Idle Problem (Wont stay running)
 

I have a new Rochester Dual 210 carb on my 229 engine in my 1980 camaro. The car hasnt been run for 5 years. Got everything ready for a first start up today and gave it a try. The engine started and reved up high to 2500 rpm and stayed there for about 7 seconds then dropped to nothing over the next 3 seconds or so. I am wondering why it wants to idle so high at start up and then wont stay running. Is this a fuel pump problem? I was thinking maybe the diaphram is cracked in the fuel pump. Or could it be a simple idle adjustment? But that still leaves the problem of it dieing within ten seconds or so. I can keep it running if i keep my foot on the gas pumping it and watching the rpms. Please Help!

Fast idle adjustment may be set too high.
Since not ran for five years, I'm sure you have siphoned out all the gas from the tank, added clean fresh gas, then with a rag and shop air, and the pump inlet hose disconnected, slowly pressurized the tank at the filler neck, thus the rag to seal the tube and air gun, as this process primes the fuel line all the way up to the fuel pump.
Then, fill the carb bowl with about 1/3-1/2 cup of fuel poured into the bowl vent, the 1/4 inch diameter tube. This amount of fuel will run the engine and let the mech fule pump start working and supply fuel to the carb.

As a troubleshooting aid, you can fit in the carb inlet line, a clear view fuel filter to see if the fule pump is pumping fuel. The pump should keep the filter full of fuel.
Install the filter with fuel hose in the vertical section of the pump preventing an air bubble.