Hello
I have had a electrical fault on my xjc where it will randomly cut out and not restart, I took it to a mechanic who diagnosed the fuel tank dashboard switch as faulty I have replaced and it now definitely works as the car runs rough on the left tank and smoothly on the right (likely old fuel the cause) could a faulty switch cause the car to cut out or is there likely to be another underlying fault it's had points and plugs replaced recently and all contacts cleaned. Cheers
Would love to get the old girl out tomorrow fingers crossed

 

Is the car running properly on one (right) tank or does it cut out still?
If you've got cruddy fuel in one tank it will affect the running as it will get into the carbs bowls. Shouldn't go instantly from running smoothly to rough at the press of the button for the same reason.
Maybe a poor fuel pump??
Dodgy connection on switch reffered to in https://www.jaguarforums.com/forum/x...ts-out-116791/ ???
On a side note, don't throw the old switch away, they're easy to clean, re-grease and reassemble.

 

The car takes about 30 seconds to change idle I'm assuming this would be about right but maybe it's just a red herring. I will investigate that earthing solution. Cheers