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Discussion Starter · #1 ·
Today, I was doing some PM on Hush. Changed the racor filter and as luck would have managed to get air in the fuel system. I have a 3hm35f with an electric fuel pump. I turned the ignition on, bled the primary, moved to the fuel pump, popped the bleed there then worked the three outlet lines from the fuel pump. Had clear fuel there. Usually I have been able to stop there, do I have to continue to the injectors and crack them too....I have likely been lucky in the past. Does anyone have any logical step by step procedure they use. Am I just out to lunch on this?

p.s. I forgot about the water intake and may have filled the muffler...will that slowly drain out or will it end up in the engine??? HELP
 

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Today, I was doing some PM on Hush. Changed the racor filter and as luck would have managed to get air in the fuel system. I have a 3hm35f with an electric fuel pump. I turned the ignition on, bled the primary, moved to the fuel pump, popped the bleed there then worked the three outlet lines from the fuel pump. Had clear fuel there. Usually I have been able to stop there, do I have to continue to the injectors and crack them too....I have likely been lucky in the past. Does anyone have any logical step by step procedure they use. Am I just out to lunch on this?

p.s. I forgot about the water intake and may have filled the muffler...will that slowly drain out or will it end up in the engine??? HELP
If you are going to bleed the injectors, I strongly urge you to use flare nut wrenches. If yours are like mine, they are very easy to damage using regular wrenches.
 

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Maine Dub
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I think if you have bled the high pressure fuel pump it will take care of the injectors. If you have been cranking the engine over with the raw water intake open you may have already got water in the engine. Check that out soon.
 

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FWIW - last time I bled my injectors, I had to try three times to get it to work. Even if it does not work at first, it might still be worth trying. As Al points out, for sure make sure you turn off the raw water intake seacock. Also turn the throttle up almost all the way before you start cranking. I found a couple good videos online that walk through the process. The video I watched it took him several tries too.

IIRC, the procedure I used is:

Before you start clean really well around the injectors. You do not want to get a speck of dust in the engine or very bad things will happen I imagine. For the same reason, crack them as little as possible.

1) Close water inlet. Put engine in forward and throttle on max.
2) Crack all the injectors using flare nut wrench
3) Crank engine until you see fuel exiting all three injectors
4) Tighten the injectors (use fairly low torque)
5) Put throttle back to idle and transmission back to neutral
6) Attempt to start engine
7) If engine starts, make sure to open seacock within a minute or so
8) If engine does not start, repeat.
 

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Discussion Starter · #5 ·
Went to the boat today...drained the water muffler in case I had high water. Managed to follow all your advice and fixed the problem. I really appreciate everyones help.

p.s. I think the difference was that I actually used the correct air bleed on the primary filter.
 

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Coastal Carolinas
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One more tip that seems to help. Close the fuel petcock at the tank prior to changing the Racor fuel filter. That will prevent the fuel lines from emptying into fuel tank when you crack the Racor housing. Much easier to bleed after filter replaced and fuel tank petcock valve re-opened again.

John S
PSC 34 #201
Norstar
 

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Raindog,
Great post on the bleed procedures. I have never heard the part about putting the transmission in gear. What is the reason for doing that? Seems like you are just putting more stress on the starter as it tries to turn the prop and transmission gears. Having the engine in gear shouldn't affect the fuel flow if the engine is not running. What am I missing?
 

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Raindog,
Great post on the bleed procedures. I have never heard the part about putting the transmission in gear. What is the reason for doing that? Seems like you are just putting more stress on the starter as it tries to turn the prop and transmission gears. Having the engine in gear shouldn't affect the fuel flow if the engine is not running. What am I missing?
I could be remembering wrong. I was doing that from memory (am not on the boat and my shop manual is). I thought the purpose was to keep the engine from starting.
 

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A properly installed neutral safety switch should prevent most people from trying to bleed their motor while still in gear... so everyone else, don't do it, ok? geesh free advice...
 

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If you give it a little thought... a diesel cant start while you are bleeding the injectors,... because the fuel wont be going into the cylinders, it will be squirting and spraying your motor on the exterior, unable to achieve the 150 BAR + , required to pop the injector in the combustion chamber. Wether you have it in gear or not.
 

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I read the thread and I feel that I miss something.
My Engine is Yanmar 4JH2E. I have a fuel pump "Walbro"
installed after the primary fuel filter. The pump starts when I turn the key to On.
After replacing the fuel filters I turn on the key and I wait for the pump to relax. At the beginning the clicks are intensive and later its click...... click......click. At that stage I understand that there is no air in the system.
Than I start the Engine and it never fails me.
I own the boat almost ten years and never had to bleed the Engine.
 

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The Yanmar JH series engines are "self bleeding". The fuel feed line from the pump and the return fuel line back to the fuel tank both connect to the top of the on-engine fuel filter manifold. When you pressurize the fuel system any air bubbles are pushed out of the system through the return line back into the fuel tank. So in theory air bubbles cannot continue to the high pressure injection pump. As Psc242 stated you only have to run the electric pump for a minute or so to expel the air. I'm not sure it is fool proof though and I usually bleed air at the top of the engine mounted fuel filter because it is easy to do. I've never had to bleed the injectors.
However, not all engines are designed this way and there is no place for the air to escape - hence the requirement to bleed the system prior to starting.
 

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Thank You BMLipiec.
Now I know.
So far for me it is full proof. Never had a problem.
Is that why I can leave my pump working after the engine was turn on?
Pacific Seacraft build the system without a switch to turn off the pump and it works perfectly.
 

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If you give it a little thought... a diesel cant start while you are bleeding the injectors,... because the fuel wont be going into the cylinders, it will be squirting and spraying your motor on the exterior, unable to achieve the 150 BAR + , required to pop the injector in the combustion chamber. Wether you have it in gear or not.
It can start with an injector cracked. It just runs rough.

JD 6330. JD 6110. JD 5085 M. Ford 7.3 PSD x4

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