Diesel blockage

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RJJ

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Hi everyone. Having run perfectly for three years, the engine cut out today (loss of revs then quietly came to a halt) during a spot of bumpy motor-sailing. On inspection there is a little gunge in the water collection bowl below the first filter, which wasn'tthere when we set off. We diverted to an anchorage and I will address it in the morning. I would really appreciate thoughts on the optimal sequence.

1. Change filters and try to start engine.
2. If no success, check the fuel lines and try to unblock.

I am guessing 1 will likely work. If so, then should I

3. Stock up on filters, double dose with fuel set, and soldier on. Or
4. Proceed to tank cleaning and all that jazz.

Anything else I should do? Many thanks.
 
1. Change filters and try to start engine.
If no success bleed the lines at the injector(s) until no bubbles occur, then start.
2. If no success, check the fuel lines and try to unblock.

I am guessing 1 will likely work. If so, then should I

3. Stock up on filters, double dose with fuel set, and soldier on, monitor the water separator and stop water from getting in if needed (filler cap / hose in focus). Or If the problem persists, then
4. Proceed to the commonly larger than expected job of tank cleaning and all that jazz.
 
ChromeDome said:
1. Change filters and try to start engine.
If no success bleed the lines at the injector(s) until no bubbles occur, then start.
2. If no success, check the fuel lines and try to unblock.

I am guessing 1 will likely work. If so, then should I

3. Stock up on filters, double dose with fuel set, and soldier on, monitor the water separator and stop water from getting in if needed (filler cap / hose in focus). Or If the problem persists, then
4. Proceed to the commonly larger than expected job of tank cleaning and all that jazz.
Click to expand...
Yep, what ChromeDome said. Seems likely the choppy seas stirred up some gunge.

I'd ensure water removed from bottom of tank. Suck out with a pela pump or similar if there is no drain plug.

Maybe change to a different fuel treatment as the deisel bug can become resistant, just like other microbes become resistant to antibiotics.
 
Change/check the filter first. It should be pretty obvious from that as to whether the flow of fuel was the problem.
 
I had the same issue in choppy seas. The engine note also changed. A filter change got me going again for few weeks. After that I removed the tank and removed much gloop.
 
I don't want to be alarmist, but exactly those symptoms resulted in me having to have a new fuel tank! We (or rather, a marina engineer) got all the things done that have been suggested, which got the engine going again. On returning to our home marina, I had the tank cleaned out, thinking that was all that was necessary. Next time we came to her, we found the bilges full of diesel - the rust on the inside of the tank had been all that was keeping the fuel in! Fortunately, we had enough access to remove the old tank and have a new one fabricated.
 
James_Calvert said:
It's so obvious that it couldn't be overlooked could it but...

Check the tank for fuel.
Click to expand...
:)
Which is why the RAC man always checks the fuel gauge, even if there's a trail of oil and bits of piston behind the car!

I had a similar mishap to the OP several years ago, resulting in a rather traumatic entry into Portsmouth harbour under sail. Yep, blocked filter, the bouncing around had stirred up the crap in the tank. I went to a car breaker and picked up a matching pair of spin-on filters. Same piping - I used copper and, in spite of the fact that it's unsuitable, I never had any problems - and taps from ASAP, and I had twin filters, running on one and able to switch to the other in seconds if necessary. Of course, it never was and, after that, I only changed filters when they got rusty enough to be a concern, twice in the 15 years I kept the boat.

One other tip that might simplify bleeding is to fit a bulb pump between the tank and the filter. I didn't need to on my old boat as the filter and pump were below the tank level, but have on the new one because the take off is through the top of the tank.
 
When this happened to me it was gunk in the bottom of the tank which blocked the fuel line. The filters were clear. I now have a sump with a drain in the tank.
 
You probably have a basic gauze filter on the end of the fuel pick up line inside the tank itself. If there's gunge in the tank, it can get disturbed in boisterous seas, and this then blocks the "pre filter" and stops the engine.

Once the engine has stopped, the lack of suction lets the gunge fall away, allowing the engine to restart.... but it will most likely happen again, and at an awkward moment.

Solution..... withdraw the fuel line and inspect. Worse case scenario, remove tank and then empty and clean it before filling with clean fuel.
 
