Starting inconsistently There is no fuel smell

My vehicle has started not starting consistently. There is no fuel smell. The fuel pump sounds when ignition is turned on, and provides pressure to the place where a gauge would be connected (screw driver at this point will cause fuel to squirt).
The strange symptom is that if starter fluid is sprayed in the intake when the engine is cranked, the car will start and works for a day or more. If the car is warmed up well (driven on the freeway) and left to sit for hours it seems the problem reoccurs more often.
I have just over 80,000 miles on the car. The fuel filter was changed by the dealer a year ago.