pressure switch question

I have a customer who just replaced a pressure switch on a shallow well jet pump. The old switch was turning on/off during the cycle. He replaced it with a new switch and it worked fine for about a week. Now the new one will turn on/off real quick when it first turns the pump on then work fine until the cycle is complete. We have checked the tank pressure and it is fine.(2 lbs below the turn-on of the switch).

Any ideas on what is making the switch do this?

Could moving the switch down to the tank instead of directly on the pump help?

Thanks,
Matt

Moving the switch to the tank will certainly help. However, you may just be to close with that air pressure. Try letting out a little air to say 5 PSI below the on pressure.