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

[skipmac]

Originally Posted by 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

Agree. I will attempt all sorts of repairs that I haven't tried before but from all the research I've done and advice even from diesel mechanics, anything serious with an injector pump one should take it to a specialty shop.

That being said, you could try opening all the lines and flush clean fuel through everything and see if that helps. But would not attempt disassembly. DIY removal for sending to a shop might be an option but requires careful attention to timing when replacing it.

[canadianbeethov]

It can be bacterias or insects. You should get a good biocide.

[Sailmonkey]

Originally Posted by canadianbeethov

It can be bacterias or insects. You should get a good biocide.

Insects?

Do tell.....

[Nicholson58]

Originally Posted by 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.

Most fuel filters have bypass check valves. If the pressure drop through the filter exceeds the spring setting of the check then fuel bypasses the filter. There are many on the CF who dispute this but I have disassembled mine. They are there.

Obviously, keep the water out. There are many discussions on CF. We installed a polisher with water removal capability that is one micron absolute and quite large. This after loosing my HP pump to silt. You may be facing a lot of clean up at the least. If your pumps and HP injectors corroded it will be costly.

Your tanks are likely sludge buckets and will need to be cleaned and polished. Hope you have inspection ports.

Water gets in by many means. Condensation is often blamed but my ancient mechanic showed me that most enters through your deck fill port due to dried, Cracked O-ring. I keep new ones and they are easy to find at the chandlers. I use a thief to check the bottoms of my tanks. In five years of cruising I have found no water in my fuel except the occasional splash in Caribbean purchased fuel. I use a BAHA filter to transfer fuel into my tanks.

[DeValency]

My own 2 cents here, from a past, almost similar experience;

1. Most probably the problem is before the secondary filter, lines and primary are dirty with sludge from the old diesel. It is very unlikely for anything to pass the secondary filter - the dirtier/clogged it is, the better it protects the injection pump and injectors.

2. Considering you have polished the diesel all the way from the tank, including a thorough tank cleaning, lines, new diesel etc., as indicated, the primary filter/separator is the usual suspect. Note that even after a good cleaning and replacing the internal filter, some bacterial growth can be found internally - especially at the lower, in jar, internal check valve ball area that can stick the ball after few minutes. - I had three diesel mechanics on that issue, until the last one found a "flap" of sludge right there...

If you do not have a Separ/Racor, this is probably the time to invest in one (or two)... If you do, a thorough cleaning may do the miracle...

[LeighWebber]

If you intend to take the FI pump to a shop for cleaning, there are two things you MUST do first. One: with an awl, scratch a line across the FI pump flange and the gear case flange to record the EXACT relative positions. Timing on a Yanmar is adjusted by loosening the three bolts that hold the FI pump to the gear case flange. One bolt is at the bottom, one is between the FI pump and the engine block (a bugger to get at, but you can in fact reach it with a box wrench), and the third is near the top outboard side of the FI pump. It's that one you want to scribe. When you reinstall the FI pump, you will rotate it in and out (around that lower pivot bolt) until your scribe lines line up exactly. You MUST do this before loosening any of the bolts.

The second thing is even more important. The FI pump drive shaft is attached to a gear inside the gear case. The gear meshes with other gears, and the relationship between those gears must not be altered, or very very bad things will happen. Releasing the FI pump drive shaft from its big gear is a non-trivial task, and the specifics depend on the exact engine model you have. Whichever way you go about it, mark adjacent gear teeth with a sharpie so in case the gear itself has to be pulled out you can put it back exactly the right way.

