I have replaced my shallow well jet pump and done all I can think of. Including priming. I turn the pump on and only have 20PSI, and the pump will not turn off because of just getting 20 PSI and not the minimum. What am I doing wrong?

How many pipes go into the well, one or two?

How far down to water?

Why did you need to replace the old pump? Did you also replace the well pipe?