurring Engine Failure / Deisel Problem


Fish

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We have a reoccuring engine failure due to a desisel / tank problem

Boat is a 25 year old yacht with an Izuzu 3 cylinder engine off a 120l stainless steel tank.

 

First failure (engine died) was approx 6 weeks ago. Since then we have replaced all fuel filters (3 times), replaced all fuel hosing, had a reoccurrance so drained deisel tank and pumped out with a pump for changing oil (5 litre capacity - good suction). Removed maybe 2 cups of water and deisel bug clearly evident. Found out the deisel additive we were getting from Repco was a performance additive and not for deisel bug. Now have deisel bug addtive - put in dissinfectant dose and top up on every fill.

 

Engine has run fine on several occasions (couple of club races). Topped tank up from 20l jerry can, ran for 3hrs from Weiti to Westhaven 16nm 3hrs - fine. Ran for 2miles this morning, engine died. 40litres in tank. Went into Orakie, topped up with 20l new deisel, engine ran 5min and died again.

 

The enigne runs fine when we disconnet the fuel lines from the fuel tank and bung the min a the 20l jerry can beside the engine. We have gotten home twice now doing this including today with several (5) miles motoring / maybe 1hr engine time.

 

We were very thorough pumping out the fuel tank and flushing it with fresh deisel then pumping it out again - ran fine for a couple of club races and 16nm / 3 hrs the other day.

 

1) There was heavy rain between delivering the boat to Westhaven and today, could rain water leaking in the filler pipe cause this? (Stainless filler cap in cockpit floor, looks Ok but has an old rubber o-ring on it)

 

2) We keep the tank less than half fill for racing, would condensation in the winter cause a problem this quickly?

 

3) is it possible the 25yr old stainless tank / difficult to access -has other problems and needs to be removed and cleaned out?

 

4) could it still be deisel bug?

 

5) am I going mad and should I take up golf?

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1) There was heavy rain between delivering the boat to Westhaven and today, could rain water leaking in the filler pipe cause this? (Stainless filler cap in cockpit floor, looks Ok but has an old rubber o-ring on it)

I'd only be guessing with the other ones but I have had a mate (Volvo in a 1020) experience the same symptoms with this issue. New O-ring sorted it out.

 

Bloody good effort running it off the jerry can. :thumbup: At least you know there's nothing wrong with the engine itself.

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check the breather on the tank

breather line looks sketch / hasn't been replaced. Filling up from a bouser today kept on blowing back almost constantly i.e. breather could be blocked (we normally full up from a jerry can).

 

Could a blocked breather cause this? vacuum in tank / fuel pump can't pull against it / act like no fuel = would re start on priming then die again... hmmmm

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Not always. Especially if a line somewhere has the slightest little means ofn sucking a bubble of air. Hard to imagine a breather getting that blocked, but it is indeed possible it could cause the engine to stop if it were.

I recomend you install a CAV filter unit. Cheap units that take a common cheapf filter element and has a glass bowl on the bottom that allows you to monitor water and also allows somewhere for water to accumulate.

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Fish, I'm no expert when it comes to anything mechanical but I can relate some issues I have just had with my 3 cylinder Volvo Penta.

 

I only bought the yacht in Jan this year. The mechanical survey showed up motor issues but it ran fine. We had the stainless fuel tank internally inspected and it looked clean. I used the yacht for a couple of months before I put it in to get the motor rebuilt without any issues.

 

When I got the yacht back we kept having problems with it running well for a while then either stopping and/or running rough. It would run fine for hours then just stop. it turned out I had two problems.

 

1/ The fuel tank was full of diesel bug. This wasn't there when I bought the vessel and only occurred within the few months of owning her. I also used to leave tank half full or less. The diesel bug was put down to condensation in the fuel tank. I had been using some dodgy old fuel additive that came with the vessel.

 

2/ Air leak in the primary fuel filter housing. This was a pig to find but we (i.e. the diesel mechanic) eventually found it by looking at the glass bowl on the fuel filter when the engine was at higher revs. You could clearly see bubbles forming.

 

From now on I always keep my tank close to full, especially over the colder months. I also use a good quality diesel additive. Apparently there are some real rubbish ones being sold.

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Fish the bowser blowback issue could be to do with the amount of air/froth/foam that accompanies the diesel as it's being pumped into your tank. When you are filling from a pump, the handpiece takes up most of the space available, and the fuel takes up the rest, so air in the tank can't escape out of there while filling - it has to go out the breather. If the breather won't let air out fast enough, you'll get blowback. You'll also get blowback if the filler hose doesn't go on a relatively direct line to the tank. A couple of curves and it starts to restrict the speed at which fuel can flow. My boat has a similar problem when filling from the bowser at Gulf Harbour, yet I can fill it as fast as a funnel will let it go from a jerry can. At Gulf Harbour you should avoid the high volume diesel pump and also try filling it at about half trigger on the handpiece.

