Heat cream in a 2 1/2- to 3-quart heavy saucepan over moderate heat until it just reaches a boil, then add hot cream to egg mixture in a slow stream, whisking.
Pour custard into saucepan.
Cook custard over moderately low heat, stirring constantly, until it registers 170°F on an instant-read or candy thermometer (do not let boil).
Pour custard through a fine sieve into a clean bowl and cool completely. Stir in passion-fruit pulp, then chill, covered, until cold.
Freeze custard in ice cream maker.
Transfer to an airtight container and put in freezer to harden.
