Cool fuel problems

[chartersj]

Has anyone here had problem with their cool fuel modules? I just upgraded to a boat with an 07 496 ho and reading up on the cool fuel units it looks like most people have paint flaking inside the unit and restricting fuel flow, which in turn leans the motor out. I have yet to open mine up (bought the boat a few weeks ago and it is now -15 C outside) but I did pull the plugs to see what they look like. No hour meter on the boat but owner claims around 100hrs.. going to verify in the spring. But I have attached a couple pictures of all 8 plugs...do they look lean or normal?

 

[alldodge]

Don't see an issue with the plugs unless there is a runability issue

Paint in 496 Motors is under 2009-01 Bulletin and covers motors serial numbers 1A349420 and Below

 

[chartersj]

Don't see an issue with the plugs unless there is a runability issue

Paint in 496 Motors is under 2009-01 Bulletin and covers motors serial numbers 1A349420 and Below

It runs great on the hose, brought it up to temp and revved it a bit. Will need to wait a few more months before I can water test it. Just trying to read up as much info on these motors as I can. I may pull the fuel rails to look/clean inside as well. Also can you pull and inspect the injector basket filters to see if they are clogging up or are special tools needed?

 

[scoflaw]

Easiest place to look for paint is on the fuel pressure regulator that bolts to the CF3 module

 

[chartersj]

Easiest place to look for paint is on the fuel pressure regulator that bolts to the CF3 module

Ok thanks, I need to get a manual so I can find out what and where that is lol

 

[alldodge]

can you pull and inspect the injector basket filters to see if they are clogging up or are special tools needed?

Yes, and no special tools are needed. In the link below you can see the fuel rail, injectors and regulator. With pulling the injectors you could send them out for cleaning and flow testing

http://www.mercruiserparts.com/bam/subassembly/31825/11415/90

 

[chartersj]

Yes, and no special tools are needed. In the link below you can see the fuel rail, injectors and regulator. With pulling the injectors you could send them out for cleaning and flow testing

http://www.mercruiserparts.com/bam/subassembly/31825/11415/90

ok perfect, So does the fuel line from the cool fuel unit go to the regulator and then into the fuel rail? And i have been thinking i should have them cleaned and flow tested, This motor is new to me so id like to do a complete service and it seems like the fuel delivery is the only week point on these motors from what i have been reading

 

[alldodge]

Goes from cool fuel to the rail and the regulator bleeds off excess pressure back to the filter. The fuel pump can supply 60 psi pressure, but the regulator keeps it within specs

 

[chartersj]

Ok sounds good. I'm looking at service manuals would a diagnostic manual be good to buy as well?

 

[alldodge]

It could help at times but I would invest in a Rinda scanner (techmate Pro) or software (Diacom) after the service manual

http://www.rinda.com/marine/marine.htm

 

[chartersj]

It could help at times but I would invest in a Rinda scanner (techmate Pro) or software (Diacom) after the service manual

http://www.rinda.com/marine/marine.htm

Yeah probably a good idea,,, a shop down the road from me has a scanner as well that I can pop in anytime and scan it

 

[bman440440]

also if you get a computer diagnostic readout it will tell you the hours total and hours at the given RPM ranges

 

[chartersj]

also if you get a computer diagnostic readout it will tell you the hours total and hours at the given RPM ranges

Yeah would be nice to know that stuff, I will probably get my own eventually, working on re doing the whole interior and dash at the moment, that will take care of some beans

 

[chartersj]

So the merc fix is to replace the module with the newer one that has no paint inside. Can you just remove the paint from the one you have? also the plastic water hose fittings on the back side of mine have been doctored up with some silicone to stop them from leaking, could you pull the plastic fittings out and tap some treads in to put some barbed brass fittings it to hook the raw water hoses to?

 

[alldodge]

You could remove and try to get the paint out, but appears you also have the old fittings. The new module has tapped fittings and some have been able to tap the holes and all is good, others have had trouble afterwards. Guess it all depends on how bad it is when you get into it and skill set

 

[chartersj]

You could remove and try to get the paint out, but appears you also have the old fittings. The new module has tapped fittings and some have been able to tap the holes and all is good, others have had trouble afterwards. Guess it all depends on how bad it is when you get into it and skill set

Ok well i might as well try it then and see what happens, new modules are expensive

 

[scoflaw]

The flaking is only on the cover, take it off and have it bead blasted. Use the Merc plastic hose fittings if you tap it

 

[chartersj]

The flaking is only on the cover, take it off and have it bead blasted. Use the Merc plastic hose fittings if you tap it

Oh ok I thought the paint was through the whole module,,,,and why would you recommend using plastic over brass?

 

[alldodge]

recommend using plastic over brass?

I would say the housing is not very tick, and brass can be torqued enough to crack it. Plastic works just fine and is currently what is being used on new modules

 

[scoflaw]

Another weak link to that module is the very thin wall that separates the fuel chamber from the water, it can very easily corrode through