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Mercruiser Gen III Cool Fuel Module

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troman9

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I just had my Mercruiser 5.0L MPI engine serviced. The mechanic found paint debris clogging the screen in what he called the "fuel cell", that is part of the Cool Fuel Module. He said that debris is a coating wearing off on the inside.

Seems strange that anything in contact with gas would be painted. I searched for forum posts describgin this problem,. I couldn't find any, but I did find that Mercury redesigned the Gen III Cool Fuel module in 2009 (supposedly to prevent corrosion on the cooling water ports).

Has anyone heard of this paint debris problem with the Gen III Mercruiser Cool Fuel module?
 
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If this is a problem with the units, I would think Merc is aware of it by now but I don't recall seeing any literature from them on this. Call them and enquire about it.
 
I have a 2006 34 sundancer w 8.1s. Had same issue w paint. They found it in
the regulators, fuel pumps, module, filters and injector screens totally clogged the entire
system. Apparently came from the fuel module. They appear to be painted on inside
and the fuel deteriorated it. All at a cost for both motors of over 4k.
Entire system was flushed and replaced. Mecruiser did have service bulletin but not for this
reason. They changed the water intakes to barbed and threaded. In my marina
alone there are 7 other boats with exactly the same issue
 
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Could ethanol have something to do with this/ I'm asking because I'm around a lot of these and have not come across this issue but up my way, we're not on corn gas.
 
jadilla said:
I bet that is exactly the problem, ethanol is nothing but corrisive.
Click to expand...


Perhaps ethanol is the problem. Long and short of it is that we have ethanol and it's here to stay. I plan on having my mechanic remove the fuel pumps on the new module to see if it's still "painted" or coated. If the ethanol is in fact creating this very expensive issue then there are going to be a lot of boats idled this season.
 
OK I just returned to this thread, and I had not seen the posts from April. Duke; thank you for weighing in, this is further confirmation of what my mechanic told me.

My engine ran fine for most of 2012, but last weekend my fuel burn was up again. This is what I was afraid of, and now it looks like I need to replace the entire fuel module. I called Mercury Marine back in January and even though it's clearly a manufacturing defect they wouldn't help me because the engine is out of warranty. So I guess it's coming out of my pocket.

So for future thread readers and any skeptical marine mechanics: yes Mercury Marine indeed painted the inside of these cool fuel modules and the paint comes off over time and clogs the fuel system.
 
Check the brass bypass plug on the engine side of the module. There is a check ball and a spring inside. When you remove the plug you will see that the spring has cut groves into the plug, when this happens it locks the spring down and the ball cannot move causing excessive pressure.
 
Yeah i see alot of these modules at my shop but in canada we don't have mandatory ethenol in our fuel yet so that may be what is causing this. With all the problems this corn fuel causes with boats i'm not looking foreward to seeing it either.
 
I realize this is an older post but I was just wondering if any of the techs out there think it would be a better idea to go with an after market fuel pump and filter?
 
troman9 said:
OK I just returned to this thread, and I had not seen the posts from April. Duke; thank you for weighing in, this is further confirmation of what my mechanic told me.

My engine ran fine for most of 2012, but last weekend my fuel burn was up again. This is what I was afraid of, and now it looks like I need to replace the entire fuel module. I called Mercury Marine back in January and even though it's clearly a manufacturing defect they wouldn't help me because the engine is out of warranty. So I guess it's coming out of my pocket.

So for future thread readers and any skeptical marine mechanics: yes Mercury Marine indeed painted the inside of these cool fuel modules and the paint comes off over time and clogs the fuel system.
Click to expand...

Im having a problem with one of my 496 engines, it is burning more fuel then the other one in the boat, and after a while running when I slow down it will shut off and be hard to start, it a most act like it is flooded. mine is a 2006 fountain with tin 496s
 
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