Mercruiser 3.0L 1995 stalls after 1 min

Discussion in 'Gas Engines' started by wmoss, Jul 19, 2007.

  1. wmoss
    Joined: Jul 2007
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    Location: Pittsburgh, PA, US

    wmoss Junior Member

    Hello All:

    I would greatly appreciate some advice in troubleshooting a problem with my boat:

    1995 Mercruiser I/O 3.0L Alpha1 Electronic Ignition, carb

    Running 1/2 throttle one day and the engine bogged, then stalled. Started right back up, ran 30 seconds, then bogged & stalled again. Started right back up, ran 10 seconds, stalled. This repeated all the way to the dock (made for a real fun afternoon).

    When I got to the dock, I removed and cleaned the fuel filters in the carb and fuel pump. both were pretty dirty, so I thought I had solved the problem, but no such luck. Fule level was pretty low when this happened (1/8 tank), so I suspected bad fuel. Filled the tank with new gas and ran through for a while, same problem. Checked plugs, looked really carboned up, so I changed them...no effect.

    When it its cold, it will start right away and run 1-2 mins then stall, After that, it will run only 10-20 seconds then stall.

    Any recommendations for my next trobleshooting step? Any help is greatly appreciated.
     
  2. USCGRET/E8
    Joined: Jul 2007
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    USCGRET/E8 Senior Chief

    Sounds a bit like water in the gas. But if the filters where dirty, most likely some of the finer dirt is now up in the carb, clogging the smaller idle jets.
    Clean the carb and get a bigger/better inline fuel filter. I like the kind that allows you to see inside and also separates any water. The water will be visable and you'll know when to clean the filter.
     
  3. wmoss
    Joined: Jul 2007
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    Location: Pittsburgh, PA, US

    wmoss Junior Member

    Thank you USCGRET/E8. I will proceed as directed.
     
  4. TerryKing
    Joined: Feb 2007
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    Location: Topsham, Vermont

    TerryKing On The Water SOON

    Shooting Trouble

    Hmmm. You need to differentiate between fuel and ignition problems, I think.
    Although it SOUNDS like fuel...

    When it 'stalls' is it an abrupt cut out, or are there several misfires and rough running before it stops?? Abrupt sounds more like ignition, otherwise fuel/mixture.

    Two old tricks.. Run a 'spark tester' (they used to have a neon lamp and go in series with a spark plug) so you can see if spark stops before the engine does.. Second, right after a stall, immediately pull a couple of plugs and see if you can see any water droplets or funny stuff..

    Did you add any "dry gas" to the tank?? Water stays at the bottom where the fuel is picked up...

    I like the glass-sided filters too; I have one just before and just after my fuel pump so I can see what's happening.

    Let us know what you find!! More more data point for the next time...
     
  5. wmoss
    Joined: Jul 2007
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    Location: Pittsburgh, PA, US

    wmoss Junior Member

    Thank you Terry. Stall is pretty abrupt and it has never misfired/backfired. I will see what I can rig up to test the spark. And so far, no additives. I was thinking of adding some dry gas same time as I put the fuel/water separator in...is that a good idea? Thanks again.
     
  6. TerryKing
    Joined: Feb 2007
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    Location: Topsham, Vermont

    TerryKing On The Water SOON

    Guaranteed Fuel??

    Well, I start each season with the fuel pump pulling on a short fuel line to a 1-gallon gasoline can with fresh gas. I can see everything. You might just do that trick, very carefully, with a small separate fuel source well secured.. Then you'll know.
     
  7. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    I had this problem

    ====================================
    I ended up taking tank out, had junk and water on bottom. Try running directly to a spare tank you hook up with new gas fresh gas. Use only a boat tank, and be safe about it. But I almost guarantee its water or other junk in gas. May be stuff filters also. Check filter in tank pickup. good luck go step by step
     
  8. wmoss
    Joined: Jul 2007
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    Location: Pittsburgh, PA, US

    wmoss Junior Member

    Thank you mydauphin. Picked up fuel/water separator and an above deck tank for testing. I appreciate the knowldege from everyone. Looks like I have the weekend to work this out. No Internet access at the lake (good thing), so I'll post next week with my results. Thanks again to all.
     
  9. wmoss
    Joined: Jul 2007
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    Location: Pittsburgh, PA, US

    wmoss Junior Member

    Update: I installed a fuel/water seperator, added some dry gas and the boat seemed to run fine. I let it idle for 5-10 mins (longer than it's run in quite some time) then shut it down. Went out the next day to take her on the lake and she started doing the same stall-restart-stall after a couple of minutes.

    Do you think there is so much water in the tank that the filter I put in is saturated? I could only find the type that looks like an oil filter, not the see thru draininable tye. I was looking at the tank and it seems to be quite a job to remove it. It's in a 1995 18' Rinker open bow. Looks like the entire deck and furniture have to come out to get to the tank. I'm thinking of pumping it out first...any ideas?

    Thanks as always to all for the help.
     
  10. Frosty

    Frosty Previous Member

    We have to get something straight here. You say it stalls abruptly, This is the clue. How abrupt? If it is fuel it will stumble and cough for quite a few seconds if it were running out of fuel, so the fuel bowl is empty ,--so how can it start right up again?

    Its a loose wire some where, check all wires to coil and dist etc. Remove and squeeze slightly with pliers.

    You could rig up a simple bulb connected to the coil, if it stalls and the light never flickered then its not ign
     
  11. jhahn
    Joined: Aug 2007
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    Location: cedar rapids

    jhahn Junior Member

    Did you figure this out yet? It could be your coil. I had a truck that acted like that. Run fine until warm , better on cold days, then die like someone cut the fuel line. Wait 5 mins then start and run 3 min or so. Let it cool down completely, same thing. After doing all the fuel related fixes, someone told me to replace the coil. Problem solved.
     
  12. wmoss
    Joined: Jul 2007
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    Location: Pittsburgh, PA, US

    wmoss Junior Member

    Well, no I didn't. I gave up and took it to the Marina. I told the mechanic about the symptoms & my troubleshooting and he seemed stumped (I saw $$$ signs in his eyes too). He was going to look to the carb first. He thought there might be dirt trapped under the float and that it floods the engine. He was going to rebuild the carb first.

    Hopefully I'll have good news soon. I appreciate the help and support of all.
     
  13. wmoss
    Joined: Jul 2007
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    Location: Pittsburgh, PA, US

    wmoss Junior Member

    Update

    Well, the marina finally called to say they solved the problem. Mechanic told me it was the ignition and the wiring from it? Said they had fallen apart and that caused a loss of spark at intermitent times. Guess I should have narrowed the problem down better by following the advice here, but I am still not sure I could have solved this one. But, for the $ 419.00 bill I could have spent some more time on it. Thanks to all for the advice.
     
  14. RickVT
    Joined: Sep 2022
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    Location: Sanbornville NH

    RickVT New Member

    So I found this thread and it applies to my 1996 3.0 mercruiser that has the exact same issue in that my boat stalls out after a little bit and when I let it sit for a few minutes it will start again and repeats. So I replaced the fuel filter separator, fuel pump, carburetor and the thermostat. I just ordered the distributor and wires and I will reply to this if that fixes the issue.
     

  15. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Dated thread. One way to check for electrical problems is to run at nite. Engine fireworks are bad.
     
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