Clogged Fuel Pickup, Diesel

[jimmcgee]

Two weekends ago we were sailing in choppy conditions on the bay. When I fired up the engine to drop the sails she ran for a few minutes then died. She'd restart and die again. I could hear she was starving for fuel. I threw out the anchor and after getting bounced around the cabin for a while trying to change filters decided to call TowBoatUS.

Last weekend I bit the bullet and pumped my tank out. I was concerned about gunk in the bottom as this has happened before after being out in choppy conditions.

I found gunk on the bottom of the tank as expected. The fuel was clean -no water, no growth.

What really shocked me was the clog in the fuel pickup. I've seen posts about removing the screens on the pickup in Catalina fuel tanks. Now I understand why. The screen was pushed about two inches up the intake pipe (P.O.?). From the screen down was two inches of crust and goo. It didn't take much additional crud stirred up in the fuel to clog the intake. After a while it would settle back out and the engine would run fine - until you were in choppy conditions again. Given how much crud was in the pickup I'm amazed it ran at all!

The fuel inlet is the forward most hose coming off your tank. On my boat there is a fuel shutoff on the fitting. I'd absolutely second the recommendations of others who've posted about removing the filter. It's easy to remove the pipe from the elbow and push the filter out with a coat hanger. Any gunk that would've caught in the screen will be caught by your primary 30 micron filter -- which has a hell of a lot more filter surface than the screen.

I'm just glad it clogged where I could throw out an anchor without endangering boat or crew.

Jim
95 C30 Island Time
Barnegat Bay

 

[Anonymous 121765]

Jim,

You hit on a common problem. The fuel tank w/clog will fail at the worst possible times.

On my 1980 C30, I decided to cut a square 6"x6" hole in the tank top.
I had quite abit of sludge and hand cleaned it out. I cut a 7"x7" alum. cover plate, and for gasketing, I used butyl rubber.

I removed the useless screen and have not a problem since. I installed a ball-type valve in the hatch at the companionway foot and this works well when changing filters especially underway. Also less priming with this setup.

What is important after having a clean tank is to use ONLY highly filtered fuel. I NEVER use fuel from a marina or fuel dock, but jerry can it myself. Find a top brand name gas station and look for diesel that is clear, like water. Diesel, highly filtered is also used as aviation fuel. Many planes run on diesel. If there is a color/tint to the fuel, do not use it. Exxon stations have well filtered fuel.

For changing filters, the low point valve will keep the hose to your primary filter primed. Don't crack the vent open, leave it closed. I keep an extra small bottle on hand with fuel for topping off the fuel in the primary. With the valve closeed, drop the new filter in, & fill the housing with the extra fuel in the bottle. On the secondary filter, leave the vent closed and remove the old filter. Take the extra bottle of fuel and fill the new filter. Just screw it in.

On older model engines, you may need to bleed the secondary also. My newer 3M20A does not require this. You will need to see what works best for your engine. It seems newer engines with a common fuel bleed at the injectors need less priming with my procedure.

You will find that most times, after three tries your engine will start. It will be a bit rocky at first, but any air in the lines is quickly sent thru your return back to the tank.

Changing filters will be a piece of cake, and a clean tank w/fuel should remain trouble free. Remember to keep your tank at least 3/4 full, as this allows for less moisture buildup. Use your fuel in a timely manner, so no breakdown in fuel quality.

Good luck,

CR

 

[DanM]

Ron,

All good advice and I like the idea of the easy to access shut off valve for filter change under way.

I've been in aviation most of my life though and have never heard of using diesel fuel in an aircraft engine. Perhaps you are refering to the kerosene like smell of jet fuel?

Take care, DanM.

 

[jimmcgee]

Ron,
With my '95 I just fill the new filter with fuel and start it up. The system is supposed to be self bleeding. She'll be a little rough for a minute then smooth out.

What shocked me was how much crud was accumulated in the pickup. I was also surprised there are no baffles in the tank.

This weekend I'll finish cleaning it out as best as I can to get me through the season -- that is if Irene cooperates.

I'll pull the tank over the winter and have a radiator shop steam it out. If she looks solid I'm going to take your advice and add an access panel in the top of the tank for seasonal cleaning.

Jim

 

[jimmcgee]

Ron,

All good advice and I like the idea of the easy to access shut off valve for filter change under way.

Take care, DanM.

The best system I've seen for changes underway Filter Boss

Not cheap though...

 

[Bob S]

Jim,

After reading a lot post on problems with dirty fuel and being a rookie I decided to cut an access hole in mine. I was actually surprised to see how clean mine was. Now I remove the fuel at the end of the season, leave the port open and wipe it clean with white cotton rags and denatured alcohol. The thought of loosing my engine in rough seas scared me. So what ya think happened to me last month! I lost my fuel pump. Go figure.

I'd cut an access hole and see if you can clean it yourself before pulling the tank out.

