Vapor Lock Issue?

I've been having fuel pressure issues on my 1983 Mercury Capri RS. I noticed the fuel pressure gets lower the longer the engine runs or possibly the hotter it gets. I replaced a section of hose with clear vinyl tubing to see if I would get any bubbles. I had the car idle for about 20 minutes before I started recording. The air temp was around 80 degrees Fahrenheit. The fuel pressure dropped steadily from 7 psi to about 1 psi over those 20 minutes. It only started bubbling right before I started to record. Is this what vapor lock looks like?