I have a 1977 F-250 with a 460. I have rebuilt the carb and I can get it to run great but after it runs for a while it will stop delivering gas and I can check the bowl in the carb and it will be empty.
For example today I picked up my new float for the carb to I opened it up and installed the new float. I adjusted it as necessary and I replaced the cover, installed carb to engine and tried to start the truck. After cracking for a long time (while giving the starter breaks) I got gas to fill the carb again. I just couldn't get it to start. I dumped a small amout of gas into the carb while cranking the engine and then it would start and then would die. After three or four times of this it was running. I allowed it to idle in the drive for about 20 minutes. It was full operating temprature (thermostat open). Then I drove it about a half mile down the street at 40 mph stopped and turned around and came back. When I got back to the drive way it seemed to be stuck on fast idle, I pulled the air cleaner and the fast idle cam was not engaged but it was still running fast. I turned it off and then started it again just fine but still fast idle. After about a minute is quit again check the bowl ... and there is no gas again.
Does anybody have any good ideas?
Is the fuel pump weak?
Is the carb put together wrong?
This is my first carb rebuild.

I don't know the carb number for this carb but all the adjustments seem to have the same number for 77 460 in a truck. Please help I am lost. This has been a week long carb rebuild and I am just tired of it... I just want to get it working again.

 

The fast idle you discribed sounds like a lean condition caused by fuel starvation. Just before the engine dies when at idle it will lean out and rev up. Did you have this problem before you rebuilt the carb?

Check the usual suspects. Fuel filter. Fuel pump. Fuel lines may be kinked or have a hole. A loose hose clamp between the tank and the pump could allow air to get sucked into the fuel line. A clogged fuel pick up in the tank. Start at the carb. and work your way back.

Check the weep hole on the pump for any sign of gas coming out of it. If there is the pump is shot. Good luck.

 

I have found to problem!! My main tank was empty and I have been using the Auxilary tank since I bought it two weeks ago. I had a bad ground on my switching valve and it was causing the switch to default back to the main tank (which is empty) and thus the carb was running out of gas in the bowl.

No gas in the tank = no fuel in the carb!!

Of course I learned this after opening the carb 8 times (Free but alot of hours) replacing the float ($10) blowing out the lines (free) replacing a fuel pump ($17) and a whole lot of head scratching and being frustrated. Now I can go on with my life, play with my kids more and sell that Windstar!

 

Glad you got it fixed