Merc Cool Fuel???

[SteveRay]

Can someone elaborate on this system and what it actually does? Why do people caution about them?
Also I have been hearing bad things about it lately and unfortunately our new boat is equipped with it. What should I look out for?

 

[rodbolt]

Re: Merc Cool Fuel???

its a marketing name.
instead of a vapor seperator merc runs the return fuel through a heat exchanger and back to the fuel water seperator to aid against vapor lock.
only thing is to be careful when changing the fuel filter as it may be pressurized and spray a bit of fuel

 

[SteveRay]

Re: Merc Cool Fuel???

ok so the fuel runs from port side through the exchanger, over to starbaord through the fuel water seperator, and then to the intake?
Any way to depressurize when changing filter?

 

[Don S]

Re: Merc Cool Fuel???

There is a schrader valve on the fuel rail. It's where you relieve the system pressure and also hook a fuel pressure gauge for testing.

 

[rodbolt]

Re: Merc Cool Fuel???

merc says let it sit 12 hours, or use the schrader or remove the fuel pump fuse and crank the engine.
I usually unplug the high pressure pump and start the engine and let it die.
on that system refilling the filter before installing it is almost mandatory.
otherwise it tends not to self prime.
its not a difficult system to work with. in fact it actually works well other than the pump is buried .