Atomic Diesel stalls after starting

[acudavid]

I bought a Catalina 30 a few months ago. It's original Atomic 4 was replaced with a Universal Diesel by a prior owner. Though I am not certain, I think it is a M-20 2cyl. Pre-purchase, we cruised around the harbor for about an hour and the motor sounded good to me. Post-purchase I had a lot of trouble starting the motor. I enlisted the help of a marina-mate, a lifelong sailor, who has worked on various diesel and gas engines for about 30 years. Once the motor was started, it would surge. We looked for a variety of air leaks, replaced most of the hoses, installed a second fuel pump and new fuel line in front of the fuel filter--replacing the outboard-style primer bulb and line, and of course, replaced the fuel filter too. As the problems persisted, he removed the high pressure fuel pump and inspected and tested it. We replaced both the injectors due to age and leaks. Some times the engine runs well for 30 or 40 minutes, with a slight surge usually present, and just this week it stalled and would not restart. There are no visible leaks of fuel. The batteries are good and all of the electrical system seems to be in working order.



Currently it starts and stalls right away. I have attached an audio clip and some pics in case someone can recognize.


The motor is too tall to fit in the standard engine compartment of the Cat 30. I was told it is a M18, but think maybe it is a M20

Currently, we are thinking the problem may be the fuel pump.

 

[JoeWhite]

Fuel tank screen clogged? Use a 5 gallon external tank and connect to the fuel filter and test.

 

[Don S/V ILLusion]

Old adage - diesels only need two things to run - air and fuel.

Do injectors spray consistently - need to remove and run pump

 

[odaydokay]

Second fuel pump? How about the other/first one? If is a Facet-style cylindrical, be sure to twist off the bottom and get the screen and magnet out and clean them up. I would also pump some fuel out of the tank into a container and have a good look at it. You could have sludge in there.

 

[Stu Jackson]

Fuel Starvation and The Obscure Check Ball Valve

Fuel Starvation and The Obscure Ball Check Valve

 

[acudavid]

Thanks to the excellent ideas from this forum, my mechanic and I went on a hunt for hidden sludge. We had already removed, inspected, and cleaned the high pressure pump and replaced both injectors. Today, we opened the main line from the fuel tank hoping to find a sludgy filter. Instead we found a loose fitting at the top of the tube which allowed air to enter the fuel system from inside the tank. We tightened the fitting, blead the fuel pump, then the injectors, and it started right up. It is still surging, but a big improvement. It's time to take it out motoring. I got my Boat US premium three days ago, so I hopefully can't get into too much trouble. I will keep the forum posted with developments. Thanks to all!

 

[acudavid]

I tried to take it out but the motor stalled and then would not restart. We replaced the fuel injector pump, added a 12 volt fuel pump and replaced the fuel filter, as well as both injectors. The fuel lines have either been replaced or look brand new.
I disconnected the fuel like from the fuel tank and inserted it into a small bottle with a quart of fresh diesel, blead the line, and it still is surging. 'The surging happens across the rpm spectrum.
We have looked for hidden valves and filters, but have found none. I plan to try a small external tank. Can I connect it directly to the fuel injector pump? Also, can I bleed with the bolt or do I have to bleed the injectors?

Follow up: I ran a large funnel into a rubber hose and clamped it to the fuel line directly into the injector pump, bypassing the 12 v pump, filter, and lines. I fastened to funnel to hang so gravity would feed the injector pump directly. The motor still surges. Could there be a problem with a governor?