Cool Fuel module problems 350 MAG

[Tblokhus]

My boat starts no prob. It runs well at high speed 3500RPM. When going to a low rpm for 20 min it stalls and will not start. After 45 min or so it starts perfect.

The water tubes going into the Cool fuel module are dirty.

So I expect then cool fuel module causes the fault.
Any other suggestion?

 

[Espos4]

Where are you located?

A 275 Sundancer sounds like possibly Europe?

 

[paulswagelock]

Some specifics about your engine, year, drive type etc. would be helpful.
Before investing in a cf module, be sure to check fuel pressure at the rail when it is running fine, and then when it won’t start. Need to do some troubleshooting.

 

[Tblokhus]

Yes I am located in Denmark the 275 is the Europe version of the 260.

the boat is a 2005 equipped with a 350mag mpi with a bravo 3

was out sailing for a few hours no problems, we went down a bout 1000 rpm for about 15 min when the motor stoped and could not start again.
The same thing accuses the day after.

when trying to start there come some
Noise form the CF. And it Is warm.

The IAC value has been changed.

as mentioned the cooling water hose that goes in to the cf has a lot salt/ white dirt i them.

 

[paulswagelock]

First diagnostic - when it dies, check the fuel pressure at the fuel rail. If it is not 40 psi or so, then there is something up with the cf module, or the power circuit feeding it. If there is fuel pressure on the rail, problem is something ignition related.

 

[Tblokhus]

Is there a Schrader valve to connect the fuel pressure tester ? I cant find it?
However the Fuel module get hot when running, so that why I am expecting the CF to be the problem.

 

[paulswagelock]

Without knowing your serial number, I guessed it and looked up the part. Schrader valve looks to be on the fuel rail in the section that connects the left to the right 2/3 back the engine.

 

[Seapig]

I’m suspicious that you may not have a cool-fuel module and you are mistaking the fuel pump for a cool-fuel module. I had a 2005 260 with a MAG 350 and Bravo 3 and it did not have cool-fuel. If it’s about the size of a beer can with Only 2 metal fuel lines attached, it’s just a fuel pump and will get warm normally.

 

[scoflaw]

If its on the port side it's a CF2, if it's on the stb. side it's a CF3. Both have a shrader valve on the rail

 

[Tblokhus]

I have a CF3 the old part # 864650A05 got replaced with 8M0047215
Problem is that the connectores to the CF is broken, So not sure if I can start the motor without cooling the Fuel Module for testing of the Fuel pressure.

Normal the Motor has to run for about 15min with low RPM before the motor stops

 

[Tblokhus]

If its on the port side it's a CF2, if it's on the stb. side it's a CF3. Both have a shrader valve on the rail

I found the Shrader Value, the CF in om the starboard side.

 

[Tblokhus]

I

Without knowing your serial number, I guessed it and looked up the part. Schrader valve looks to be on the fuel rail in the section that connects the left to the right 2/3 back the engine.

I found the Schrader Valve thanks.

problem is that the connectores to the CF is broken. So not sure if I can start the Engine with out cooling the CF. normally it has to run for about 15min low RPM before it stalls.

 

[scoflaw]

Fix your leak first.

 

[Tblokhus]

Fix your leak first.

There is not leak to be fixed. it about the engine stopping.

 

[scoflaw]

Post 10 says you have a broken water fitting.

 

[Tblokhus]

Ahh it just the hose going into the CF. I try to fix that whit a fitting.

 

[Tblokhus]

An update form Denmark and my engine problems.

I do not have a fuel pressure gauge, but tried to turn the ignition and them press the Schrader Valve. A little fountain of fuel where coming out.

I then started the engine, and had I running for about 15min before it stalled. I happened to get it on video, as the sound of the engine started to sound different.

I then turned the ignition on again and no fuel was coming out of the Schrader Valve . It did sound like a little air release but no fuel.
I recorded the sound of the pressure building up. is sounds very diffrent from normal.

After 20min or so I could start the engine again. I recorded and there is a different in the sound of the pressure building up.
And a nice fountain of fuel was coming out the Schrader Valve.

The electric connector to the CF got warm, but it sounded like they were still delivering power, as there was noise from the CF, when I turned the ignition on.

I have all diffrent sound on video, but I can not upload video to the forum.

 

[keith akridge]

My 220 select (1700hrs) does the exact same thing. 5.0 mercruiser, bravo 3 drive with gen III cool fuel module. After idling around for 15 minutes or so the engine starts to run rough & eventually dies & wont restart for 20 minutes or so. After 2 times I figured out the fuel pressure was dropping below 40psig & the fuel module was getting extremely hot causing a vapor lock issue or pumping issue. So at idle my water pressure is on 2 psig or so, at speed its up to 9 psig. I currently have my fuel module out of boat & the water passage side is soaking in barnacle buster to clean it up for maximum cooling. Contacted mercury & they replaced my injectors & fuel pressure regulator housing due to the paint on the inside starting to delaminate also, this is another common problem with the earlier gen III fuel modules.

 

[Tblokhus]

Did it help changing the CF? I have ordered a new module.

how old is you engine? So far I have not been so lucky that Mercury will replace any parts.

 

[keith akridge]

I haven't had a chance to take mine out since I worked on it. My engine is 2007 original with 1700hrs