76 GMC 2500 Fuel Problem

2012 GMC
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BDC961
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I have an old 76 GMC that will run but only when fuel is poured directly into the carburator. I have replaced the fuel pump. I have blown out the fuel lines from the tank selector valve going to the carb and fuel pump. I just don't know what else to do. There is plenty of gas in both tanks. Fuel is just not getting from either tanks to the carb. Could the fuel lines from the tank to the selector valve be cloged. The truck ran before without having to pour gas into the carb.

Any help is appreciated.
Nov 4, 2007 at 8:42 PM
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RASMATAZ
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Check the fuel pump pressure might not be pumping fuel for a starter.

Pressurize it and have someone listen to the tanks.
Nov 4, 2007 at 10:32 PM
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BDC961
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What do I use to pressureize and which line on the pump. What am I listening for at the tanks?

Thanks
Nov 5, 2007 at 1:43 PM
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RASMATAZ
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I have blown out the fuel lines from the tank selector valve going to the carb and fuel pump.

What did you use here? you will hear gushing noise when air is passing thru the lines-if you do it means the lines are clear.

Have you check the fuel pump pressure? If so with the correct pressure, you have a problem with the carb.
Nov 5, 2007 at 2:10 PM