fuel pump

1973 FORD F-250
67,000 MILES • 6.4L • V8 • 2WD • AUTOMATIC
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GFFR57
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Recently rebuilt a 390 motor in a 73 f250. Fuel pump is brand new. Started it up after I installed the motor and it ran great while I made all my timing adjustments, checked for leaks, etc. Two days later, it is not getting any fuel to the carburetor. I changed the filter and still nothing. I disconnected the line from the pump to the carburetor and barely a drop or two is coming out of the pump when it turns over. Is there a filter or screen in the fuel tank that could be plugged? The truck sat for some time before the rebuild so that would make sense. Help!

Update: disconnected the intake side of the fuel pump, connected a temporary line, and put it in a gas can. It would not draw up any fuel or create suction. could the pump be full of debris from the tank or just a defective fuel pump?
Dec 23, 2017 at 1:34 PM
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CJ MEDEVAC
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Along with the gas can trick,

Did you also disconnect a rubber line before the carburetor on the output side of the pump?

The pump will not pump if it is not going somewhere.

Keep us posted.

The Medic
Dec 24, 2017 at 2:19 PM
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GFFR57
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I feel like I have tried everything at this point. I just replaced the fuel pump and still nothing. Is it possible the eccentric on the cam timing sprocket is spinning and not working the lever on the pump?
Dec 25, 2017 at 4:26 PM
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CJ MEDEVAC
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Did you take the fuel line loose near the carburetor and try out the suction line in the gas can as you mentioned before?

Do you get fuel through the pump and out of the open line?

Sort of want to try the easy options first, before you start thinking complicated or the worse.

The Medic
Dec 25, 2017 at 4:35 PM
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GFFR57
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Yes, I disconnected at the carburetor as well. No fuel coming through at all. Siphoned some fuel through the line at the intake side of the pump too and it came right out so it is not plugged at the tank or fuel lines.
Dec 26, 2017 at 3:23 PM
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CJ MEDEVAC
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I reckon your next step would be to investigate the eccentric.

Can you see it (maybe a mirror) with the pump removed?

Might wanna take the fan belts off and turn it over to see the action.

The Medic
Dec 27, 2017 at 6:56 PM
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GFFR57
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I agree. I remember pressing a pin out of the old cam timing sprocket when I replaced it. I don't remember exactly what that pin did. Does it hold the eccentric so it doesn't spin? I remember it not fitting near as tight when I put the pin in the new sprocket. I'm guessing that if that is what that pin does then it may have fell out.
Dec 28, 2017 at 2:36 PM
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STRAILER
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Yep that will do it becasue the pin sets the timing of the camshaft.
Dec 31, 2017 at 1:37 PM
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GFFR57
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ok thanks for the help! I'll dig into that and see if that's it. I'm guessing it is.
Dec 31, 2017 at 6:30 PM
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STRAILER
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Good to hear, please use 2CarPros anytime we are here to help.

Cheers, Ken
Jan 2, 2018 at 10:28 AM