Water in Fuel

[Jeff Spicoli]

Ok so early in the summer we took the boat out. Started fine idled out went to come on plane and the motor died, would turn over but not start. Went thru the whole fuel system, VST, Rails, all new filters. Really did not find anything that looked bad. The VST was clean no crud or anything. So I threw a Low pressure pump on. She cranked right up and ran great.

Now after about eight offshore runs it happened again. Boat launch cranks fine, fought strong current and docked, idle out to ICW and come on plane and it dies.

What I did this time. Cleaned all the electrical connections, pulled a spark plug to check spark, spark plug had some rust were it should not. Spark good. Drained the VST and what came out looked like cloudy vinegar with a definite separation between two liquids. So I hook up a aux. tank with clean fuel and try to flush out the contaminates. After about six times I tried to start, and she fires up. So I drain the VST and it looks worse. Drained in a mini bottle and about half of it separates, crank it a few more times repeat with the same results. WTF
Its almost like water from the cooling system is getting in the fuel system.
Oh and the last time she quit I just filled the tank with non ethanol, the fuel in the aux tank had the ethanol. ANY IDEAS?

[briscoe]

Did I read

Did you change your water separator filter?

[Jeff Spicoli]

The first time it happened yes. The second time no, but when I hooked up the aux fuel supply the fuel water separator was bypassed.

[catacom225]

Jeff! What size engine do you have, why don't you bypass the fuel cooling system then test to see if thats where your problem is

[artdf175]

water will sit in the bottom of the fuel tank and can be mixed with fuel as are traveling
take a quart jar and pump gas from the tank directly onto the jar and see what you get
also can take the water/fuel filter out and dump into glass container to see if it has water
if you have much water on the fuel tank it is a real pain to get it all out
Art

[catacom225]

Hey Art! Logics would suggest that hes got a load of water sitting on the bottom of his tank or he filled up on bad fuel but He says that he ran it on a seperate tank with fresh fuel and bypassed the seperator and it got worst,I'm not sure if the VST is cooled

[Moonlighter]

There is no way that I know of that water from the cooling system can get into the fuel system so that it gets into the supply before the VST.

The OP must have water in his fuel tank. Inline filters such as the RACOR's can only collect so much water, when they are full, water gets to the engine.

OP Needs to take action to get all the water out of the tank. And then figure out how it is getting in so it doesnt happen again. Art is right, it needs to be pumped out completely, or at the very least the boat tilted up on a steep angle so that the water can gather at the back of the tank, if you can then get a hose into the back corner and pump a few gallons out you will soon see if water is in there.

And then do a complete clean out of the fuel system from the tank to filter and thru to fuel pumps, the VST and rails. I would look closely at the lp and hp fuel pumps, water can cause internal corrosion, esecially if somehow salt water is involved - we had a member of our fishing club who had salt water getting into tank via a badly positioned breather fitting and man, it destroyed those pumps.

Ethanol fuel is IMO bad stuff in the marine environment. It can absorb a certain % of water due tits alcohol content but the moment it gets past the critical %, it phase separates and ALL the water and fuel is then sitting in separate layers. Once that happens, the whole tank full is no longer useable and needs to be disposed of, the remaining fuel is un-useable.

[catacom225]

Moonlighter, I am with you all the way, the chances of a bad rail is so remote its not funny. In saying that he stats that he has run the engine on a spare tank, firstly on ethenol then resorted to straight gas and still getting water in his VST, so unless he's pumping water straight from the bowser or pump . He says the water is in the VST, now if were talking water in the bore then thats something else . First thing i would do is change service stations

[Moonlighter]

The way I read his post, after it hapened the second time, all he did was drain the VST and then hooked up the aux tank in the hope it would flush out the system.

But the fuel lines between where he connected the aux and the LP fuel pump was probably still full of water from the main tank. Which again ends up in the VST and engine filters and parts before and after it again.

I would say it is likely to have a big load of water in the main tank and, probably, associated trash in the tank, lines, primer bulb, filters - you get my drift, most likely the whole fuel system is water/debris contaminated. Never going to fix that by just fixing one bit of it, IMO the best and most methodical approach if you really want to fix this properly is to clean the whole "fuel system". From Tank to injectors.

Every time I have seen water in ethanol fuel it has also had other debris and junk in it as well. It makes the cleanup job more complicated than just draining things out and then using fresh fuel.

Re the gas station - yes, most likely culprit, along with a fuel filler cap with a failed seal, or water leaking onto the top of the gas tank under the floor and then pooling around the tank fitting connections and getting in thru there. Or, somehow getting in thru a breather fitting.

You can get an excellent "Mr Funnel" that will quickly separate out water from fuel as you fill the boat's tank. Lots of people I know use them to put the first gallon or two in the tank when they fill up, if there's any water in there it will be caught in the funnel - if not, they figure they are pretty safe to continue filling direct into the tank. If they DO find water then they are straight in to talk turkey with the gas station operator, with the evidence in their hands!

It also does worry me that he reported a spark plug with signs of rust. Would so much water be getting thru the injectors to cause that????? Or is there another reason??

[Hoosmatroos]

It also does worry me that he reported a spark plug with signs of rust. Would so much water be getting thru the injectors to cause that????? Or is there another reason??

+1. Rust on plugs where it shouldn't been.

[Jeff Spicoli]

Hey thanks for all the help. I forgot to mention that the engine is a 2007 df175. What really puzzles me is that when I got the boat to run on the aux. fuel supply with the water fuel separator bypassed I ran the boat for about 10 minutes. I would have thought all the water would have been flushed out. Then like I said I drained the VST into a small bottle and half of what was in the bottle separated. The boat sat for a month when it stopped before I could work on it. I think the plugs had enough water in the combustion chamber to cause the rust. I also was not aware the cap could leak water into the tank, the boat was outside in Jacksonville, FL. when hurricane came through.
Next step clean tank and install new hose, and a new larger water separator. I am also worried about the HP pump, its like 300.00 bucks

[Murray]

I purchased a boat that hadn't run for 3 years, the fuel was the colour of a dark amber ale. To drain the tank i disconnected the fuel line at the engine, separated the fuel line from wiring harness grommet and used the primer bulb to start the syphon. The fuel line was too short to reach the ground so I slid a piece of clear plastic hose over the discharge end of the fuel line to reach the Jerry can sitting on the ground. Once drained I added about 10 litres of fuel with a good dose of Seafoam and syphoned that 10 litres out. Did that twice, the second time the fuel was wasn't perfectly clear but much better. The fuel from the first syphon went to an old Jerry can and is being used as a parts cleaner, the fuel from the subsequent syphons went into the truck. I wasn't dealing with water, just old fuel. It seems boat manufacturers like to tuck the fuel tank in the hardest most difficult place to get at making a visual inspection a challenge.