 

[jrowan]

I can also testify to loosing my engine right when I needed it several times when going out in a TIGHT channel due to a clogged fuel filter screen at the fuel pickup tube in the tank. Those screens should be illegal. How anyone thought that an inaccessible screen like that was a good idea is beyond me. My troubles were with a supposedly better built S 2 with a Yanmar diesel. It was amazing that the mechanical fuel pump could get anything through that clog at all. Built in low tech fuel saving device? Since the engine stalls out, hence it uses no fuel! hah.

 

[DanM]

Man, why does it always happen in the tight channel!? That's right where it happened to me!

I cut an access port into my fuel tank and cleaned it out, removed the pickup tube screen, new fuel lines (my 25 year old lines were pretty brittle), and am cautious with using clean fuel and a biocide. (I've used BiorborJF with good results for about 7 years so far).

In these pictures you can see my very low tech inspection port. I just used a four inch hole saw to cut the hole. No matter how much I cleaned and vaccumed that tank out though I still had a couple of shavings in my Racor filter on the next filter change. Be very careful with you shavings!

Oh, and don't forget that if you have the Facet electric fuel pump there is a screen that needs to be cleaned in there, and it's not a really obvious screen, you have to look for it a bit.

Also, I stuffed my camera in there to get a good look in the lowest corner of the tank and that is what the other picture is. You can see the pitting in the walls of the tank where water had sat for years I'm sure. This is where the pinhole leaks are probably going to start at some point like so many owners have had to deal with on the older boats.

Take care, DanM.

 

[Inter20sailor]

I like the idea of cutting an access port in the tank. This is going to be my winter project. However, while I am cutting such an access port, has anyone installed, or rigged a 'sight gauge' on the side of the tank? I am very suspect of the accuracy of the fuel quantity gauge. (I don't rely on it, I use time and gallons on a sheet to figure my burn rate out)

Also, I have heard of people changing the tank out with a heavy duty plastic tank to eliminate any type of rust/ corrosion problems. Anyone out there done this?

Thanks

 

[jimmcgee]

Well with Irene coming in there was no thought of cutting inspection ports. I had pumped the fuel in the tank into two five gallon jugs. There was some sediment accumulated on the bottom of the second jug (fuel from the bottom of the tank). So I poured the five gallons of clean fuel in, buttoned her up and hit the key.

She fired right up, smoothed out after a couple seconds and is running smoother than she has since I've had her.

I let her idle for a good 15 minutes before heading over to the haul out. I'll add a little fuel as needed to get through the season, then do an R&R of the tank for cleaning and the installation of an inspection port over the winter. If there's any sign of corrosion under the tank or the start of pin holes I'll replace it with a new tank from Catalina Direct.

This weekend will be the real test.

Hope everyone came through the storm OK,
Jim

 

[Inter20sailor]

Before I go cutting the top of my tank open, are there any internal bulkheads in the tank?

 

[Anonymous 121765]

Inter,

If you have the 18 or 23 gallon tank, there shouldn't be any baffles.
To be sure pop out the gauge fitting. Take a hanger bend it in the middle somewhere and probe the inside first.

CR

 

[Inter20sailor]

Dumb Question:

I will syphon the tank out as best I can, but it will be assumed that there will be a small amount of fuel on the bottom. When I start cutting with a saw, must I worry about heat and fumes? Obviously, diesel is not as volatile as gas, but should I fill the tank with water for a safety precaution?

 

[Anonymous 121765]

I20,

IT TAKES ALOT TO SPARK DIESEL. Get a cheap hand pump that you can connect a hose on and you will be fine pumping the last bit of fuel out if you want.

If your using a saber saw or large hole saw, you shouldn't have a problem. Aluminum is less likely to spark that steel. I cut my hole (rectangular) outer edge closer to the edges about 2 inches in from the sides. This will give you more support for a close-off plate when done.

If you are going thru with this effort, make sure the hole is big enough to easily get you hand in for any future cleaning/inspection. Be careful drilling holes for the close-off bolts as you will need a good fit if using sheet metal screws. Find some 1/4" thick Buna-n rubber gasket to size for the cover and you're done.

Let me know how it goes pal..

CR

 

[jrowan]

The last thing in the world I would want to voluntarily do is introduce water into my fuel tank. If any water condensated up into the fuel pickup or it wasn't very thoroughly cleaned out the results would be didastrous to the fuel injectors & pump. Also I agree with Ron; I knew an old navy veteran who told me that they used to put out cigarette butts into open barrels of diesel oil without any problem/explosion. Not something I would recommend! but it proves the point of diesel's low octane volatility.

 

[Stu Jackson]

Gentlemen,

I have been linking to our C34 Critical Upgrades main message board topic on this forum for a long time. Perhaps some of you haven't seen it yet. We wrote it to avoid you all having these same problems and reinventing the wheel. I continue to share it with M25 series engine owners and will continue to do so. Perhaps you can help me spread the word.

http://c34.org/bbs/index.php/topic,5078.0.html

Thanks and good luck.