Fuel Gauge Stuck on Full

[thstone]

1997 Boxster.

For the past year, I've had the problem where the fuel gauge displays 3/4 tank anytime that the tank is 3/4 or more full. It seemed to work normally below 3/4.

Now, the fuel gauge seems to be stuck on full. Last week, I drove the car in the canyons and when I got back the gauge was still on Full - and took 8 gallons until auto-shutoff. Drove it again in the canyons this week and it should be down to at least 3/4 and still shows completely Full.

The gauge moves up and down when I power on/off the car.

Ideas? Looks like its time to pull the sending unit...

[particlewave]

My guess, sending unit is sticking or worn.

[BYprodriver]

Originally Posted by particlewave

My guess, sending unit is sticking or worn.

Yes that or if battery power is lost it can lose it's calibration. I don't know how it can be recalibrated without determining current fuel level.

In 2004 I was running time trials at Streets of Willow in my 2000S, my engine slowly lost power & stopped. I believe the gas gauge showed about half full. I thought it was an electrical problem but gave up & had it towed to Pacific Porsche. They replaced fuel sending unit & recalibrated after adding $10. gas Total charge $ 560. sending unit was $175 part# 996-620-808-00.

[thstone]

Problem solved by replacing the fuel level sending unit. The old unit arm was "stuck" in the full position.

Details in the Spec Boxster thread: Spec Boxster Build