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Yanmar 4JH2-TE cold start

Discussion in 'Big Boats' started by lyleh, Mar 6, 2018. Add this thread to a FAQ

  1. lyleh

    lyleh

    Joined Jan 3, 2016
    6 posts, 0 likes
    Hunter 42
    Ca North Saanich
    I have a 2004 Hunter P42 with the Yanmar 4JH2-TE engine. This engine does not have preheat but has always been easy to start when cold with very little cranking and throttle at idle. Lately it has been hard to start when cold requiring 10 seconds plus of continuous cranking with a wide open throttle until it catches. Any idea what would cause the change? Engine has 1800 hours on it.
     


  2. jon hansen

    jon hansen

    Joined May 25, 2012
    810 posts, 345 likes
    john alden caravelle 42
    us sturgeon bay, wis
    minut amount of air in the line is a possibility. not enough to have you bleed the system but some. checking the tightness of the fuel line connections is a place to start. on my 66' perkins i had same. had to replace dried out mini gaskets in the fuel line
     


    TomY likes this.
  3. jssailem

    jssailem

    Joined Oct 22, 2014
    5,217 posts, 1,662 likes
    CAL 35 Cruiser
    US Salem, Moored Port Everett WA
    @lyleh I think Jon is onto a possible cause. Diesels want clean fuel, Air and compression to run. Weaken one of those and starting issues.
    When it starts do you see smoke out the exhaust. An oil or diesel sheen on the water?
    Diesel when compressed will ignight and your engine begins to fire off. If there is too much air you do not get the bang. Too much fuel the same result. By running the starter the compression builds and bang it starts for you.
    1. I would look to the fuel first. Clean the filters (they can slow the amount of fuel the engine gets when clogged).
    2. Check the fuel lines from the tank to the antomizers (injectors) for any leak. Remember the fuel line is sucking. So sometimes no leak is found but air can seep in. Check the filter to be sure no air is in the filter. On one engine I saw bubbles in the filter while the engine was running. The fuel line vacuum gauge read 0. Tightened the hose clamp and bubbles disappeared.
    3. If you have an air filter, check for cleanliness. Check the air intake to be sure no debris has found it’s way into the pipes.
    4. Then if still not solved get a compression check.
    Best of luck mate.
     


    jon hansen likes this.
  4. jon hansen

    jon hansen

    Joined May 25, 2012
    810 posts, 345 likes
    john alden caravelle 42
    us sturgeon bay, wis
    note: 100% of my fuel line on aeolus is brass. no rubber- style lines involved.
     


    Last edited: Mar 6, 2018
  5. lyleh

    lyleh

    Joined Jan 3, 2016
    6 posts, 0 likes
    Hunter 42
    Ca North Saanich
    Thanks for the replys. I will change the fuel
    Filter and check all the lines for leaks. It does smoke a little until it warms up but it always has. There is a small diesel sheen in the water after start.
     


  6. jssailem

    jssailem

    Joined Oct 22, 2014
    5,217 posts, 1,662 likes
    CAL 35 Cruiser
    US Salem, Moored Port Everett WA
    Same here Jon on the engine. It is a Perkins thing. I do have clamped hoses from the tank to the primary filter and then to the engine filter.
     


  7. jssailem

    jssailem

    Joined Oct 22, 2014
    5,217 posts, 1,662 likes
    CAL 35 Cruiser
    US Salem, Moored Port Everett WA
    I would start with the fuel lines, then the air intake. My guess you are pumping fuel into the cylinders with air in the fuel line. Air does not compress enough so no fire. Eventually the air fuel mix gets correct and you start (10 seconds I believe you said). Hopefully checking and tightening the fuel lines is enough to correct the issue. I have tube fittings as well as hoses. In that case you need copper compression fittings to seal the lines. If they have been released and then tightened again they need to be replaced. They are not intended to be multi reusable and still maintain seal.
     


    jon hansen likes this.
  8. lyleh

    lyleh

    Joined Jan 3, 2016
    6 posts, 0 likes
    Hunter 42
    Ca North Saanich
    You guys are good. I changed the fuel filters and tightened all fuel line connectors. It started up right away when cold. I also realized it has a boost compensator cancel control to help with cold starts. Thanks for the help.
     


  9. Terry Cox

    Terry Cox

    Joined Dec 25, 2000
    3,182 posts, 300 likes
    Hunter Passage 42
    US Shelter Bay, WA
    John is good. By the way, perhaps he has earned a a brewsky or two. A few years ago my son and I visited the North Saanich Yacht Club for a few on tap while we visited the Gardens. We especially like the Race Rock Ale, by Lighthouse Brewery.
     


  10. lyleh

    lyleh

    Joined Jan 3, 2016
    6 posts, 0 likes
    Hunter 42
    Ca North Saanich
    North Saanich Yacht Club is a nice spot and the Race Rock Ale is a good beer. I’m lucky to call it my home port.
     


  11. jssailem

    jssailem

    Joined Oct 22, 2014
    5,217 posts, 1,662 likes
    CAL 35 Cruiser
    US Salem, Moored Port Everett WA
    Did I hear beer?
     


    kloudie1 likes this.
  12. Terry Cox

    Terry Cox

    Joined Dec 25, 2000
    3,182 posts, 300 likes
    Hunter Passage 42
    US Shelter Bay, WA
    Your comment brought back fond memories:

     


  13. Terry Cox

    Terry Cox

    Joined Dec 25, 2000
    3,182 posts, 300 likes
    Hunter Passage 42
    US Shelter Bay, WA
    Agree. We stayed two days. Very nice staff, wonderfully accommodating.
     


  14. jssailem

    jssailem

    Joined Oct 22, 2014
    5,217 posts, 1,662 likes
    CAL 35 Cruiser
    US Salem, Moored Port Everett WA
    I remember that commercial... Loved the ads. Makes me want to out into the out doors and search for them Rainiers... I heard they run in packs.
    Hide by burying they necks in the snow.
    [​IMG]
     


  15. Terry Cox

    Terry Cox

    Joined Dec 25, 2000
    3,182 posts, 300 likes
    Hunter Passage 42
    US Shelter Bay, WA
    Growing up we had two choices of beer in Willapa from our small grocery store down the street, Rainier and Olympia. Always looked for the four dots behind the label on Olympia stubbies.