Gunk in the fuel tank

[Mickeyrouse]

We have a rather aggravating problem in our fuel system. Something is obstructing the fuel pick-up. This problem just made itself obvious, but I suspect it’s been coming on. On our spring cruise, we were changing Racor filters about every 8 hours. Also had to drain water two or three times. Yes, I know I should have been using a biocide ( let’s get the punishment phase over so we can move on.)
I haven’t been picking up much in the filter- random traces- of what looks like the jelly that the bacteria form, and the filter elements, while showing some fine dust, are not clogged according to the vacuum meter atop the Racor if the fuel line is disconnected. But once I connect the fuel line, the vacuum gauge quickly reads in the danger zone. Then the engine shuts down.
I’ve removed all the fuel, running it through the Racor then pouring it back via a Baja filter ( remember those?) The fuel is pretty cloudy, even though twice-filtered.
The cloudy situation came on pretty quickly. Before my last re-fueling, the fuel in the Racor’s plastic bowl was crystal clear. Now it’s really murky. Obviously my thought is contamination from the source. But I bought Highway diesel from a large volume service station, and though possible, it seems unlikely.
Something is obstructing the fuel pick-up. I have blown into the fuel line a few times. At first it seemed really obstructed, but after a little effort it seemed to clear, and the engine stared and ran for about half an hour, then it died of fuel starvation. Repeated the blowing trick, which seemed to cure it for a while, then fuel starvation kicked in and the cycle repeats.
So- what I do now? If it is an accumulation of bacteria gel, will Sea Foam or something at least liquify the gunk to a point of reasonable removal?

[LittleWing77]

Mickey,

Your fuel is dirty, plain and simple. Not only water, but sounds like an organic bug, now, too.

Proper fuel polishing would be my next step as well as cleaning the tank and fuel lines before the polished fuel goes back in.

Here's a simple explanatory article, but please note, I've no idea what "Aquafighter" is and it's obvious that Centre Tank Services is touting their own product.

At this point for you, I'm not advocating that you put in any futher additives nor buy something like their magical "Aquafighter".

What's needed now is to tackle this problem at the source. For future reference, you've got to catch this when it's perhaps just 'some' water (back when you were changing Racors every 8 hours or before); once you've got globs of organic jelly intermittently blocking your fuel pickup, you've gone past the point where any additive would solve the problem.

What Does Cloudy Diesel Fuel Mean
https://www.centretank.com/news/stor...n#.YZJK99lOl-E

Good luck and do let us know how you get on,
LittleWing77

[boatpoker]

Originally Posted by LittleWing77

Mickey,

Your fuel is dirty, plain and simple. Not only water, but sounds like an organic bug, now, too.

Proper fuel polishing would be my next step as well as cleaning the tank and fuel lines before the polished fuel goes back in.

Here's a simple explanatory article, but please note, I've no idea what "Aquafighter" is and I'm not advocating that you put in any futher additives at this point. No longer sounds as if additives would be useful. You've got to catch this sort of problem when it's just a bit of water (back when you were changing Racors every 8 hours); once you've got globs of organic jelly intermittently blocking your fuel pickup, you've gone past the point where any additive would solve the problem.

What Does Cloudy Diesel Fuel Mean
https://www.centretank.com/news/stor...n#.YZJK99lOl-E

Good luck and do let us know how you get on,
LittleWing77

What she said .....

[Bill O]

Will agree with the above comments about the dirty fuel and there must already be a good layer of water on the bottom of the tank.

If you don't have a clean out port, it may be time to install one to properly clean the tank walls of the goo build up.

You will want to remove all your fuel before cleaning the walls and the existing fuel should be polished if you are going to keep/reuse it.

Had an fuel "issues" before on a different boat where the pick up tube had a screen built into it. These can clog prematurely and should be removed, then depend on the Racor primary to do it's job.

Don't know what size Racor (micron) you are using for a primary, but maybe a good time to also change the secondary fuel filter (on the motor) after fixing the fuel contamination problem.

[mvweebles]

Good article from Steve D on additives that touches on tank-water. Describes a product that can be swabbed on end of a dipstick to detect presence of water.

https://stevedmarineconsulting.com/d...itives-part-i/

[MicHughV]

Some years ago, I put a new engine in my boat.
To do this required moving a diesel fuel tank first.

Being curious, I opened the inspection plate located on top of the tank to view inside.

I was amazed to see the bottom and lower sides covered in what looked like a black slimey goo...I'm going to guess....1/8 -3/16" thick...
I was fortunate that the pickup point for the fuel delivery system was about 2" above this level.

I've read several reasons for the cause of this, but removing it...none, besides hard labor. It would have to be scraped off and cleaned somehow....pressure washed most likely. The prospect of doing this seemed daunting to me. Without an inspection plate access, this would be next to impossible.

Considering my options, I had a new tank built.

[MicHughV]

I should add...that at the time or removal, that tank had seen 8-9 years of service, so clearly older tanks that have never been cleaned, would likely have a much worse problem.

[Auklet]

Last month we were motorsailing. The wind was getting up so I started backing off on the diesel to shut it down. It died suddenly and would not restart after several tries. We sailed into the harbor but I needed help from vessel assist to get into my slip. Fuel filter changes did not resolve. It seemed that something was blocking the pick up b/c no fuel was reaching the fuel pump. Burrowed down to the tank and removed the pick up. There, stuck in it, was a 5 mm long plug of some kind of firm jelly-like material. I pulled it out of course then pumped up the system, topping off the secondary at the engine, and got her running.

