01 Launch - gas coming out of exhaust water??

The boat is running great...but when we start it there seems to be quite a bit of gas coming out of the exhaust and dispersing on the lake (not cool for the fish and swimmers). When it is just putting around/idling we can smell gas from the engine and the exhaust. We had the injectors cleaned and tested no problems.

There is a valve that comes out of the injector line and feeds into a hose that goes to the fuel water seperator, which then goes back into the exhaust water. Fuel seperator done? The valve from the injector line done? Could it be a leaky gasket?

Anyone have any experience with this? The boat still gets out of the water fine and runs fine but I think we are losing quite a bit of gas and $$$$. I have also noticed that the boat is starting harder and we need to slam the throttle in neutral to start it after it is warm.

Sorry for the essay but if anyone can help it sure beats taking the boat out for a week to get it hooked up to a computer.

My guess is cylinder(s) not firing, and/or injector(s) stuck open.

Too rich then and a start would be to check fuel pressure. LT and ST fuel trims will tell the story but that requires a scanner hook up.

There are no hoses that go from the fuel injection system into the exhaust. You do have a fuel return line though.

Hmm tricky,

If the injector was stuck open I'd expect it to run very roughly..

are you noticing any reduced power?

Peter:
There is a a valve that comes of the injectors and goes to the fuel return line, could that be screwed?

Brit Rider:
no reduction in power or rough running or idling.

Thanks

I don't know if this is the problem but if the engine is the Inmar EFI they sometimes have a problem with the injectors. The only way to tell is to have the dealer hook it up to the computer and it will tell you. Good Luck

Ryan,

Basically if you feel unburnt fuel is coming out the back something is majorly wrong... however for it to happen noticably there would be other signs like a cyinder not firing (a misfire would be obvious though and accompanied by rough running)... or revving higher than normal as more fuel is thrown in by a poor injector.

Could possibly be the injection system messed up a little but this is rare... the computer side normally just breaks in a big way on one or all cyclinders.

Take it to your dealer and have them plug the laptop in... it'll soon tell you if there's something wrong.

Found the problem last night.

The fuel return line runs into a black box(with water/gas separator on bottom) in the front of the engine, the box cools the gas with water before it runs back to the gas tank. When taking the water hoses off last night they were full of gas!

Somewhere in the system gas is leaking out, I guess that the gas lines are high pressure so it wouldn't take much of a leak to notice the gassy smell and gas on the water. We took the box apart and the coiled fuel line inside seemed intact but there was a thin o-ring floating around inside.

Our boat was the last year that indmar was using this system, so getting a new part may be a pain, the dealer said something about bypassing the cooling system and having the fuel go straight back into the gas tank from the fuel return line.

Anybody have any experience with this???

Thanks Again.

Ryan

That's a new one on me, but makes perfect sense. The fuel is entering your cooling water in the heat exchanger canister, and going thru the motor and out with the wet exhaust. Find which fitting that O-ring fell out of and repair / replace.

Just talked to the dealer again. He said to link the two water hoses together to bypass the cooling system, put it back together without the plastic shell on, run the boat and see where the gas is leaking from.

Question is, what is the best way to fix the leak, special sealant, tape of some sort, that the gas won't effect or rot etc...

Also, how important is it to have the gas being cool before it goes back into the tank?