I have a jet pump that I have been working on priming. I have an addition going in and the water lines were disconnected. I can get the pump to prime but I cannot get the pressure over 30 lbs. I shut off the pump and the pressure will hold at 30 but I cannot get it above. Any suggestions?

You may have an obstruction in the jet assembly venturi, it only takes a pea sized piece of sediment to impede the flow through that fitting.
If you have a valve between the pump & the tank, try repriming from 0, and as the pressure rises past 20lbs, close the valve slowly and throttle the flow to see if you can get the pressure to spike past 30lbs & beyond...