When the engine is cold it holds idle just fine. The engine temp gets to 200 it will not hold idle at a stop. It will start if I flood the carp. What would cause this. It has a Eldbrock carp on it. Could it be the coil ignition heating up?

I don't know about the carp, but it sounds like you might be experiencing vapor lock with the carb. While she's warming up, it holds idle at say 170-180?

Which car is it?
Does sound like a fuel problem, but could also be ignition, or the distributor vacuum.

I would check your idle mixture setting,,vacuum leaks at the throttle bar,,idle setting off choke..is it an electric choke??  Mine gets stuck once in a while-not electirc though--make sure to set the idle with the choke completely off and reset timing,,I just did a full point coil cap and rotor tune up--took a little time but once set up it will run fine..do you have power brakes?? you can lose vacuum in that system also and lean it out.  of course I am assuming that when it shuts off it restarts immediately after and runs fine as long as you apply throttle.

Sorry about getting back so late. In this months Corvette magazine in the tech nerd somebody ask the same question. He thought it might be the carb getting to hot and expanding the fuel. He suggested putting a spacer on the intake manifold. When my car dies the 70 I have to flood the carb for it to start. It does have electronic ignition. Still not sure of the problem?