pressure problem

I'm posting this for my neighbor. Hopefully someone can help him out.
He has a 1 1/2 HP deep well jet pump. Never has a problem with well running low.
The problem started out as pump would not shut off. Pump was building extremely high pressure. He had to shut the breaker off to get the pump to shut off. He installed a new pressure switch set at 30/50. Pump worked fine for about 2 weeks then would not shut off. Pressure on the gauge would only go up to just over 40 psi. He adjusted the pressure switch to 20/40. Pump cycles on and off but water pressure is too low for practical use. Pressure does not bleed off with the pump sitting idle. Setting the pressure switch any higher keeps the pump from shutting off.
Could it be a pump problem, impellor etc., clogged foot valve, or the jet in the well?
He would appreciate any help you can give on diagnosing the problem. I'll try to get anymore information that might be needed.
Thanks

Either the nozzle in the jet assembly down the well is plugged, or you have a leak in the suction line.

Could be a hole in the casing, but you said it holds water (I think). Plugged Jets rarely allow more than 30 psi. He could have junk in the Impeller or if it's a two stage Pump, one Impeller could be broken.

bob...

Thanks, I'll relay the info to my neighbor.