I had a similar scenario, including anchorage with no sensible chandlery access. Fortunately I had a jerrycan of diesel and was able to use that as an emergency fuel tank. It didn't give much range as the return continued going into the original tank, but was enough to get out of the anchorage and then into a marina .
As per Rustynight it was the end of the fuel pipe that was blocked with crud
 
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In my case, it happened a couple of times a few days apart. I changed both the CAV filter and the engine filter, hoping it would solve the problem.

Sods law decided to take a hand when entering Lymington one day, and that's when I knew more investigation was needed. Luckily at the time no ferries were moving, or it could have been interesting.

The CAV filter was clean, which led me to the fuel pick up..... which had what looked like wet blotting paper stuck to it.
 
I would suggest you ignore the advice to just sorting the filter and restarting. Your filter will be full of air and you want to avoid this air reaching the HP injector pump or you could be struggling to prime at an inconvenient time. At least ensure ALL the air is removed from the filter. My filter is before the lift pump so I achieve this by slightly over pressurising the fuel tank with a dinghy pump and release the trapped air via the filter bleed screw or by slackening of the fuel pipe to the lift pump. Once all the air is out of the filter I would then bleed through the the injector pump body using the lift pump as there could be water in the line and injectors and pump do not like water especially mucky water. Once clean bubble free fuel is seen at the pump body bleed then try to start. If no pump body bleed slacken off the fuel supply pipe to the injector pump. Doing this should avoid getting more air or water into the fuel pump.

An examination of the filter may give some indication of what the problem was and what further action may be necessary to avoid a repeat.
 
RJJ said:
Hi everyone. Having run perfectly for three years, the engine cut out today (loss of revs then quietly came to a halt) during a spot of bumpy motor-sailing. On inspection there is a little gunge in the water collection bowl below the first filter, which wasn'tthere when we set off. We diverted to an anchorage and I will address it in the morning. I would really appreciate thoughts on the optimal sequence.

1. Change filters and try to start engine.
2. If no success, check the fuel lines and try to unblock.

I am guessing 1 will likely work. If so, then should I

3. Stock up on filters, double dose with fuel set, and soldier on. Or
4. Proceed to tank cleaning and all that jazz.

Anything else I should do? Many thanks.
Click to expand...
My guess is you have diesel bug. You boat isn't old enough to suffer some of the suggestions posted here. Even with regular biocide treatment you can still get it. I dose regularly and still had some in my tank. If I was you I would buy a small facet type fuel pump, some clear hose and the biggest inline fuel filter you can find. Some copper pipe attached to the clear hose poked in the access or remove a sender guage if you have one. Vacuum the bottom of the tank returning the filtered fuel to the tank continuesly.
By doing this you will remove anything that will block the filters in the future. You will know how bad the problem is. You will know what's causing it. You will also have the kit for the future. It costs very little. You can then double dose if it is fuel bug. Change your filter and you are back in business with certainly you can cope with the issue
 
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geem said:
My guess is you have diesel bug. You boat isn't old enough to suffer some of the suggestions posted here. Even with regular biocide treatment you can still get it. I dose regularly and still had some in my tank. If I was you I would buy a small facet type fuel pump, some clear hose and the biggest inline fuel filter you can find. Some copper pipe attached to the clear hose poked in the access or remove a sender guage if you have one. Vacuum the bottom of the tank returning the filtered fuel to the tank continuesly.
By doing this you will remove anything that will block the filters in the future. You will know how bad the problem is. You will know what's causing it. You will also have the kit for the future. It costs very little. You can then double dose if it is fuel bug. Change your filter and you are back in business with certainly you can cope with the issue
Click to expand...
Thanks, sounds good advice. Indeed it's a plastic tank so corrosion isn't the problem.
 
Never Grumble said:
Loads of online stuff on how to build your own fuel polisher.
A write up of this home made fuel polisher is in the most recent PBO magazine.
Click to expand...
I don't think it needs something so sophisticated. A cheap see through car fuel filter, the biggest you can get or a bunch of smaller cheap ones so you can change them when they get clogged will do for now. I bought ones used for filtering biodiesel. Big see through types. Did the job well. Plastic mesh so cleanable in petrol
 
Hi and thanks everyone.

This morning I have removed the pick up tube which was straightforward. Three inches of black snot came out at the bottom. I used a hand pump to take a pint out from the very bottom, which seemed free of water and gunk.

Also confirming a 2/3 full tank.

Then changed the filter. Engine now running well. But obviously there is a likelihood of more gunk in there, so will avoid bumpy motoring until cleaned the tank somehow.

Thanks for everyone's help.
 
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