The fuel pressure gauge on my supercharged z06 acting funny. My fuel pressure always stays at 60psi. The other day as I was driving I seen come all the way to zero for about 1minute and slowly went back up to about 40psi. After the car sitting for about an hour I fired it up and it was back at 60psi. After driving for about 30min I seen come down to 50psi. It's been fluctuating from about 45psi to about 50psi. But every time the car sits and I fire it up it goes back to normal and slowly drop to 50psi or a little lower. The only thing I did different was put a Lucas fuel system cleaner in my gas tank before I filled up which I never done before. Any help would be appreciated.