Fuel tank gauge / light

[Deschodt]

Quick one..

"For a 1972 Porsche 911, the low fuel warning light "typically" comes on when the fuel tank drops to about 1.6 US gallons (6 liters) of remaining fuel. This warning system is part of the fuel gauge display and is triggered by the fuel sending unit in the tank. "

That car is the only one I ever ran out of fuel with, a few years ago the light came on, I figured no problem, drove a few miles and ran out of gas ;-) So now I am careful, if it blinks funny I refill.. Still, full fill and my gas gauges indicates like 90% full so I think it lies, and similarly my light came ON today and I could only put in 13 gallons, so theoretically I had 3.4 left ! Call it 3 to be safe. Seems to me the needle is 10% low and never reads Full when full and cries wolf too early (kinda of the opposite of my early misadventure)

Is there a way to adjust the "needle" in the gas gauge to recalibrate that, or is this done 100% at the fuel tank sender somehow ? I have experience with BMW senders from the era, no adjustment is possible just replacement and they all "Lie" differently in that car, it's a float on 2 wires and it goes up/down... Wondering if I can get more precise with the 911..

[PeteKz]

You would have to disassemble the gauge and change the position of the needle. Not easy. Or contact John Bell and ask what he can do.

The sensor might be getting old (original sensor?), or crud is building up on the wires and float contact, causing the light not to come on until it's past the usual spot where it's supposed to come on. You can carefully disassemble the sensor and clean those contacts. But a new one is cheap enough at Pelican that it's probably not worth the effort. After a cleaning attempt, I ended up ordering a new Dansk replacement sensor 3 years ago. It's been working fine.