My fuel gauge has suddenly decided to read full all the time irrespective of how much is in the tank , not sure where to start, any help is appreciated please . 1992 XJ6 sovereign . 4.0 litre.

Thanks ,
Paul

Submitted by zurdo_1@univis… on Wed, 06/13/2007 - 21:37

if the car has sat for a while, the float(s) get stuck, well at least it happens in my '84. The gauge goes crazy trying to decide how much gas to report, until it stabilizes after driving it a while, somehow the float(s) get unstuck by themselves. And like your car, it's very ramdom.

I can't help wondering if this has any relation to the new gasoline formulations, 1 formula for winter, 1 for spring. As far as my gut feeling goes, these new gasolines seem to be very "corrosive" to fuel system parts.

Submitted by pconnor@shaw.ca on Wed, 06/13/2007 - 20:23

Thanks for the input , I have a feeling it was a stuck float though as I filled up ready for a long trip at the weekend and as the gas was used it seemed to be working properly and is still dropping accordingly . I'll keep a close eye on it in relation to the miles I do and hopefully it was a one off glych , appreciate the advice .
Paul. My Cat came back !

Submitted by zurdo_1@univis… on Tue, 06/12/2007 - 20:40

generic help: I would substitute the gauge to see if a known good one does the same thing. Yes I know, where do you get another? a salvage yard. If it does the same thing, then the gauge is not it. Then you would want to check the wire connections to the tank, and as a last resort, the float could be stuck, that would mean removal and inspection. When removing the tank's cover, you need to use brass tools, to avoid any spark which could cause an explosion. Fuel vapors are invisible and more dangerous than liquid fuel. Also, you will need to de-pressurize the system before working in any part of the fuel system. A service manual is a must.