One possible cause could be a failing fuel pump. This is used to provide the fuel pressure and if it fails, then the car might not start or will die out during acceleration. Check to confirm the fuel pump and contact a mechanic for more inquiries.
Can be Catalina converter in the exhaust. I had a 83coupe De Villethat when the converter was shot it had died an after that it had no power and I had to floor it to climb hills. Eventually I put a new exhaust and it ran fine.