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Discussion Starter #1
My NAPA electric fuel pump is making a noise when the ignition key is turned on. Noise is kind of clicking. It only happens when engine is started for the first time. Is that normal? I will buy a new pump just in case but I don’t want to put it on if I don’t have to. Any steps I need to take to make sure I don’t get air into my fuel injection pump? Your help is greatly appreciated.
 

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Clicking is the internal solenoid bringing the pressure up to normal. Normal. If you delay starting the engine and clicking persists ,the pump may be leaking back or there is a leak somewhere (Good fuel to pump so it's not sucking on a limited supply?) If you do open a line to replace or? the worst may be you may have to bleed the engine .Everyone should know how to do that anyway
 

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Discussion Starter #3
Thanks, Len. I hope that’s what it is. Any idea what pressure is that pump producing? The engine is Yanmar 3HM35F. I could not find that parameter in my engine manual. I want to buy a right pump and they go by pressure requirements.
 

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The 3 cyl yanmar in our generator has an electric fuel pump that automatically primes the fuel system, when you hit the start button. It buzzes, more than clicks.

You said NAPA. Is that some sort of aftermarket thing?
 
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Yep, normal. Our Onan also clicks until the fuel is up to pressure and we often hear it when running the glow plug before starting.
 
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Discussion Starter #7
Yes, its a NAPA pump that PO installed between the Racor filter and the injection pump. Any idea what fuel delivery pressure is needed there? I would like to have a backup and guy at NAPA tells me I need to know that. I have read somewhere that it’s about 6 to 8 psi.
 

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Discussion Starter #9
Not much info on that pump that can be seen without uninstalling it.
 

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Yes, its a NAPA pump that PO installed between the Racor filter and the injection pump. Any idea what fuel delivery pressure is needed there? I would like to have a backup and guy at NAPA tells me I need to know that. I have read somewhere that it’s about 6 to 8 psi.
It's not about pressure at that point in the system, just GPH. Obviously, your pump must pump enough fuel for the diesel to run.
We on sailboats don't have much problem with even the smallest pumps rated by GPH but imagine a motor vessel using 75 to over 100 GPH per engine. That's when electric fuel pumps start getting expensive.
 
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For a replacement pump, spend some quality time on the Walbro fuel pump web site. https://www.walbro.com They make USCG approved marine fuel pumps and are the standard Many people sell them.

Bill
If I was running a gas engine, I'd certainly agree with you, but on our small diesels where ignition protection is unnecessary, the cheap ones seem to do just fine.
 
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Automotive technician here; I recommend my customers avoid NAPA parts if at all possible. If it fails in a car, no big deal. Boats are not cars.

Also, a failed diesel lift pump can cause the injection pump to fail.
 

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Typically a Yanmar has a fuel bypass that sends excess fuel that the engine doesn’t need to run, back to the tank. Well, at least the 4-cyl ones do, no reason to think the smaller ones are different.

So if the engine switch is on and the engine isn’t started, the pump you describe will continue clicking interminably as the fuel cycles back to the tank. These pumps click each time they deliver fuel, yours may click more frequently while the engine runs as a result of the through flow system.

I installed a diesel flow pump normally fitted to a Ford Explorer, pumps adequate volume for a 4JH4E and gently buzzes in the background. The downside is that the fuel is warmed by the through-flow and brings the temperature of the whole fuel tank up. I haven’t had problems yet but I often wonder about condensation, diesel bug and all those other horror stories.
 

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Typically a Yanmar has a fuel bypass that sends excess fuel that the engine doesn’t need to run, back to the tank. Well, at least the 4-cyl ones do, no reason to think the smaller ones are different.

So if the engine switch is on and the engine isn’t started, the pump you describe will continue clicking interminably as the fuel cycles back to the tank. These pumps click each time they deliver fuel, yours may click more frequently while the engine runs as a result of the through flow system.

I installed a diesel flow pump normally fitted to a Ford Explorer, pumps adequate volume for a 4JH4E and gently buzzes in the background. The downside is that the fuel is warmed by the through-flow and brings the temperature of the whole fuel tank up. I haven’t had problems yet but I often wonder about condensation, diesel bug and all those other horror stories.
the Yanmar does have a return line on the 4 cylinder and smaller engines but it is from the high pressure injectors and not the lift pump side of the injection pump so it only returns fuel when the engine is running. the reason the engineers have the fuel return back to the fuel tank is to cool the excess fuel that is coming back from the hotter fuel injectors. most Yammers have a mechanical engine driven lift pump and really don't need an electric lift pump unless the tank is placed to low in the system to meet the Yanmar requirements.
 

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A thought... GMC's with unit injectors pump an immense amount of fuel back to the tank to cool their injectors,Little engines do the same but more discreetly. If your system has a short closed loop to save running a return line back to tank any heat or bubbles or crud stays in the loop
 

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Automotive technician here; I recommend my customers avoid NAPA parts if at all possible. If it fails in a car, no big deal. Boats are not cars.

Also, a failed diesel lift pump can cause the injection pump to fail.
lol Well you see, that's the difference between us marine engineers and you Automotive technicians. Whereas you've got to go buy a replacement, we've got one or two spares stuck away in a drawer somewhere and can make the change before you've got your order into NAPA guy.
Two completely different mentalities; sadly, we don't have a NAPA store out there on the briny. lol
 

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Discussion Starter #20
Just bought a replacement pump to have as a spare. It’s a Facet pump. About $85 at NAPA.
Thank you all for your help. As always, very useful. Best sailing forum I know.
 
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