1999 Chevy Blazer Fuel Pump

I have had this Blazer for several months and no shop can tell me what's wrong ! Everyone says have the fuel pump checked ! Only way this Blazer will start after sitting a couple hours is to spray starter fluid in the throttle body and once it cranks it runs like a brand new car never misses or cuts out ! It has fuel pressure through the lines and fuel filter is not stopped up ! We have been cranking it for 2 months this way and afraid of hurting the motor ! Please help ! ! !