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Thread: New Yanmar, hard to start, or just cold natured? Reply to Thread
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  Topic Review (Newest First)
11-24-2009 08:39 AM
CanDrac I had the same problem at first. I was doing what the dealer showed me: Glow plugs, rev it up a little, then start. Yet it always stopped after a few seconds...

Then I learned that in warm weather YOU SHOULDN'T HAVE TO DO ANYTHING AT ALL. Now I just turn the key and it starts. Every time!
10-04-2009 03:25 PM
Dockdozer Finally. I want to thank everyone for your help. The first thing I did when I got to the boat was bleed the fuel system. Lot of air! So I went over every fitting from the fuel tank to the engine. One or two seemed lose to me. Pulled the filters checked the gaskets. Bleed the system again and low and behold. Finally she starts like a diesel should. Next morning, touch the key, no glow plugs, less than a second fires right up. YYAAHHOO!!! Let set threw the day same thing. Next morning Same thing!!!!
Thank You All for all your help!!!!!!!
09-29-2009 07:33 PM
SteveInMD With all due respect for my fellow members here...

Looking for a leak...if you have a leak before the lift pump it will be hard to find since it will always be under suction. You just have to go connection by connection and do your best. You could temporarily change our the fuel line leading into the lift pump with clear tubing provided you can find some with thick enough walls so it doesn't collapse. The clear line would show you if you have an air leak before the lift pump. You should see no bubbles with the motor running.

If the leak is between the lift pump and the high pressure pump you should be able to see wetness or dripping fuel.

If the leak were after the high pressure pump you would be running on less than all cylinders, and running rough so I don't think that's the case.

With the hours on the motor you have it's very unlikely to be a bad injector. You can remove them and send them off to be rebuilt, but I think you are barking up the wrong tree.

If you injector pump is so bad that it's leaking back I doubt your motor would run at all. Normally injector pumps do not leak back what so ever. It's also very unlikely the problem at the low hours you have.

You should be able to crack the bleed screw a little on top the secondary filter with the motor running and fuel should squirt out. If not you may have a weak lift pump. Again, this is unlikely since it's a new motor.

If you don't have the Yanmar Parts Manual and Service Manual you should buy them.

You might find taking a class useful. I've worked around diesels for many years, but I learned a lot by taking a level 1 and 2 class on marine diesels. I learned a ton and have put what I learned to good use on my boat.
09-29-2009 06:46 PM
Dockdozer I will have to check the starter and connections, the battery was replaced last year with the engine. I am looking for some gauges so I can look for an air leak. Ok a leaking injector? Are you saying a leak at the fuel line going to the injector, or the injector it self? And that is a new idea that the injector pump leaking back down the return line! Thanks Guys for all the ideas were to look.
09-29-2009 12:36 PM
SteveInMD The Racor should have a 10 or 30 micron element, not 2 micron. You should change that out at some point but I don't think that's the problem right now. If it were you'd have low power.

Slow cranking is a good thought. Are the starter connections and ground wire connections clean and tight? What does the voltage read at the starter during cranking?
09-29-2009 10:46 AM
Originally Posted by Dockdozer View Post
And buy the way I forgot.
Once the engine is started she is fine. Idle is fine and smooth. Will run up to 32000 rpms. Never have herd a sputter. It is just hard to START!
Is your starter motor turning it fast enough? I once went round and round with an engine and realized the problem when I heard an identical engine turn over. I never realized that mine was being turned too slowly. New starter fixed everything, but I can see where you may have a good starter, good battery, and still turn too slowly because of connection problems.

BTW: For cold weather starting I lift the compression release, open the throttle, and give her a 3 second spin. Then I close the compression release, and spin her again. Starts right up.
09-29-2009 10:22 AM
Originally Posted by Dockdozer View Post
And buy the way I forgot.
Once the engine is started she is fine. Idle is fine and smooth. Will run up to 32000 rpms. Never have herd a sputter. It is just hard to START!
Hmmm... I still say the issue is fuel pressure, but I'm not there working on it. Diesel fuel systems do work on very low pressure and once drained can take a while to charge back up. Most diesels will not start after a filter change without a lot of ether, which can do serious harm to your pistons and rod bearings, or manually pressurizing the fuel system. Sounds now like a possible leaking injector causing your pressure to drain while shut down. The return line from the pump to the tank could also be leaking down. There should be an spring-loaded type pressure valve in the pump. The only way to confirm most of this is with lots of gauges, pressurizing the fuel system using an alternative method, and watching where the pressure drops (if any) are taking place. It may be time for a pro with all the right tools to have a go at it. Best of luck.
09-29-2009 08:29 AM
Dockdozer And buy the way I forgot.
Once the engine is started she is fine. Idle is fine and smooth. Will run up to 32000 rpms. Never have herd a sputter. It is just hard to START!
09-29-2009 08:23 AM
Dockdozer Every thing on the engine was replaced new, from fuel lines from the tank to muffler at stern.
I have replaced all filters. And polished the fuel with a pump and filter system at over 2 gal. a min. for over an hour, 40 gal tank. Found very small amount of trash in the fuel. I have since added a fungicide, and the PO used marvel mystery oil, the diesel is a red tent. I have only added 12 gal. of fuel so far and I bring it from home with a 6 gal tanks. Racor 500, 2 micron no trash in bowl as of now. I have found what I believe to be a in line fuel pump at the engine. Then their is a filter on the engine, and I have no clue what micron it may be. Filters are Yanmar and Racor.
I am with you on the air leak but how do I find it????
And Dieselboy I will give you a call!!
09-28-2009 08:09 PM
SteveInMD If your filters are restricting fuel flow you will have low power when you open up the throttle.

If you do replace the filters you should have a 30 or 10 micro primary and a Yanmar secondary. My Yanmar secondary is 2 micron.
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