Floris - the aftermath?

[cpedw]

Back on the boat on Sunday, first time after that storm. During the storm, the boat got a serious shaking-up on a swing mooring. She was seen pitching about 30° during the wind.

After starting the engine (Volvo MD2030D from 2001), I was surprised when it just died after a couple of minutes. Fortunately, I hadn't let go of the mooring! A couple of tries to restart just turned over, with no sign of firing. This hasn't ever happened before in 9 years of my ownership.

I suspected fuel trouble. The tank (150 litres) was about 3/4 full according to the gauge. I tried the priming pump on the fine filter with the bleed screw open but nothing emerged. I put 20 litres into the tank because I couldn't think of anything else to do. After a bit more head scratching, and about 45 minutes after the first start/stop, I tried the starter again. After a slightly longer hesitation than normal (a handful of seconds), it started. Susequently, the engine operated as normal for 2 hours in 4 sessions.

What do you think might have happened? Was it connected to the severe shaking by Floris? Could it be a sign of diesel bug or other muck in the tank? I put a dose of bug killer in just in case.

 

[RunAgroundHard]

The fuel outlet from the tank likely has a wire gauze filter in it. A good shoogle of the tank by the waves could have dislodged dirt and blocked the filter. The dirt may have just been pulled through and caught by the filters. The shougle could have caused air to enter the pipe as the boat rocked and rolled and fuel sloshed around. That air has now worked through the system and becuase you don't have an air leak, the engine now runs.

If it was my boat, based on your experience, I would plan to drain and clean the tank this winter. I would also replace the filters this winter. My own experience of tanks, on older boats, is that the tanks do accumulate waste products, either dirt, impurities in the fuel, or products from water, diesel mix and maybe bug.

It has been a warm summer, and good agitation with water and dirty fuel may be a breading ground for fuel bug. Probably just disturbed dirt.

 

[garymalmgren]

RE What do you think might have happened? Was it connected to the severe shaking by Floris? Could it be a sign of diesel bug or other muck in the tank? I put a dose of bug killer in just in case.
Along with . I tried the priming pump on the fine filter with the bleed screw open but nothing emerged.

It is most likely connected with contamination in the tank.
The engine has stopped this time and it is telling you something. You should really listen to it.

To test you can remove the fuel line before the filter and drain a fair amount (4 litres or so) into a clear bottle, let it settle and see what you have.

Your best bet is to take the inspection hatch off the tank and have peek inside.
There is most likely a collecting of water, sludge and maybe organic contaminants.
In the case of the first two, bug killer will have no effect.
If it is bad you will need to drain the tank, clean it. You can reuse the fuel if you strain it carefully.

If you have no hatch, decanting the whole tank (a time consuming hassle, but necessary in ,many cases) is the safest thing to do.

My advise is, now that the engine is back running, do not think that the problem has gone away.

gary

 

[[70521]]

What basic engine checks have you done, or have you just looked at it and scratched your head?

Does it turn? Have you bled the fuel system? Have you checked all the wiring? Have you sworn/insulted it? Have you done a B. Faulty and hit it with a tree?

 

[ylop]

What basic engine checks have you done, or have you just looked at it and scratched your head?

He told us in his post…

Does it turn?

Clearly, it not only turned over but eventually started.

Have you bled the fuel system?

He tried to but never saw fuel so it’s either air got in and he didn’t try hard enough or crap stopped fuel getting in.

Have you checked all the wiring?

He hasn’t mentioned that, but what wiring fault were you imagining that stops it starting, lets it turnover and then spontaneously resolves itself?

Have you sworn/insulted it?

He got as far as adding extra fuel to the tank to I assume he did step 1 first!

Have you done a B. Faulty and hit it with a tree?

So that’s really the only unknown!

 

[Ian_Edwards]

Almost certainly contamination in the tank blocking something in the fuel line from the tank to the engine.
I would build a cheap and simple fuel polishing system.
1) Get a temporary stand pipe you can introduce into the tank, long enough to reach the furthest corner of the tank. You don't give enough information to be able suggest how you can get it into the tank. Ideally through an inspection hatch. But there are probably other ways, if it's a problem, please provide more details and there'll someone on the forum who will attemp to help.
2) Aquire a small fuel pump, cheap 12v version are widely available online.
3) Get CAV fuel filter and plenty of spare filters elements.
4) Connect the stand pipe to the filter, then to the pump, with suitable flexible plastic pipe. Put the output from the pump back into the tank.
5) Poke the stand pipe into the bottom of the tank and power-up the pump.
6) Agitate the tank as much as possible. The idea is to get as much of the detritus into suspension as possible.
7) Check and replace the filter as required.
8) Repeat 6 and 7 until the system runs clean. This could take quite along time, many hours, but in my view we'll worth the wait. Detritus in the fuel tank is an engine failure waiting to happen. Often at the end of a long rough passage, entering an unfamiliar harbour.
9) Replace All the filters in the system.
The above is an alternative to emptying the tank and mechanically cleaning it. Probably not quite as good. But often a much more practical option.
Here's "one I made earlier". I broke the glass bowl on the CAV, last time I used it. I have a replacement (stored safely), but I've not fitted it as yet .....
I'd only break it again!
I use this every spring and it's amazing how much water and detritus it removes.

