My XK140 has a suspect fuel gauge. We can fill the tank and the gauge shows full but drive 20 mile and stop, then when ignition is turned on again the gauge shows empty.


I would suspect its the tank sender unit. Is it easy to test this?


Any advice appreciated, thanks. Jerry

 

If you can access top of tank thru boot yes. Or if sender is mounted on side of tank (unlikely). Otherwise you will have to lower tank to access sender. Sender float may be suspect as any alcohol in fuel really degrades the floats. If you pull sender check if it works by hand then replace float or sender. I had both a 120 and 140 and do not remember if I had to drop tank for access.

 

Have you tried just tapping the gauge? Sometimes the needle sticks on my 120 fuel gauge and a little tap fixes it.


Just a thought.