Boxster Base Hard Starting

[M. Murphy]

98 Boxster Base >225k miles, a couple of days ago after two days in the garage attempted to start. At first it started normally, ran fine for a few seconds then died, cranked and sputtered during cranking several times until I cranked with a slightly open throttle. Started, cleared up and ran fine. Ambient temp about 55 degrees with moderately high humidity, the garage was dry and no condensation on the car. I'm thinking possibly a sensor susceptible to humidity, any ideas?

Thanks