Fuel Pump Question

[pogofx]

Sorry for the ignorance, I'm still finding my way around the inboards after being a jet boat owner for 10 years.

Anyways, I'm having trouble starting my boat for the first time this year (310HP Holley Carb). Started off suspecting stale gas, although I did use Stabil Ethanol treatment last time I used it. It'll start for a little bit if I use starting fluid, but will quickly die out. Now I'm starting to suspect the fuel pump. My question is, does the fuel pump run with the ignition on and the kill switch key in? When I have the key turned to the last position (before engaging the starter) and the kill switch key in, I don't hear anything from the fuel pump. Should I? Thanks in advance.

[pogofx]

After pulling out the voltmeter, it seems that the fuel pump gets voltage when the key is turned to the starting position and not in the on position without the engine running. Not sure if that's the correct behavior or not, so I need some help there. Can't really hear if the pump is running while trying to crank. Would the best way to test the fuel pump be to pull it and just hook it up to 12V?

[harmsway]

The electric fuel pump should see 12v during cranking and it will only have 12v in the run position if the oil pressure switch detects that there is oil pressure. Once the oil pressure switch detects there is oil pressure it will send a 12v signal to the electric fuel pump. If you straight wire the pump it should run all the time, that would be a good way to test the fuel pump and eleminate that there is not another problem.

[jmb]

When I turn my key to the on position (before starting it), my fuel pump runs for about a second or two. You should hear it each time you turn the key on from the off position

[pogofx]

Thanks, that pretty much the conclusion that I came up with for the fuel pump voltage. Figured that the pump must keep the voltage in the run position only if the engine was running. Didn't know that it was the oil pressure switch. Good to know, thanks. That's exactly what I'll do tomorrow - jump the pump to the battery momentarily to make sure it runs and then go from there. Even if it runs, I suppose it could still be putting out low pressure, but one step at a time.

[pogofx]

When I turn my key to the on position (before starting it), my fuel pump runs for about a second or two. You should hear it each time you turn the key on from the off position

Would it be any different for a non-EFI like mine? I don't hear the pump at all, even momentarily. I'm pretty sure that I would have heard it when I was disconnecting the leads to the pump and then reconnecting them with the battery switch on. I was right there on it and heard nothing.

[pogofx]

SOLVED! Hot wired the fuel pump and found it was running fine. Disconnected the fuel line going into the carb and got no gas while running the fuel pump. Also disconnected the fuel line going into the fuel pump and found it bone dry. Suspected the fuel filter, but after reading about someone else on here who had a similar problem with the anti-siphon valve coming out of the fuel tank, decide to start there. When I pulled the anti-siphon valve discovered that the line leading out of it to the fuel filter and pump was also dry. Worked the ball bearing valve a couple of times with a screwdriver and reassembled. Primed the fuel line with gas and manually ran the pump again with fuel line disconnected to the the carb and feeding back into the my gas can. Ran it a few seconds and got a good flow of gas. Reconnected everything and she started right up on the first try. Would have never thought of that anti-siphon valve if it wasn't for this board. Thanks! Hopefully this will help someone else out as well.

[harmsway]

With all of my boats in the past that were carburetor engines the marine carburetor had an open tube going into the float bowl that you could pour fuel through to fill the float bowls up with gas (a couple of ounces). After doing this the engine should run for a couple of minutes before going dry. Another thing to remember if you get to the point that you need to test fuel pressure a carburetor engine should have 3 1/2-7 1/2 psi.

[pogofx]

Thanks, good info.