Arduino strange behavior

Hi all, im new to this forum but I have some experience with using arduino.

The issue im having is with a project im creating, it involves using 2 untrasonic sensors. Hc-sr04 version 2 to be exact. I have used these sensors in the exact same way before, im now trying to replicate the device.

Issue:

When i plug the sensors into the arduino nano and onto my power supply (which the arduino also runs off of) runs very very slow, I have serial print stages in my code so I can track the behaviour of the system, and it only cycles through the loop every 1 or 2 seconds, whereas when i unplug the sensors from the power supply it runs back at its normal speed ( filling the serial monitor up with lines of code in the blink of an eye)

I have checked all of my wiring to make sure there aren't any shorts or touching soldered joints.

Any help will be appreciated as i need to get this device functional as soon as i can

Thanks,
Arran

Please post the sketch and schematic of your project