Could this mean I have water in my fuel?

[ReefRaider]

350 5.7 Mercruiser, 24' Trophy

Boat starts fine at dock. Instantly and easily. I take it out for a run, even short runs, turn it off and it won't start. It has to sit for awhile, sometimes a long while, and then fires right up again.

Several at the dock think I have water in my fuel. It "stabilizes" at rest, but with the boat in motion it mixes with the gas, causes above problem, and I have to wait for it to settle again. Kind of makes sense to me, but wouldn't the water still be in my lines after settling preventing the easy starts? And with the water at the bottom of my tank (below the gas) at rest, wouldn't it be picked up first? And how much water would I have to have to cause this?

This happened this past weekend and I haven't investigated yet. I obviously need to pull my fuel filters, etc. and check into it. Just thought I'd throw it out here first for some advice for when I do go down and troubleshoot. Thanks in advance.

 

[Don S]

Re: Could this mean I have water in my fuel?

It doesn't sound like water to me. Have you removed the fuel filter, poured it into a container and checked for water? That would be the first thing to do. And install a new filter, when you pour them out, you get dirt on the wrong side of the filter media.

When you say it won't start, does it crank over ok?

 

[ReefRaider]

Re: Could this mean I have water in my fuel?

Don, yes, it cranks over fine. But it acts like a no spark condition. But eventually, after sitting awhile, it fires right up. Yes, as mentioned, I need to pull / check my filter. Just wasn't sure if there was another theory beyond the water thing. You say it doesn't sound like it to you. Another thought I had was a bad connection somewhere (maybe the starter?). When cold, fires right up. After running, is something "heating up" causing the no fire condition until it cools down? Again, I need to investigate. Just thought if I threw it out here first someone may have had similar symptons and could give me another possibility. Thanks.

 

[ken_23434]

Re: Could this mean I have water in my fuel?

Check for spark when that happens. I have heard (never experienced, personally) that some times the coil will heat up and then no spark.

 

[zbnutcase]

Re: Could this mean I have water in my fuel?

Water is heavier than gas, so it settles at the bottom of the tank, meaning it would be picked up first after it sits awhile, pretty much kills that theory. And yes a coil can cause that, but it's fairly rare.

 

[tractoman]

Re: Could this mean I have water in my fuel?

Sounds electrical to me too. Coils do heat up and fail and then work again when they cool off. It's worth a check for spark when you are in the no start situation.