How could it happen? Algae growth in hose after filters and before Injection Pump

[Jack C]

My Jeanneau Sun Odyssey 36i started life as a charter boat with Sun Sail. The next owner hardly used it so for the last four years the engine Yanmar 3YM30 has probably run for a maximum of 50 hours.

This week I tried starting it after 2 months of non use.

The engine fired instantly, roared for a few seconds then died. Further attempts to start failed.

I checked that fuel filter/water separator is clean and by opening the bleed screw at the next filter established that fuel is arriving at the next filter. There was a little air that I bled.
Still did not start.

I cracked open the nut at the aft injector. No fuel when cranking the engine with throttle open. I cracked open the nut where the injector pipe leaves the injection pump and cranked. Still no fuel.

I loosened the nuts on the banjo fittings on the hose feeding the injector pump from the filter and pumped fuel using the lever on the pump. Fuel flowed.

I opened the filter on the engine. The cartridge has black muck and so has the bowl. The metal bottom of the cartridge is brown which appears to be rust presumably caused by water in the fuel.

I cut open the cartridge, the inside is clean.

Then I removed the hose with the banjo fittings. The fuel is meant to flow through the bolt and then through orifices just before the bolt end.

The lower bolt smaller orifices were clogged with black algae. The upper bolt with larger orifices were also dirty but not clogged. The inlet to the injector pump looks clean.

Here are my thoughts. I would appreciate any comments.

My positive test of fuel arriving at the injector pump by loosening the bolts did not establish fuel getting to the injector pump. The fuel bypassed the blocked lower orifices.

There is no fuel arriving at the injector pump or the dirt has clogged the pump and maybe the injectors. The reason for engine not starting.

The initial engine start and roar was due to a build up of oil or fuel in the cylinders.

My question is:

How did the algae get past the two filters?

My thoughts are that the fuel has dissolved water that went through both the separator-filter and filter on the engine.

The water separator-filter is probably not effective to separate water at the flow rate of probably less than 10 liters per hour (based on 2 liters use and 70% return to tank) of a small engine.

Through engine non use, the water separated out of the fuel in the hose and created an environment for the algae to grow.

Can anyone think of any other reason?

I cleaned the filter bowl and banjo fittings. I am about to re-assemble with a new filter. Hopefully the engine will start.

Should I run injector cleaner though the pump and injectors?

Any advice or comments welcome.

[Compass790]

I'm sorry if this is obvious but I didnt see any mention of a biocide in yr post.
I'd be tempted to drain & clean tank & refill with clean fuel with added biocide. I'll let others comment on injector cleaner as I've never used it.
We had a similar problem but it's never recurred after washing tank with gasoline & using biocide in the fuel. Ours was caused by no o-ring on fill cap when we bought the boat!

[Lepke]

I use a biocide every fueling. I never had algae problems in 60 years.

Filters are mainly for debris that would damage the injectors or pump. Small particles of "algae" can pass thru. When sitting in a filter, fuel line, etc., it can multiply.
I would guess you're changing your primary filter, but not the secondary to have that much water. Or the brand of primary housing you use is not separating water out.

[thinwater]

Originally Posted by Lepke

... Filters are mainly for debris that would damage the injectors or pump. Small particles of "algae" can pass thru. When sitting in a filter, fuel line, etc., it can multiply....

^This.


a. Obviously, we are talking about bacteria and fungi, not algae. Algae require light and are not related to fuel contamination.


b. Bacteria are really small, like 0.2-1 micron. The smallest fungi cells are generally a little bigger, more like 2-5 microns.



c. Filtration is nominal. A 1 micron filter passes millions of particles at 5-10 microns, and it only takes 1. Then they grow fresh colonies on the other side of the filter. This is particularly true of systems that are not used daily.


You can reduce fouling with filtration and water reduction, but you can't 100% stop it. Biocides help, but MUST be used as a preventative, not as a treatment (if used as a treatment, they kill big colonies, they float loose, and clog everything). Regular use helps.

[john simons]

Happened just like that to me. The bug goes through the pre filters and a thin brown deposit blocks the engine filter. I used a biocide to kill the bug, and installed a fuel polishing system that runs from the bottom of the tank.
The engine failed several times (like 0200 entering Cherbourg)until completely cleared. I now dose every filling.good luck ! John

[skipmac]

Originally Posted by Lepke

I use a biocide every fueling. I never had algae problems in 60 years.

Filters are mainly for debris that would damage the injectors or pump. Small particles of "algae" can pass thru. When sitting in a filter, fuel line, etc., it can multiply.
I would guess you're changing your primary filter, but not the secondary to have that much water. Or the brand of primary housing you use is not separating water out.

If I may ask, which biocide do you use?

[ferrailleur]

Just curious...
How much biocide? I never dose.
Can it be too much is too much?
Thanks

[Apollo366]

BioBor JR is what I and many charter boats use.

Why? Because we know it works.

BTW, When I got my current boat it started having intermittent surging & stopping issues. This was finally correctly diagnosed as a dirty fuel tank & very old filtering type of system.
Had to open up the fuel tank & found that prior "cleaning" had only done 2 of 3 chambers!! Mech made another access port in 3rd chamber and cleaned out over one pint of black algae from it. Renewed all fuel lines & fitted new modern Racor filter with squeeze bulb to make bleeding less painful. Has worked well for over 200 hours.
Also found barnacles growing & blocking the SW line from inlet to engine! Replaced line & inspected and cleaned as needed remaining SW lines.

[Apollo366]

Follow dosing directions on bottle, too much will loosen all the existing growth and you'll be cleaning filters for months. But this would be a sign that you need to clean your tanks & lines of existing growth.

[Lepke]

Originally Posted by skipmac

If I may ask, which biocide do you use?

Many over the years, but now I use Archoil AR6200 for about 10 years. I use it because it also adds lubrication and I get about 6% better mileage because of the better combustion. I have Detroits with mechanical injectors and haven't changed an injector in the 10 years I've used it.

If you're interested, you can get it online at archoil.com or Amazon and ebay.

[Apollo366]

I think I'm gonna change brands.

Many thanks Lepke.

[skipmac]

By the way, Practical Sailor did a test a few years back on biocides. Not truly a definitive test but did offer some interesting insights.

https://www.practical-sailor.com/boa...esel-additives

[longjonsilver]

Originally Posted by thinwater

a. Obviously, we are talking about bacteria and fungi, not algae. Algae require light and are not related to fuel contamination.

There are many things in this world that are not called the correct scientific name by the public. Whatever phyla they belong to, they are causing problems in peoples diesels. i am looking at buying a boat that the diesel won't start. Owner thinks its rings and bearings, he mite be rite, but i think that there is a good possibility of bugs in the diesel plugging things up. If that is true, then that is an easy fix compared to an engine overhaul.....But this thread is a good reminder that the bugs will get into other parts of the fuel system besides the fuel tank. Gotta clean them all out.

Anyone know how to clean an injector pump?

jon

[thinwater]

Originally Posted by longjonsilver

...Whatever phyla they belong to....

Kingdom. Bacteria are are in eubacteria. Fungi are in fungi. Algae are in protista. None are relatives, other than being alive. Kinna like sayin' a fly is the same as an elephant... only they are much more closely related.



Just playin' with you. It does mater, however, in understanding what they need to survive.

[Apollo366]

Anyone know how to clean an injector pump?

jon
___

Yes, take it to a Diesel Shop, they are way too precise to DIY.
Oh, and don't forget to note the timing setting if it's got one.

Capt Wayne