 

Definitely keep your fuel tank full during winter. Len Gilbert used to say this every year in diesel diary. There are a number of good diesel additives but I use Moreys and can notice the difference when I don't. It has a bug killer in it. From what you are telling us, the problem clearly exists before the lift pump. You've replaced the filters, but what about the filter housing? I agree with Wheels, get a cav dual housing that has a water trap at the bottom and a filter element at the top. They're not expensive and you can see what's going on. Getting your fuel tank out could be a bummer but it may be necessary as diesel bug is a bastard to contend with.

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1/ The fuel tank was full of diesel bug. This wasn't there when I bought the vessel and only occurred within the few months of owning her. I also used to leave tank half full or less. The diesel bug was put down to condensation in the fuel tank. I had been using some dodgy old fuel additive that came with the vessel.

It takes much longer than that for a decent amount of algae to grow. Algae grows at the fuel/water interface. It lives in the water, but It has to have a source of nutrients and that is the fuel. But it can not grow in the fuel. There are two parts to the Algae or Bacteria. One is the living oranism and the other is the dead matter. It is the dead stuff that sinks down into the Diesel itself and it wil also coat and stick to the sides of the tank.

When you dose a tank to kill it, it will of course sink down through the fuel. A good slosh around in a bit if sea and the gunge in the tank sides gets flushed free and floats through the fuel and of course will always block a filter at the worst posible time. The other issue is that a small amount of acid is produced and this creates little pit area's in the tank for rust to start. Hence why the gunge of some bugs can be also quite rusty looking.

The simple method is, no water, no fuel. So being able to bleed of the fuel every now and then to check for water and get rid of it is a good idea. Keeping the tank full has pluses and minuses. Yes it stops tank breathing due to air heating and cooling. But at the ame time, Diesel fuel itself has changed over the recent last couple of years and it doesn't store quite so well anymore. The enigne will still run on it, but it does still tend to lose some of it's goodies.

However, a full tank is good for having a boat ready to go when you want, so it is well worth doing it.

One thing that I don't do and recomending having changed on any boat is to return the return line back to the fuel line just before the Filters and not returned to tank. The fuel is warmed throught the injector pump and some engines have a very high volume flow and that can add to having air suck into the tank as it cools later.

Oh and in realtion to filters. Filters are often made to be one of two types. A pressure filter or a Vacumm filter. If you use one that was desinged for after a pump (pressure) on the before the pump side, it is very easy to have air sucked into the filter, so make sure you have the correct type.

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It takes much longer than that for a decent amount of algae to grow.

 

That's interesting Wheels. Following your logic that means that I probably had the diesel bug algae/bacteria before I purchased the vessel but the dead matter wasn't visible at the inspection. The yacht had been sitting idle at the marina for a long time before I bought it so that is distinctly possible.

 

I had to get the tank cut opened and the fuel lines flushed based on the recommendation after a fuel sample report. Cheap is was not!

 

The BP report I read indicated you could store diesel for 6 months safely as long as the ambient temperature was less than 30 degree's. I only have a 50L tank so can easily use that in a 6 month period. The report was dated 2002 so I would be interested if anything has changed since then.

 

Here is the report if anyone is interested.

 

http://amsca.com/files/Download/Fuel_news_long_term_storage_diesel.pdf

 

Fish - If it were me I would consider getting a fuel quality report. This would at minimum cross of the diesel bug as a potential cause. As Wheels has mentioned, you ought to have a decent primary fuel filter with glass bowl for water/colour inspection. The secondary filter is normally quite fine and can clog up very quickly (I learnt this one was from last vessel that didn't have a primary fuel filter when I bought it).

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Gidday Fish.

 

Sounds like a fun problem! At least you know the engine is OK, which includes the injectors and pump. When I had problems all 3 of these were kaput. (Read: $$$$$$$). It didn't help when I tried to take the injector pump apart. :oops: :oops: These are complicated little suckers full of delicate shims and all sorts. If you don't have all the gear, don't even start!! They are specialised items to set up too.

 

1. I can back up what others have said. Get a CAV filter/seperator, with a few spare filters. They have saved my life so many times. If possible, route the pipework so the filter seperator is close to the engine cover. That way you can check the bowl for water as you go. The nice thing about these units is that you can have water in the bowl, but that doesn't mean it's gone to the engine. You just drain it off, and away you go again. With a bit of possible sludge in your tank, you may end up changing filters a few times..

