When the car is cold it starts and runs fine. RPM at 7k. As it warms the RPM drops to 5k and stalls at stops. Not sure where to start.

 

More information is needed.

Number of kilometres/miles on the vehicle?

What is the available battery voltage across the terminals with the ignition OFF when checked with a voltmeter?

What DTCs are stored?

 

Start with a new fuel pump. It probably hasn't been replaced because it's a very difficult job and it might be 30 years old.

Then check the gap on the crank position sensor. It's also something that should be replaced at this point.

 

Something is happening when the car gets warmed up and goes into closed loop.

Obviously you should invest $20 in an OBD2 reader to pull any codes the car is showing. Without that you are working in the blind.

I would first make absolutely sure you have no vacuum leaks between the throttle body, MAF and engine cam cover.

After that, I would ask you when was the last time the oxygen sensors were replaced.

After that, I might replace the crank position sensor, it’s an easy $20 part that can cause this problem.