1992 Chevy Corsica Fuel Pressure system and fuel pump

1992 Chevy Corsica Automatic 135000 miles

Well, I've had my car for about a half a year now and out of the blue it cut off on me a few days ago. It's a 92 chevy corsica. I got it towed to a shop and they say the problem is either the whole fuel pump system or its a sensor. They think it may be the sensor because the psi is 36 and it should be between 41 and 47 psi but they arn't sure which is the problem. Sounds like they are trying to hustle me but it would be very helpful to kind of get a second opinion of what it might be before I make my next move.