But, as I figured I would see this again, into the local fuel shop it went where they are all set up for fuel polishing and tank scouring. Polish the fuel (which isn’t much in a sailboat), install access ports, scrub and vacuum the tank inside, then refill. About 70-75% of a boat buck by the time you’re done. Don’t fight it. Just do it, maybe replace the fuel hose as well.

[Ziggy]

Originally Posted by Mickeyrouse

[...]Something is obstructing the fuel pick-up. I have blown into the fuel line a few times. At first it seemed really obstructed, but after a little effort it seemed to clear, and the engine stared and ran for about half an hour, then it died of fuel starvation. Repeated the blowing trick, which seemed to cure it for a while, then fuel starvation kicked in and the cycle repeats.
So- what I do now? If it is an accumulation of bacteria gel, will Sea Foam or something at least liquify the gunk to a point of reasonable removal?

Based on your description of the symptoms, I suspect there is a mesh screen at the inlet of the pickup tube. The screen collects the sludge from the tank and stops flow. Cleaning he pickup tube screen is often a lot more awkward than just replacing the cartridge in the Racor filter.


So in addition to cleaning the tank and fuel and regularly adding biocide, I suggest permanently removing the pickup tube screen.

[Manateeman]

As Littlewing77 posted, no magic additive is going to solve your problem.
Tank cleaners open the tanks and wash the interior walls with high pressure. We would not return any old diesel to a clean tank...period.
Lots of prior posts on new tank access ports.
Happy trails.
The manatee crew

[MicHughV]

I've seen engine setups, where two Racor filters were used and a switch between them, so fuel flow could be directed to either filter.

This might be an option, ie, you can keep the engine going, while the other filter element is removed and replaced, but getting the tank cleaned should be your primary goal.

[sck5]

I battled this exact problem for a while before finally biting the bullet and doing the following:

1. Your fuel is dirty. Get rid of it. No, dont filter it or clean it or add anything to it. It is contaminated with both biological crap and just plain crap. If you are tired of changing racors then dont recreate the problem by using the same fuel again. Pump it out and say goodbye and good riddance.

2. Remove the inspection port and fuel pickup from your tank and if there isnt an inspection port then either cut one, or replace the fuel tank, or resign yourself to changing Racors at an ever increasing rate forever.

3. Clean out the fuel tank until it is shiny clean

4. Do the same with the fuel pickup.

5. REPLACE THE FUEL HOSE FROM THE TANK TO THE RACOR AND THEN FROM THE RACOR TO THE ENGINE


Voila! Your fuel troubles are over and you can now put biocide in with every fill! (Or never put it in, I am in the "always" camp but the "never ever" camp has merit if you are certain you have a clean fuel supply)

PS Take the opportunity to mark your fuel gauge or measuring stick in 5 gallon increments as you refill your now clean tank with new fuel!

[Bill O]

Originally Posted by MicHughV

I've seen engine setups, where two Racor filters were used and a switch between them, so fuel flow could be directed to either filter.

This might be an option, ie, you can keep the engine going, while the other filter element is removed and replaced, but getting the tank cleaned should be your primary goal.

When I purchased our boat adding the second Racor was at the top of the list. Since we have two tanks it made more sense to add the second one so each tank had their own filter. As mentioned this allowed to switch fuel filters/tanks if they were starting to show a high vacuum. While I was changing the system I also added another valve to be able to direct the fuel return to either tank.

Originally Posted by sck5

I battled this exact problem for a while before finally biting the bullet and doing the following:

1. Your fuel is dirty. Get rid of it. No, dont filter it or clean it or add anything to it. It is contaminated with both biological crap and just plain crap. If you are tired of changing racors then dont recreate the problem by using the same fuel again. Pump it out and say goodbye and good riddance.

Depending on how much fuel we are talking about, there are other ways to not create a huge amount of waste product.

When I purchased our boat, I found the fuel tanks full (200+ gallons) which had been sitting in Michigan on the hard for several years. At that time, the fee for a fuel pump out/disposal was high as well as fuel prices and we were looking at well over $1k for the pump out and replace the fuel. With the knowledge that the Navy yard in Philadelphia (decades ago) had diesel powered battleships in mothballs, they polished the fuel and were still ready to go if needed, I made a simple polisher to clean up the fuel.

Using a Racor filter and an automotive fuel pump (with a pick up at the bottom of the tank), I pumped out each tank into 2-55 gal. drums to clean the fuel. We moved the boat 1,100nm with the old polished fuel (mostly motoring thru the Erie Canal and Hudson) and never clogged/needed to change a filter on the whole trip. (Just in case, I did add some cetane booster.)

At ~1 gal/min., it did take a while to pump out each tank. Since I was doing other things (and pumping out fuel at the same time), speed wasn't too much of a concern. I thought the simple "technology" worked well, but may not be for everyone.

[MicHughV]

I've been to places where diesel fuel delivery comes by truck or is pumped out of 45 gallon barrels.

With my own disbelieving eyes, I've seen some serious crud and slime come out of these transport sources. Bitching about it to the delivery personnel does little good.

Not having any kind of pre-fueling filter at the time, I had to resort to having 5 gallon plastic containers filled. These I could filter using a homemade concoction of an old t-shirt and paper towels in a funnel. It was a slow, laborious chore. I would leave about 2" of fuel remaining in the container so I could slosh out the crap after.

Fuel delivery in the US is likely very controlled, but once you leave these shores, you would be prudent in having some kind of pre-filter at hand such as the baha fllter or other types..which I've read do a remarkable job of ensuring clean fuel goes into your tank.

It goes without saying to carry a large number of spare filters, etc.

[AKA-None]

As I believe you mentioned water in the lines I would replace the o ring on the fuel filler cap