1977 F250 4wd, with a 1987 460 engine, edelbrock 4 barrel carb.

If you let it sit overnight, it is very hard to start... has to crank for a minute or more to get fuel back to the carb. If you pour fuel in the top of the carb, it'll fire right up. This is in warm weather. In cold weather, pouring gas into the carb was the only way at all to make it start at all. I have two other old V8 engines (1956 Chevy and 1981 Chevy) and both of them start right away overnight -- only act like this if it's been 4 months since I've started them, and even then, they're not that bad.

Once it starts, it runs pretty good, except that it does love vaporlocking if you let it idle in the heat.

What I've done:
Replaced accelerator pump.
Replaced a cracked gas hose on the inlet to the fuel pump, that was sucking in air. The fuel pump feels like it's pumping by hand, but I haven't replaced it yet... that's the next step (now that I know what engine's in there... NOT the '77 400 it came with).
Put an electric fuel pump in line with the mechanical one... though, I may have burned it out when it was sucking air in -- haven't verified that it's working still.

Ideas? Does it sound like a bad fuel pump? Or something in the carb?

 

Sounds like for what ever reason the fuel bowl in the carb is draining out

 

Have you verified that the accelerator pump is working, remove the air breather, look down into the carb and move the linkage, if you see fuel squriting its ok.

 

When mine did that, I just put a band-aid on by putting an electric fuel pump in line to prime it. I havnt done anything else to it but it seemed to snap out of it.

 

X2

This seems to be related to a "design flaw" in the Eddy carbs, the accelerator pump draws fuel from the top of the float bowl instead of from the bottom like a Holley.

With modern gasoline blends the fuel evaporates off quicker than it did in the 60's and 70's, the Eddy carbs run well otherwise.

You would think Edelbrock would have a solution to this after all these years besides using an electric fuel pump.

 

A thick 1/2"+ insulating carb gasket may help reduce boiling of the fuel out of the carb. Worth a try.

 

I'd go with what blue and white said, but check the float levels in the carb, also I would bypass the mechanical pump and put a new filter in the line if the electrical one is still working and see how that does. If its not, remove it and try just a filter then change the mech pump if the problems persists.