Narrative:

In cruise flight; about to start descent; when the engine quit. [I] declared emergency while switching fuel tanks; electric pump on; and mixture rich. Checked fuel gauges and tank being used showed half. After about 15 to 20 seconds [the] engine came back [on] and seemed fine. Canceled emergency and continued on without incident. When plane was checked [a] problem with [a] stuck fuel sender [was] found.

Google
 

Original NASA ASRS Text

Title: A PA-24 pilot declared an emergency when the engine failed as he reduced power for descent. When the engine restarted he continued to his airport of intended landing where he learned a 'fuel sender' had stuck; starving the engine for fuel until it recovered.

Narrative: In cruise flight; about to start descent; when the engine quit. [I] declared emergency while switching fuel tanks; electric pump on; and mixture rich. Checked fuel gauges and tank being used showed half. After about 15 to 20 seconds [the] engine came back [on] and seemed fine. Canceled emergency and continued on without incident. When plane was checked [a] problem with [a] stuck fuel sender [was] found.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.