Yanmar 4JH2-TE cold start

lyleh

.
Jan 3, 2016
9
Hunter 42 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.
 
May 25, 2012
4,333
john alden caravelle 42 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
 
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Likes: TomY
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored 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.
 
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Likes: jon hansen
May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
note: 100% of my fuel line on aeolus is brass. no rubber- style lines involved.
 
Last edited:

lyleh

.
Jan 3, 2016
9
Hunter 42 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.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored 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.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored 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.
 
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Likes: jon hansen

lyleh

.
Jan 3, 2016
9
Hunter 42 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.
 
Dec 25, 2000
5,704
Hunter Passage 42 Shelter Bay, WA
You guys are good.
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.
 

lyleh

.
Jan 3, 2016
9
Hunter 42 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.
 
Dec 25, 2000
5,704
Hunter Passage 42 Shelter Bay, WA
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.
Agree. We stayed two days. Very nice staff, wonderfully accommodating.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored 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.
 
Dec 25, 2000
5,704
Hunter Passage 42 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.