Having said all that, cleaning the FI pump isn't that difficult. Have a look at

https://www.youtube.com/watch?v=21ogsKvAZCU

(similar FI pump). Before doing that, though, I think I would remove the fuel filter, remove the hoses that go to/from it, and used compressed air to blow all those little pipes clear. Make sure the hose from the fuel pump (the thing with the little priming lever) to the fuel filter is clear (blow it out), and the line from the primary (Racor?) filter to the fuel pump is clear. Take the latter hose and stick it in a jar of pristine diesel (from the marina fuel dock, not your tank). Make sure all the other hoses are attached. Loosen the banjo bolt on the line from the fuel filter to the FI pump. Use the priming lever until you get diesel
leaking out of the banjo bolt, then tighten it. Remove the high pressure fuel lines from the top of the FI pump and move them out of the way so you can see the openings into the FI pump. You will probably have to undo the high pressure pipes at the injectors and loosen the hold-down fittings so that you can move the high pressure pipes enough to see clearly. Now crank the engine and see if fuel pops out of the FI pump. You'll want to put some paper towels in the area to absorb the diesel, but there is surprisingly little that pops out of the pump. The goal here is to crank enough to push clean diesel through the FI pump so as to flush out any crud that may have gotten in there. You don't want that crud to hit the injectors, or they will get clogged and you'll have to pull them and take them to a diesel shop for cleaning and adjusting (not that expensive, BTW). Crank the engine in 10-second bursts, then rest it for a couple of minutes before repeating -- don't want to burn out your starter motor. When you are sure that clean diesel is coming out of the FI pump, re-attach the high pressure fuel pipes, and start your engine. Keep using the jar of pristine diesel, and stop the engine before the jar empties.

You now know that the engine is perfectly fine. Getting the fuel clean upstream from there -- well, you have had plenty of advice on that part of it.

Oh -- if the engine still doesn't start after doing all this, then the injectors need cleaning and adjustment. Should cost about $40 - $60 per injector.

[longjonsilver]

Originally Posted by Nicholson58

I use a thief to check the bottoms of my tanks.

What are you talking about?

jon

[JPA Cate]

^^^^ A long tubed suction device, such as wine makers use in wine barrels for checking how the wine is maturing, often called a "wine thief".

Ann

[skipmac]

Originally Posted by longjonsilver

What are you talking about?

jon

In this context a thief is a long pickup tube with some method of sucking liquid in (typically a rubber bulb). Stick the end of the thief through an inspection or other access hole down to the bottom of the fuel tank, suck up a sample and squirt it out into a clear glass jar to inspect for crud.

[thinwater]

Originally Posted by skipmac

In this context a thief is a long pickup tube with some method of sucking liquid in (typically a rubber bulb). Stick the end of the thief through an inspection or other access hole down to the bottom of the fuel tank, suck up a sample and squirt it out into a clear glass jar to inspect for crud.

An oil extraction vacuum is one of the handiest ways to vacuum the bottom, and most boaters already have one. All you need is a long, stiff wand to replace the dipstick tube.

[Cheechako]

The Algae, or whatever it is grows in the fuel, wherever the fuel resides. Potentially even in the pump or line.
When you say you " checked that fuel filter/water separator is clean" on your initial attempts, do you mean you just looked and the bowl was clean?
One thing I found on a boat that sat a long time is this cream colored algae had grown inside one filter housing to where it looked like tofu. It was kind of a rubbery mat in there.
Low hour engines can be worse than high hour engines....

[flyingfin]

Better do a complete flexible fuel line replacement, steel fuel line cleaning followed by fuel tank(s) draining and cleaning. Drain the tank and use a endoscope to inspect the interior for rust and deposits. Most likely the entire system is infected

[George_SD]

I just pulled my tank from the boat yesterday because I got a clogged fuel line between the tank and the filter. PIA to do, but it's the right thing to do if you are having bug/sludge problem.

Once it's clean and you are putting fresh fluid - do add stabilizer/biocide.

[more]

Originally Posted by ferrailleur

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

Clinazur Clin Azur 107 biocid
Curative treatment :
1.1000ml per 10000L of contaminated fuel to remove bacteria, yeasts, fungi etc.
2. Plan for removing the biomass by flitration or centrifugation.

Preventive treatment :
1. 1000ml per 10000L of fuel to prevent potential contamination when refuelling with diesel.

107 - Biocide for diesel sur ClinAzur Anglais

[Jack C]

Update to my problem. All lines from filter to injection pump now clean. New secondary filter. Fuel arriving at injectors but no firing. My guess is that water in the fuel caused bacterial growth in the lines after the filter. Apparently filters do not stop dissolved water.

I am now running diesel injector cleaner through the lift pump, secondary filter and then through the injector pump to injectors using the starter motor in bursts of 5 seconds. Impeller removed. Still no start but fluid is running back from injectors. Have let it sit for 24 hours and will try again.

Current theory is that injectors are stuck. Will probably have to remove and clean injectors or get new ones.