86konaz28

Hello, i have a 86 z28 camaro with a holley 650 carb. I have a issue with the car, it randomly will start surging on the road and within a minute will stall. After sitting for 5-10 minutes the car will start and randomly stall again later in my drive. I have replaced motors, fuel regulators (due to swapping from a tpi to the carb setup and using in tank fuel pump) cleaned out the carb internally (which is only 4-5 years old). The only thing i noticed which is why i replaced the regulator (which is a bypass style) is that the pump is fluctuating about 3-4 psi and increases to a bigger fluctuating amount as i increase the pressure. Has anyone had the fuel pump in tank fail this way? (The setup has not changed from before when the car was my daily driver either)