intermittent Engine Cutting Out

Discussion in 'Electronics Q&A' started by stu1, Jun 3, 2020.

  1. stu1

    stu1 New Member

    11
    Oct 23, 2016
    Loch Lomond, Scotland
    Sundancer 245, year 2007
    5l Mercruiser Bravo 3
    Hi, I am wondering if you could help me and my mercury mechanic in trying to fix an intermittent problem.

    My boat cuts out on me at irregular, obscure no pattern time. Its as if someone has gently turned the ignition key to off and when I restart the boat, it is as if nothing had ever happened. I can run it for 30 mins on idle one day then the next day it will cut off after 5/10 minutes and restart no problem. When running the boat, I can go on the plane no problem, no lack of power, perform up to 5k rpm then come off the plane and run at under 1k rpm it will or will not without any warning cut out. It has now become a major problem as my mooring is on a river which can run at times fast, so you can imagine my boat cutting out at the wrong time would be dangerous to everyone. The local mercury mechanic has done the following:

    • Regularly Serviced.

    • Replaced IAC Valve.

    • Replaced Fuel Pump / Regulator kit.

    • Replaced Crank Sensor.

    • Replaced Coil.

    • Cleaned Out Fuel Tank and Fuel System

    • Checked all wires for corrosion and being loose.


      Any help would be much appreciated as we are at a loss.


      Kind Regards


      Stuart Arthur
     
  2. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    What happens when you wiggle the ignition key?

    does it stall?
     
    stu1 likes this.
  3. stu1

    stu1 New Member

    11
    Oct 23, 2016
    Loch Lomond, Scotland
    Sundancer 245, year 2007
    5l Mercruiser Bravo 3
    Not tried that??? I will try that tomorrow.
     
  4. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    And not just the key, give everything the “wiggle test”, especially the wiring around the distributor.
     
  5. Greg Lions

    Greg Lions New Member

    5
    Mar 19, 2020
    Sydney Australia
    330 Sundancer 2009
    Twin 5.7 MerCruiser, DTS Vdrive
    Do your gauges do anything ( drop to zero/blank out ) when the issue occurs? If so could be low voltage - check/replace your alternator and or batteries.
     
  6. Searay Chuck

    Searay Chuck Member

    41
    Jan 8, 2008
    Buffalo. NY
    2000 410 Express
    Pilot Lounge
    Cummins 6CTA 8.3
    I would after you have checked for loose connections especially the main harness to the engine, check and replace the ignition module inside the distributor. I know it has been said that they either work or they don't but I have had this issue before as well as another person chasing the same problem and by replacing the module it solved the problem each time.
     
  7. Strecker25

    Strecker25 Well-Known Member

    Nov 20, 2014
    Rochester, NY
    1998 290 Sundancer
    Twin 5.7EFI/Alphas, Kohler 4kw
    Is it an alpha outdrive?

    Another member recommended I replace the shift interrupter switch as I had the same thing happen the other day on our port motor. Admittedly, I also replaced the alternator and coil because they were suspect but the gauges were bouncing like it was a very brief stall and then recovering. The thought was the interrupter switch was wacking out and causing the issue. Boat ran great after those 3 parts.
     

Share This Page

Show Sidebar