CF3 fuel regulator leak?

stephenm27

Active Member
Nov 3, 2009
526
Milton, GA
Boat Info
2021 Jeanneau NC 1095
Engines
2 x Yamaha F300
So, in preparing for a first outing of the season this evening, I found this disturbing fuel leak from the regulator on the CF3 fuel module (2009 350 MAG). My question is, has anyone experienced this before? Is this a common leak point? Is there more wrong than what I'm seeing?

Any insight/experience/wisdom greatly appreciated...thanks in advance!

Notes:
  • It's a very faint leak, but is definitely a leak.
  • Engines have not been run since last fall.
  • Ignitions were briefly on to raise the drives last night so I assume the fuel pump ran to pressurize the system.
  • I verified regulator retaining bolts are tight.
  • Boat is on trailer, stored indoors.
  • This CF3 module appears to have been updated by the PO as it does not have the problematic raw water hoses on the rear.



uc
 
In order to help those that may search this topic later...I'll post a reply to my own thread now that I've done some further investigation.

1. Removed CF3 paper filter cartridge, inspected cavity. Noted nothing abnormal, no flaking paint.
2. Removed CF3 fuel regulator (pictured above) and found large paint flake covering roughly 30% of the surface (see picture below).

Unsure of next steps but I'll probably start with calling Mercruiser to see if there's any assistance for this design fail. Any words of advice in this regard are welcomed. I know a few on the forum have been through the CF3 replacement process.


uc


uc
 
Looks like the classic “CF3 paint issue”

Mercruiser has been supplying a free replacement CF3 module to your local authorized repair shop and you will most likely be responsible for the labor.
 
Looks like the classic “CF3 paint issue”

Mercruiser has been supplying a free replacement CF3 module to your local authorized repair shop and you will most likely be responsible for the labor.

I've read Mercruiser has stepped up on occasion but not in many instances. Given that this module appears to have been replaced previously (as it doesn't have the original problematic raw water connections), I'm not sure they'd be inclined to replace it yet again--if in fact they actually covered the first replacement (previous owner).

Worse yet, MMax is my local "authorized" shop so there's likely $800 labor based on their typical rates, saving only a few hundred as new complete module is $1200. Installation seems straightforward--2 low voltage plugs, 2 raw water hoses, 1 high pressure fuel line, 1 low pressure fuel line.

As usual, it's really the inconvenience of the down time, especially at this time of year...
 
I just had mine done Sept 2018 on my 05 engine. Merc covered the cost of the replacement module and 8 fuel injectors. I had to pay the labor. Go to a certified merc mechanic and have them put in a claim. Merc knew about this since 2004. They will not do a recall, cost way too much money. But if you have an issue they will step up and cover the cost of the replacement parts.
Good Luck
 
I took the cover off mine and bead blasted the remaining paint off it. Worked fine after that. There is another fuel regulator on the fuel rail that has a screen in it that can trap paint. Monitor your pressure after you do this, if it's not correct, you will have to replace the regulator on the cf unit. The paint never made it to my injectors.

Real DIY repair, you could have this done in a day
 
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Like Scoflaw said, If you have the newly designed lower housing all you have to do is have the cover blasted to remove the paint. If your pumps and regulators on the fuel rail is fine your back in biz. Cheap fix. I primed the exterior of my cover as its aluminum.
 
I took the cover off mine and bead blasted the remaining paint off it...

Your comments re blasting the cover have me thinking that might be a better answer than an entirely new module. This engine has not shown any symptoms of problems. The ONLY thing that caught this problem was the detection of the faint leak at the CF3 regulator, so it's likely (hopefully) that no paint has made it downstream to the rail. And, the CF3 housing is most definitely the updated one so replacing it strictly on that basis isn't necessary.

I'm not intimately familiar with blasting but know what it is/what it's for/etc. I don't have a blaster, but Amazon does...anything so special about doing this that a $100 portable unit wouldn't suffice? Just pull the cover, clean, blast interior of paint, clean thoroughly, prime exterior of cover and replace?
 
I just had mine done Sept 2018 on my 05 engine. Merc covered the cost of the replacement module and 8 fuel injectors.
Good Luck

Were you having engine issues that caused you to involve them? That's my problem (I think). I caught this due to a leak around the regulator. I can't report any performance or running issues. In removing the CF3 regulator to investigate/replace it, I found the paint de-lamination shown above.

I could see how Mercruiser would side-step this one given they've not been proactive on addressing the issue--only reactive it seems when you experience resultant problems.
 
I took mine to a shop and had the covers blasted then replaced the lower housings as mine were the old model. Local shop did mine for free as it took him all of about 10 mins. I gave him other biz so it was pretty much 2 for one but i can't see it costing north of $50. See attached of the after. Goes without saying though that you should have a level of comfort dismantling and reassembling due the fact that you're messing with your highly flammable fuel system.
 

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I took mine to a shop and had the covers blasted then replaced the lower housings as mine were the old model. Local shop did mine for free as it took him all of about 10 mins. I gave him other biz so it was pretty much 2 for one but i can't see it costing north of $50. See attached of the after. Goes without saying though that you should have a level of comfort dismantling and reassembling due the fact that you're messing with your highly flammable fuel system.

Very nice work...thanks for sharing. At least I know what I need it to look like when I'm done now ;-).

Indeed, I'm comfortable (though appropriately cautious) working on this system. If only blasting the cover, I'm able to leave the housing installed, lessening some of the fuel line manipulation that has to occur with a new one. Backup plan is to just order the complete module and install it.

Sadly, it looks like the holiday weekend may be a casualty of the CF3...
 
Good info here. I have a 2008 6.2L. I am NOT having any issues at the moment but I want to do a little prevention before this happens to me.
I’m going to pull my fuel pressure regulator and see if I have paint flakes.
From what I’ve read it seems that the flakes issue is from the pump side(specifically the cover) than the filter side.

Great pictures in this post
 
I’m going to pull my fuel pressure regulator and see if I have paint flakes.
You may already know this, but be sure to relieve pressure in the fuel system prior to removing the regulator. I figured mine would have leaked down but there was residual pressure. Having a cloth draped over the area helped limit the pressurized spray, but if I had it to do over again, I would probably turn the engine over a few times after unplugging the pump (recommended in a few articles).
 
So the old CF3 module is out and on the bench. Here's a few pics of the internals. Estimated age of this unit is 5 to 8 years. It is not original (2009 boat) but was replaced sometime before end of 2015.

On the bright side, paint delamination appears limited to the regulator housing as well as the output port tunnel to the rigid fuel line. The pump cavity and filter cavity appear fine. Since the cover can be bead blasted and restored to a usable, paint-less condition, it looks like I'll have a backup module (or one to sell to a fellow CSR member in need).

I purchased a new CF3 to install as I didn't know what I'd find when I opened this one up...

uc


uc


uc
 
Thanks for the continued information on this topic. Great pictures.
 
I pulled my fuel pressure regulator today to check for paint chips thankfully there was none.
I’m going to continue to use premium gasoline with no ethanol and hope for the best.
 

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