Volvo MD11CC loses power when under load, eventually dies.

[jashenderson]

My Volvo MD11C began losing power when motoring in heavy seas. It eventually cut out. I changed the primary fuel filter and bled the lines. It ran for a while and then eventually died out. Now won't start. Any advice??

Jim Henderson

 

[Dalliance]

Is fuel still getting to the injectors?

 

[jashenderson]

I think so. I loosend the nut and fuel came out.

 

[michael_w]

Crap in the fuel lines upstream of the filters. Might be letting through enough fuel to idle the engine but not enough when revved.

I've had the same problem on 3 boats and a Land Rover. Clean out with a bit of wire and compressed air.

 

[jashenderson]

Thanks for the response. I had to leave the boat in Maine. I'm in Boston. I'm going up today to see what I can do. I have a new fuel pump I think I'll install.

 

[RivalRedwing]

Sounds like gunge in the tank - the only permanent fix is to empty the tank and clean it out. If you see no debris in your old filter then you may have a crude filter at the point of exit of the fuel pipe from the tank (inside the tank) which is blocking.

 

[jashenderson]

Thanks.

 

[jeremyshaw]

"motoring in heavy seas" is surely the clue here. I've known several boats have problems with fuel gunge stirred up as a result, as other posters have said. So by all means change the fuel pump, but I'm not sure that will do the trick.

If the boat is old then it is worth getting the fuel polished - I'd think in Maine you can get someone to do that. Otherwise it will only happen again. Diesel bug is one cause of this, and even if you put bug killer in then you get dead bugs! And of course just general crud and dust over the years.

If you can, try shutting off the fuel supply at the tank and disconnecting the hose to the primary filter. Then turn hose back on and see if you get decent flow. If you don't then the tank screen is blocked. Happened to me and took a deal of blowing to clear it (not of course that I could possibly advise you to do that). Let's hope you have decent inspection hatches on your tank - I wish I did.

BTW you didn't mention changing the secondary filter if you have one....

Worth being sure you have this fully sorted as it's in the worst of weather it will happen again otherwise of course!

 

[pvb]

Also check...

A number of builders use Volvo Penta fuel system components when installing VP engines. The VP fuel tank pick-up pipe has a fine mesh strainer on the end - see here for a pic of it. This can get contaminated with gunge and cause fuel starvation.

 

[charles_reed]

Almost certainly gunge

in the tank.

The only real cure is to have the tank out and steam-cleaned - which I did after 3 years of making-do, as recommended by other posters

 

[jashenderson]

Re: Almost certainly gunge

Thanks to all who rersponded. I replaced the fuel pump and pressure blew back into the tank that hopefully dislodged the gunge. Ran engine for 12 hours motoring from Maine to Boston. Engine ran fine. Have to pull the engine to get at the tank. The photo of the volvo fuel pick up was particularily helpful

 

[pvb]

Before you do that...

[ QUOTE ]
... Have to pull the engine to get at the tank. ....

[/ QUOTE ]That's pretty extreme. Before you do that, you might consider some fuel polishing. It would be a lot cheaper, and would most likely remove most of the contaminants in the tank.

 

[jashenderson]

Re: Before you do that...

What's fuel polishing?

 

[pvb]

Fuel polishing...

Fuel polishing involves pumping the diesel out of the tank, through a filter, and back into the tank. Running such a system for a reasonable period will help to remove a lot of contaminant from the tank.

There are companies which offer the service, using mobile equipment. Take a look at the PowerSure website as an example - they're in Boston, but may be able to travel to your boat (or recommend another operator).

You can also make your own fuel polishing system using a suitable pump and a filter. The secret to success is getting at the crud at the bottom of the tank - sometimes it's possible to use a rigid suction tube to "hoover" the crud off the bottom of the tank. In many cases, though, baffles restrict access. One other way of getting the crud stirred up is to put the filtered fuel into 20litre containers and then tip it back into the tank as quickly as possible. That's what I ended up doing when I needed to clean up my keel tank (under the engine).

 

[jashenderson]

Re: Fuel polishing...

I googled PowerSure but nothing came up. Is there another name?

 

[BrendanS]

Re: Fuel polishing...

The link to the website is in the post you replied to, you just need to click on it.

 

[pvb]

Re: Fuel polishing...

Yes, as Brendan said, it's a clickable link. The URL is www.powersurefuel.com