Carb rebuilt on SBC because the car had been sitting for a couple years with very minor use. Now having problem with car starting after sitting overnight. Spray a little ether and it'll start and run. Shut off and restart after warm or drive and restart, and no issues. Accelerator pump?
Before you start it when it's cold take the air cleaner off look down the carb and pump it once or twice and see if the accelerator pump squirts gas down the carb
Put a phenolic spacer under it. Edelbrock carbs are known for heat soak and the gas evaporates. If you're using a mechanical fuel pump [and in good condition] consider a low pressure [flow-thru] electric pump as a primer pump. Connect this inline before the mechanical pump. This ^^^^ is a modern gas.....Carburetor problem One last thing before you start spending............remove the fuel cap overnight to see if the tank is breathing properly and not siphoning back in the fuel lines.
Them old E Brock’s are kinda bad starting after sitting , if the pump is workin, then the fuel has evaporated , so the bowls need to be filled . I just have to live with mine !!!
Does it bog down when you mash the gas pedal? If not ......the accelerator pump is OK A failing fuel pump will syphon back [the check valves leak] and there could also be a blocked screen in the fuel pick-up. Modern fuels [especially winter blends] have a high butane percentage. This will vaporise with engine bay heat after the engine is shut down.[emptying the float bowl] Most carbs feed the accelerator pump from the bottom of the float bowl, and the jets further up [hence float levels] So a couple of pumps can sometimes get the engine to fire, BUT it won't run [you can do this until the battery eventually goes flat] This isn't a problem on modern EFI engines The fix is AVGAS or an electric fuel pump [or a cap full of paint thinners down the carb]