I have a problem with the fuel gauge on my XJS 6.0 V12 coupe. After I have filled up, the fuel gauge shows full tank. But after I've run a couple of minutes the meter has dropped to 3/4 tank. After this the meter seems to work pretty normal down to the red line when the fuel warning light comes on. When I fill up the tank it takes 60 liters. Tank capacity is around 90 liters on the XJS I think.
My mechanic replaced the fuel sender, but to no avail. The mechanic now thinks that the expansion tank is loose so it interferes with the fuel sender and that is why the gauge shows too low. According to him the only way to remedy this is to replace the tank, because you do not get attached to the expansion tank without actually cutting up the gas tank - not a viable solution.
Have any of you heard of anything similar, is a loose expansion tank a likely explanation or could it be something else?
My mechanic replaced the fuel sender, but to no avail. The mechanic now thinks that the expansion tank is loose so it interferes with the fuel sender and that is why the gauge shows too low. According to him the only way to remedy this is to replace the tank, because you do not get attached to the expansion tank without actually cutting up the gas tank - not a viable solution.
Have any of you heard of anything similar, is a loose expansion tank a likely explanation or could it be something else?