2. Get a new O ring for your filler. Cheap insurance.

3. Check that your tank vent is not blocked by removing at the tank and blowing through it.

4. Like Wheels said, check the diesel return line goes all the way to the tank.

 

Good ideas througout this thread. Should get you there.

 

Good luck!

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5) am I going mad and should I take up golf?

:lol: :lol: From my Golfing experience I'd say that would only accelerate your madness

 

Coming at your problem from a slightly differing angle. Over the last few months I've been having motor issues. Hard to start and wouldn't idle with occasional patchy running. Sent to Dr for full going over at which time I swapped motors so had to change connections. Doing that noticed the 'liner' of the fuel line had de-laminated, for lack of better word, so looked like it could have been occasionally acting like a non-return valve in backwards. New fuel line fitted and after the Dr's work things were massively improved. All was good but there was an occasional just didn't want to go without big tickles. No worries it's fecking motor and like software only put on the planet to piss with my head.

 

But last week I couldn't get the bitch to go at all. It wanted to but didn't quite get there. Motor doctor working on boat next door so said 'fix the cow'. A few hours later a call came in 'All good, grunge in the carbie'. Next day buggered if I could get it to go. Rang Dr who said Bugger going back for a look. After some head scratching and a few things the problem was traced to the CGI pack, a fecking 'black box'. Swapped black box and it starts instantly.

 

It appears the 'fuel issue' we (me and 2 Dr's) have been chasing was indeed the black box or at least a combo of box and fuel. These box things often go 'intermittent' on-off rather than just die instantly.

 

Is there a black box somewhere or something else maybe rather than fuel or only the fuel? Just mentioning that due to the above, it tricked 2 known and good Pro's, who, partially due to my explanation possibly, were looking in one area when it was actually a combo of issues.

 

Just sounds a bit weird your one to be fuel only especially after it looks like you have done all the right things. I'm thinking age may exclude the black box but a small bit of crap in the lines somewhere could be that non-return valve type deal I think I had. Any chance of blowing a nice bit of compressed air down the lines to shake loose any sticky crap? Just a thought after you saying it works fine when plugged into the jerry can.

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Following your logic that means that I probably had the diesel bug algae/bacteria before I purchased the vessel but the dead matter wasn't visible at the inspection.

I would say most likely, or it is possible it got dumped into your tank from a crook underground tank. Has been known to happen.

 

KM, the black box must mean we are talking petrol and the black box would be the powerpack. Yes they do indeed cause those issues. It is quite possible that the fuel issue highlighted the ppack issue.

 

Back to Diesel, we have had over the years slight variations in the chemical make up. It depends on where it comes from for one and that changed as various changes to the Sulphur content changed. The initial change was in simply finding a low sulphur content crude. But the real big change was when Sulphur was physicaly removed completely. During that process, many of the "aromatics" were also removed. In away that is a good thing. Less nasties coming out of the exhaust. But the problem is that these also acted as Solvents and that kept hoses and seals soft and slightly swollen. When the Aromatics went, the rubber components all dried and shrunk and became brittle. So vehicles soon had issues with leaks. The fact that sulphur was removed meant a few other additives had to be added. But like any thing that you add, it means it can un add itself by settling or evaporating or going off or what ever. So we started seeing fuels that seemed to go stale. For Diesel it is not a major issue because a Diesel is such that it would run on gumboots if you could get the things into the chambers. For Petrol, that was a completely different matter. The fuel will just not burn correctly once it is 6 months old. It is unbelievable the number of highy embarresd outboard owners that send the outboard in for a service because it just will not start and run and have it returned with the only thing done being a new tank of fuel supplied.

I believe we may start seeing some real big issues when we finally go to Biofuel added to the Diesel. But how far way that will be yet I dont know.

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KM, the black box must mean we are talking petrol and the black box would be the powerpack. Yes they do indeed cause those issues. It is quite possible that the fuel issue highlighted the ppack issue.

 

Knot these days even diesels have them. That's why if I buy a big diesel it won't have a black box. Which coincidently is the very same reason a well known gentleman deep into the diesel engine game just fitted non-black box diesels into his own boat when he had a lot more choices than all of us.

 

My post was more a 'don't get to fixated one one thing when there is a chance that could be masking or taking focus away something else that could be contributing' sort of the thing. As I found out last week, that scenario can happen quite easily even with the Pros.

