We have changed regualtors and pressure valves and it keeps going to80 psi can't figure out what to do

Sounds like your PRV (pressure reducing valve) has gone bad. Have it checked and replaced if necessary.
The average house PSI is 45 but it can range betweer 40 and 60 PSI. Good luck, Tom

We did that yesterday, we still are getting unexplained jumps in psi... last night when we went to bed everything was fine when we woke up it was back to 90.

Have you called the Water Department and asked why the street pressure's fluctuating? What did they tell you? Back to you, Tom

I am confused because a new pressure regulator would solve the city's fluctuating pressure issue. You say your replaced the PRV yesterday, right? How did you go about setting the pressure, did you loosen or tighten the screw on the top? Tom's post #2 should have taken care of this