 

[garymalmgren]

Good system Ian.
Here is a better orientation.
As mentioned , this is with the glass bowl missing.
The only changes I would suggest is a generic Chinese knock off filter housing and a higher capacity pump, again Chinese.
That little fellow would take ages to recirculate 150 litres.


gary

 

[[70521]]

He told us in his post…

Clearly, it not only turned over but eventually started.

He tried to but never saw fuel so it’s either air got in and he didn’t try hard enough or crap stopped fuel getting in.

He hasn’t mentioned that, but what wiring fault were you imagining that stops it starting, lets it turnover and then spontaneously resolves itself?

He got as far as adding extra fuel to the tank to I assume he did step 1 first!

So that’s really the only unknown!

Our ideas on checking an engine, bleeding the fuel system in particular, differ considerably.

 

[Ian_Edwards]

Just for clarification. My photo of the fuel polishing system was taken with the system stacked, on its side, in the corner of a very crowded garage .... I don't know why I call it a garage, its never had a car in it, it's aways been full of boat bits!

 

[Supertramp]

I would change fuel filters or at least the primary as a precaution. Depending on the filter type you may be able to see deposits or whatever if you examine and rinse in some clean diesel. All clear doesn't mean there isn't a block in the fuel tank.

If you have a bottom drain from the tank, check this. I run off a little each season and there is usually a little sediment present.

Checking you reach max revs and perhaps find a nice choppy windward motor to test!

 

[NormanS]

If you have a bottom drain from the tank, check this. I run off a little each season and there is usually a little sediment present.

I run off a little, several times in a season, and particularly on the day after a rough sail.

 

[cpedw]

Thanks for all the advice. I'm thinking of going the fuel polishing route as there's not a hatch in the tank, just a hole for the gauge (about 40mm diameter).

Looking at the ASAP site, they have a page devoted to polishing which is helpful but the filter prices are eye-watering! From over £370, up to £500. I was thinking of changing the engine's CAV pre-filter to this spin on CAV replacement for <£50.
Am I naive to think the spin-on will do OK? Then I can replace the CAV in the boat after polishing,

Is it possible to give a guess at how many filter elements I'll need? And how many cycles of the tank contents it might take?

 

[garymalmgren]

RE the filter prices are eye-watering! From over £370, up to £500

Even the 45 quid one that you have found is over priced!! You will notice that there are no fittings supplied,

One option is to go down to the truck breaker's yard and take your choice of high quality Japanese filter housings.
Then buy generic filters.

A Chinese unit is 8 euro.
R12S R12T Kraftstoff Wasserabscheider Filter Dieselmotor für Racor 140R 120AT S3240 NPT ZG1/4-19 Autoteile Kompletter Combo-Filterbecher - AliExpress 34

 

[The Q]

Almost certainly contamination in the tank blocking something in the fuel line from the tank to the engine.
I would build a cheap and simple fuel polishing system.
1) Get a temporary stand pipe you can introduce into the tank, long enough to reach the furthest corner of the tank. You don't give enough information to be able suggest how you can get it into the tank. Ideally through an inspection hatch. But there are probably other ways, if it's a problem, please provide more details and there'll someone on the forum who will attemp to help.
2) Aquire a small fuel pump, cheap 12v version are widely available online.
3) Get CAV fuel filter and plenty of spare filters elements.
4) Connect the stand pipe to the filter, then to the pump, with suitable flexible plastic pipe. Put the output from the pump back into the tank.
5) Poke the stand pipe into the bottom of the tank and power-up the pump.
6) Agitate the tank as much as possible. The idea is to get as much of the detritus into suspension as possible.
7) Check and replace the filter as required.
8) Repeat 6 and 7 until the system runs clean. This could take quite along time, many hours, but in my view we'll worth the wait. Detritus in the fuel tank is an engine failure waiting to happen. Often at the end of a long rough passage, entering an unfamiliar harbour.
9) Replace All the filters in the system.
The above is an alternative to emptying the tank and mechanically cleaning it. Probably not quite as good. But often a much more practical option.
Here's "one I made earlier". I broke the glass bowl on the CAV, last time I used it. I have a replacement (stored safely), but I've not fitted it as yet .....
I'd only break it again!
I use this every spring and it's amazing how much water and detritus it removes.

I built a similar system, only with a glass Demijohn before the filters that allowed the detritus and water to settle out.. less filters used that way.