Narrative:

I was flying a PA-32 turbo lance to ZZZ. The time enroute was 3 hours. The fuel endurance at my altitude (7500) was 4.5 hrs. The PA-32 has a split fuel system requiring switching tanks approximately every 30 minutes to maintain fuel balance.for the first 1:45 of flight; I switched tanks roughly 4 times and should have had an even balance of fuel. There is no way to transfer fuel between tanks. This particular aircraft was equipped with standard fuel gauges (analogue; not very accurate) as well as a digital fuel flow indicator which tells the pilot which wing is providing fuel.around 1:30 into the flight; I noticed that the right wing tended to dip to the right with the autopilot on. The aircraft would then correct itself. I adjusted the trim several times thinking that there was a rudder trim issue; but it didn't correct itself. About this time; I realized that even though I had the right fuel tank selected; the digital indicator showed the engine feeding off the left tank. The left tank fuel gauge showed more than 20 gallons remaining (less than 1 hour at altitude; 30 minutes in pattern). The right tank still showed full. I turned on the electric fuel pump; and attempted several transfers from tank to tank to no avail. At this point; I determined my position and looked for the closest airport with fuel service. It was a [weekend]; and I was concerned that the closer airports would not have fuel available and I would be stuck. I then called ATC and discussed my situation. I told him that I was having a fuel issue and requested assistance in finding a close airport with fuel available. Another (I assume) local pilot [responded] that ZZZ1 has a self-service fuel system. This airport was only about 15 miles away; however there was an undercast layer covering the airport. The AWOS reported approx. 1;200 overcast. I was not able to descend VFR to landing. The aircraft I was flying was instrument certified and current; as am I. I requested an IFR clearance from ATC for the localizer approach. He cleared me as requested. I landed without further incident. Upon landing; I discovered there was less than 20 minutes of fuel remaining in the operative tank. The other tank was 3/4 full.

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Original NASA ASRS Text

Title: PA-32 pilot reported a fuel feed issue resulted in a diversion for evaluation.

Narrative: I was flying a PA-32 Turbo Lance to ZZZ. The time enroute was 3 hours. The fuel endurance at my altitude (7500) was 4.5 hrs. The PA-32 has a split fuel system requiring switching tanks approximately every 30 minutes to maintain fuel balance.For the first 1:45 of flight; I switched tanks roughly 4 times and should have had an even balance of fuel. There is no way to transfer fuel between tanks. This particular aircraft was equipped with standard fuel gauges (analogue; not very accurate) as well as a digital fuel flow indicator which tells the pilot which wing is providing fuel.Around 1:30 into the flight; I noticed that the right wing tended to dip to the right with the autopilot on. The aircraft would then correct itself. I adjusted the trim several times thinking that there was a rudder trim issue; but it didn't correct itself. About this time; I realized that even though I had the right fuel tank selected; the digital indicator showed the engine feeding off the left tank. The left tank fuel gauge showed more than 20 gallons remaining (less than 1 hour at altitude; 30 minutes in pattern). The right tank still showed full. I turned on the electric fuel pump; and attempted several transfers from tank to tank to no avail. At this point; I determined my position and looked for the closest airport with fuel service. It was a [weekend]; and I was concerned that the closer airports would not have fuel available and I would be stuck. I then called ATC and discussed my situation. I told him that I was having a fuel issue and requested assistance in finding a close airport with fuel available. Another (I assume) local pilot [responded] that ZZZ1 has a self-service fuel system. This airport was only about 15 miles away; however there was an undercast layer covering the airport. The AWOS reported approx. 1;200 overcast. I was not able to descend VFR to landing. The aircraft I was flying was instrument certified and current; as am I. I requested an IFR clearance from ATC for the localizer approach. He cleared me as requested. I landed without further incident. Upon landing; I discovered there was less than 20 minutes of fuel remaining in the operative tank. The other tank was 3/4 full.

Data retrieved from NASA's ASRS site 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.