Click for Glendinning Click for Delta Click for Mulder Click for Walker Click for JetForums

Vessel shutting down engines

Discussion in 'Technical Discussion' started by MikeGT, Nov 25, 2016.

You need to be registered and signed in to view this content.
  1. MikeGT, Nov 25, 2016
    #1
    MikeGT

    MikeGT New Member

    Joined:
    Jun 18, 2016
    Messages:
    2
    Location:
    Torrance
    I have a 2008 Azimut 55 with CAT C12's (400 hours). I had an issue where one engine would suddenly power down and shut off on it's own (either one). I'd be cruising at about 1950 RPM's when suddenly the boat would turn sharply in one direction as one engine would shut down. I would bring down the throttle of both engines, place both in neutral, and could immediately start the one that shut down right back up with no problem. The CAT tech found nothing wrong with the engines and said there was a code showing that the vessel is shutting the engine down. The following weekend, after taking it out again and continuing on my 4 hour trip, either one of the engines would continue to shut down every 30 minutes or so at all speeds (was trying different speeds). The next time I took the boat out and ever since, no issue. The fuel looked clean and I was running with my fuel over half full. Sea conditions were smooth, weather nice. I'm at a loss. After taking a closer look at my survey when I bought the boat, I found this same error code about 100 hours ago (so previous owner had the same problem - yes I've reached out to him, but no reply).

    Since this occurred, I noticed that when running full speed, my port engine runs at 2250 RPM while the other runs at 2400. Not sure if this started recently or was doing this before the shut off incident. I was told that I might be "over-wheeled"? So, here is a theory: if my engines are running in sync, yet one is over wheeled, is it possible the vessel is sensing a problem with the sync and shutting down one of the engines?
    PS. I know Azimut is not one of the best boats in the world, but I love mine and will never part with her. Thanks in advance for any comments that could help me resolve this issue.
  2. Capt J, Nov 26, 2016
    #2
    Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,434
    Location:
    Fort Lauderdale
    You have to have the CAT tech look at the throttle signal codes.

    I'm guessing your issue is related to the sea fire shut down box, or a control issue. I had this issue and it was the sea fire shut down box and we confirmed it by looking at the throttle signal or throttle position display on the CAT laptop.
  3. Pascal, Nov 26, 2016
    #3
    Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,149
    Location:
    Miami, FL
    The only thing that could shut down the engines externally to the engines would be fire extinguishing system but I don't see how it would only shut down one engine

    I would start looking at a wiring issue. A loose ground wire can cause many issues including preventing an ecu from recording the proper codes

    You need to solve this quickly as shutting down a engine from high speed is not good for its health. As to the rpm issue if you were over propped both would be running below rated speed. I d start with the basics, look at the prop to make sure it s not damaged or doesn't have a line wrapped around. Then change fuel filters
  4. Capt J, Nov 26, 2016
    #4
    Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,434
    Location:
    Fort Lauderdale
    The more I think about it. The less I think it's the fire system auto shutdown as that generally will shut everything off all at once.

    I'm guessing it's leaning towards either the boats wiring for the ignition switches, which won't throw any computer codes. Or, it could be the engine controls. But, I'd lean more towards ignition wiring or switches.
  5. Pascal, Nov 26, 2016
    #5
    Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,149
    Location:
    Miami, FL
    Do you have remote start keys on the engines? If so try starting and running the engines from the engine room starters and see if it solves your problem.

    If it does then the problem is in the boat wiring
  6. CatTech, Nov 29, 2016
    #6
    CatTech

    CatTech New Member

    Joined:
    Sep 28, 2010
    Messages:
    56
    Location:
    south FL
    First a faulty throttle signal should not shut down the engine. loss of throttle input should default to idle RPM. A throttle code should be logged by the ECM's. With that said if the vessel is running at cruise and one engine defaults to idle it is possible the load will stall the engine.
    Now there are a few ways to shut the engine using what the ECM will consider normal and not store any codes. Key switch off, remote stop request and emergency stop request. (note some ecm's will store emergency stop request as unexpected engine shut down)
    Other things that will shut the engine off are loss of power or grounds( loss of power or ground should store a intermittent voltage code), fire system protection, loose connections at ECM, customer connector, battery terminals, starter terminals, power supply terminals.
    some commonly found issues are as stated the fire protection system, loose wires at the emergency stop button on the engine, azimuth tends to use the red and green start and stop buttons which are not very water protected the stop button may be sending a stop request to the engine.
    Are there any other electrical items shutting off at this time?
    Do the gauges continue to display accurate engine information during the shut down?
    Your initial post seems to indicate that both engines are doing this, if so start with common connection points of both engines for your checks.
    Intermittent electrical issues are difficult to troubleshoot.
    At the dock with engine running try wiggling the harnesses to cause the engine to shut down.
  7. wiredup, Dec 5, 2016
    #7
    wiredup

    wiredup Member

    Joined:
    Jul 20, 2016
    Messages:
    100
    Location:
    va beach
    Lots of good advice in this thread and wish I would have seen a thread like this back in the spring when my C18's were doing the same thing. It ended up being a ground wire at the engine. As mentioned, start the engines at the ignition on the engine itself. If all is good, then it is one of the above possibilities in CatTech's post causing the shutdown.
  8. Capt Ralph, Dec 5, 2016
    #8
    Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    12,726
    Location:
    Satsuma, FL
    What engine and throttle controls do you have. I finally straightened out a Teleflex/Mores KE-6 electronic control issue that similarly drove me crazy.
  9. Capt Ralph, Dec 5, 2016
    #9
    Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    12,726
    Location:
    Satsuma, FL
    The few and proud.
    Bless you and good luck.
  10. Marmot, Dec 6, 2016
    #10
    Marmot

    Marmot Senior Member

    Joined:
    May 20, 2007
    Messages:
    3,311
    Location:
    9114 S. Central Ave
    Are you saying a windmilling propeller increases the load on an idling engine to the point of an overload induced stall?
  11. Capt J, Dec 6, 2016
    #11
    Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,434
    Location:
    Fort Lauderdale
    What he's trying to say, is that when the engine goes to idle from cruise speed while the vessel and other engine is at cruise speed, the drag from the propellor may stall the engine with the sudden loss of rpm's causing it to shut down. I've seen it happen if someone cuts the throttle very quickly on only on engine. Rare, but I have seen it happen.
  12. Marmot, Dec 6, 2016
    #12
    Marmot

    Marmot Senior Member

    Joined:
    May 20, 2007
    Messages:
    3,311
    Location:
    9114 S. Central Ave
    He wrote "it is possible the load will stall the engine."

    What you have described is usually an issue related to poor transient response or fuel control linkage issues on mechanical or hydraulic governors.

    A windmilling prop produces negative torque ... it tends to drive the engine, not add load to it.