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Remember KM, it runs fine when he just puts the hose into a 20 litre container of diesel.... Seems to indicate the problem is at the tank somewhere.. Not with the engine itself. I'd still fit the CAV filter though...

CAV diesel filter.jpg

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Knot these days even diesels have them.

Yes indeed they do. And the day of having a Diesel run on and on while Armagedon is happeing all around you, sadly has gone. In saying that though, the Diesels black boxes are engine managment systems and they set the timing of when the injector things have to do there jiggle about to squirt the fuel in. If it fails, you are screwed. But fortunately electronics are fairly robust these days. The main cause of concern will be in how they protect these electronic systems and their connections when in a Marine Environment.

The one system I get nervous about on boats is the Elecronic throttles, gear shifts and stearing.

Actually, there's another thing in modern cars now. Many modern cars have gone away from hydraulic stearing. Came across one just the other day and the stearing is all electronic. Hmmmm, not sure I like that idea.

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Hi Guys, thanks for all the replies,

We actually have one fo the CAV filters with glass bowl at the bottom. Only problem is its in a darn near impossible area to access - the flexibility of a 13 year old Russian gymnast is required to get a good look at it... Am currently considering repositioning it to be able to see it and assess this problem.

 

Went for another run today with the engine running off the jerry can - didn't miss a beat. That would give me some confidence its ntot a black box problem - don't think black boxes were inveted when this puppy was installed anyway. We were initially concerned there was an air leak one of the filters and checked that. Runs fine on the jerry can so are looking at issues with the fuel tanks itself again.

 

The breather looks munted so I'm going to check that and can changed it fairly easily. So the big question is the deisel bug and shite in the tank.

 

So if we've had deisel bug and am now using a good biocide, its likely there is still lumps of dead biomater floating about / getting stirred up etc? We're talking about pulling the tank out of the boat but that will be an epic job. Farrari, you got your tank cut open? was that just so you could clean it properly? How / where do you get a fuel assessment?

 

The return line goes straight back to the tank, Wheels, were you sayingthats good, or it should tee into the lift line?

 

We've also already replaced all of the flexible houses, incase they were delaminating on the inside and becoming non-return valves.

 

Is there any way of cleaning the tank out with any confidence without taking it out of the boat? Maybe use a solvent and pump it out? Any solvents emmulsify desiel bug shite?

What about a scope thingy for having a good look inside without removing the tank?

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Yes it is possible Bug is still in there. Yes there are chemicals that will disolve the stuff, but your tank will end up mimicing a shower rose more than a fuel tank. So the only way you can be really sure it is clean is to either get into it, which you probably can not easily do, or flush it. There are a couple of ways of doing this. One is called Fuel Polishing. And there are a couple of ways they do that also. the most complex is a high pressure pump that acts like a waterblaster and a hose that flails around inbside the tank. The fuel is drained to a series of high volume expensive Racor fuel filters and back to the pump and returned to that tank over and over till the fuel runs clean and clear. Then there are variations of that ranging down from that expensive unit, to the cheapest which is just a fuel pump that continuoly runs the fuel through a filter around and around. But it won't remove anything stuck in there. In the Us, there are people that have a set up like this that continually runs the fuel around even when the boat is tied up. That way they know the fuel is kept clean. Bit over the top if you ask me.

 

And no I return the fuel return line back into the main fuel line at the Filter. On most filters, and that CAV unit has it, you will see it has four fittings. Two in and two out. Just fit a fitting to the other in. They are marked with arrows. The returning fuel comes back in at the filter and mixes with the cooler fuel at that point. This stops warm fuel from being drained to the tank which heats up the tank and then later when it cools, draws in cool damp air. As long as the return line goes to the input of the filter, then you can not pressurize the reutrn line. If it was after the pump, many engines will not want to run with the return line under pressure.

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Fish, I had Marine Diagnostics perform the fuel analysis. It came back as a grade C where grade A is good and grade D is don't start the engine cause it will damage it. When they looked into the tank they could see a biomass of algae (Assume dead algae remains from what Wheels mentioned earlier). It looked like an old rotten straw front door mat when I had a look.

 

I used Bug Hunters to cut open the top of the tank and refit a stainless porthole of sorts. This way I can open it up again if I need too. They were able to do this with the tank still in the boat. My tank is under the port side seat in the main cabin so there was pretty good access.

 

Ian Meikle from Meikle Marine (027 4192140) put me on to these guys. In fact I let him arrange the whole lot as it was easier than chasing everyone. He had just saved me $15K on a motor rebuild due to his diligence so I wasn't about to penny pinch.

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