DA40 pilot experiences a rough running engine at 7;500 ft; switches fuel selector from the right tan...

Narrative:

While flying VFR at 7;500 ft AGL while utilizing flight following; I declared an emergency because my engine sputtered. I immediately changed from right fuel tank to left tank. After ATC advised the nearest airport was 10 miles away; I landed safely and the engine never stopped until I turned the engine off. I visually checked that the fuel was very low. Refueled and topped off both tanks; started the plane; performed preflight inspection. The fuel gauge indicated that both tanks were full as I had visually observed. I took off and circled the field 2 or 3 times to be sure that I had experienced faulty gauge or loose ground wire. While refueling; I spoke by phone to my mechanic who assured me that what I had experienced was a faulty gauge or loose ground wire and the plane should operate correctly to continue. After departing; I flew the aircraft on a 10 minute flight; landed and rechecked the fuel in both tanks. While on the ground I performed pre-flight check and all systems seemed good. Flew to destination without incident and did observe normal decrease of fuel from left tank. No recurrences in route and landed safely. A few days later; an a&P mechanic inspected the aircraft; de-fueled both tanks and determined that the plane had a faulty fuel sensor. Parts were ordered. The plane will be repaired in a few days.

Original NASA ASRS Text

Title: DA40 pilot experiences a rough running engine at 7;500 FT; switches fuel selector from the right tank to the left; and diverts to the nearest airport. Low fuel and an inaccurate fuel gauge is determined to be the cause.

Narrative: While flying VFR at 7;500 FT AGL while utilizing flight following; I declared an emergency because my engine sputtered. I immediately changed from right fuel tank to left tank. After ATC advised the nearest airport was 10 miles away; I landed safely and the engine never stopped until I turned the engine off. I visually checked that the fuel was very low. Refueled and topped off both tanks; started the plane; performed preflight inspection. The fuel gauge indicated that both tanks were full as I had visually observed. I took off and circled the field 2 or 3 times to be sure that I had experienced faulty gauge or loose ground wire. While refueling; I spoke by phone to my Mechanic who assured me that what I had experienced was a faulty gauge or loose ground wire and the plane should operate correctly to continue. After departing; I flew the aircraft on a 10 minute flight; landed and rechecked the fuel in both tanks. While on the ground I performed pre-flight check and all systems seemed good. Flew to destination without incident and did observe normal decrease of fuel from left tank. No recurrences in route and landed safely. A few days later; an A&P Mechanic inspected the aircraft; de-fueled both tanks and determined that the plane had a faulty fuel sensor. Parts were ordered. The plane will be repaired in a few days.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1056854
Time
Date	201212
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	VFR
Component
Aircraft Component	Fuel Quantity-Pressure Indication
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 58 Flight Crew Total 1170 Flight Crew Type 58
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Fuel Issue

DA40 pilot experiences a rough running engine at 7;500 ft; switches fuel selector from the right tank to the left; and diverts to the nearest airport. Low fuel and an inaccurate fuel gauge is determined to be the cause.