Random fuel issue Cummins 210

[Unclematt]

I have had this boat for 3 weeks now and have had three issues with the engine shutting off due to air in the fuel system. Today it ran perfect for 1-1/2 hours we anchored up for the afternoon then when I started the engine it ran for a few minutes and died. It restarted but you could tell it was not right. We left the anchorage and 10 minutes later it shut off air bound. I started to bleed it had fuel to the pump nothing to the injectors. The solenoid is working fine. Any thoughts? We had a Sea Tow ride home, the best investment I have made was my $165.00 membership. 2 hour tow was free the Captain was great and got a nice tip.

 

[Comodave]

I would go over the entire fuel system and check for leaks. Check all the filters and make sure that the filters are installed properly, gaskets and O rings in properly. Getting air in will kill a diesel quickly as you have found out, however the air leak may be very small and may or may not drip fuel. I would go over every connection with a fine tooth comb and redo any that look at all suspect. I replaced most of my port engine fuel feed and Racor filter this winter. I was very careful about sealing every connection. I went as far as using MarineTex on the metal connections very liberally. I know that I will never get them apart but it is only about $40 in fittings so no big deal. I have run the boat about 6 hours since we launched it and so far no problems. Good luck.

 

[sunchaser]

Umatt
How do you know it's air in the fuel? A piece of clear hose can help detect air bubbles.

Air in the fuel is certainly a possibility as Cdave suggests. A few other thoughts that may be of benefit:
- How full are the fuel tanks?
- How many hours did the vessel accumulate in the year or two before you bought it?
- Has any recent work on or around the fuel system been done?
- When was the last time all the fuel filters were changed?
- How old is the fuel?
- Do you have a vacuum gauge on the primary filter?
- Using a small fuel can, connect a temporary fuel line directly to the primary filter to eliminate possibility of air leak before the primary or problems with the tank pickup tube
- Finally, suspect stop solenoid and related circuitry or fuel pump, both easy fixes.

Do you have a smart mechanic around? Proper fuel delivery is diesel 101 for these guys. Good luck, great engine BTW.

 

[Unclematt]

I know there is air when I go to bleed it. My vacuum gauge is near zero when running I checked it just before the engine shut down. My tanks are full and the fuel is fresh. I have changed the Racor filters and they and the fuel were clean. I will be changing the engine filter today. I need to check the lift pump the hand pump on it is not working. My solenoid is working I checked that and the electric fuel pump works I use it when I bleed the system. I do have a good fuel guy and will call him if I don't get it sorted out.

 

[jleonard]

Check for output at the lift pump. I believe this model has a diaphragm style lift pump. I have had them go bad on truck Cummins

 

[sunchaser]

Umatt
Did the issue start after you changed the Racor filter?

 

[Ski in NC]

Put temporary clear lines on the supply side to the engine and the return side from the engine. Run engine and look for bubbles. An occasional tiny bubble or bubbles are sorta normal. Big bubbles are not, and will gag an engine.

But first things first: Got plenty of fuel in the tank? Tank valves lined up ok?

 

[rgano]

I once found a crimped o-ring under the tee-handle on a Racor as the cause of my port engine shutting down. Very early in the ownership of that boat, I installed a Facel fuel pump below the level of the tanks. In normal operation of the boat the pump was off and bypassed with a valve arrangement. When I needed to fill a Racor when the tanks were low or and engine or generator needed bleeding, I flipped the valve shut and powered up the Facet. It served to keep that port engine going for a month or more until i located the crimped o-ring. Do yourself a giant favor and install this capability.

 

[Unclematt]

The fuel problem showed up on our first trip which was bringing the boat from home Hyannis to Mt Hope Bay. we got it going by bleeding the **** out of it. The second time I was letting it warm up and it died and after extended bleeding I got it going. Last night was number three. I am heading out to do more diagnosing now.

 

[kapnd]

Check fuel flow from the tanks. Fresh and full doesn’t insure clean, there could be sludge in the tanks bottom preventing fuel outflow.
Another source of “loosing prime” can be malfunctioning check valve on fuel return lines, or return lines that are not submerged in the tank.