Irg
You are very correct about owners not replacing their fuel lines when they get old. This is the reason for the fires.
There is nothing wrong with British engineering versus German engineering, just that British, as well as American companies, do not sweat the details like the Japanese and German companies.
The main reason the V-12 engine was switched out for Chevy V-8's was that they quit running! And their owners couldn't diagnose the problem, and neither would the indies. To put it simply, the amplifier for the ignition was located smack in the middle of the V, and literally cooked itself to death. The factory fix for this was to remount the amps in front of the radiator, and from then on, there was no problem. My fix was to purchase a kit from Crane Ignition which includes an optical pick up for the distributor which replaces the Hall effect pick up. It runs sweet.
The other problem which haunted this particular car and had me going in circles!! was the "roll over switch" was being tripped by closing the drivers door too hard! Therefore the fuel pump would not work. (the power to the pump is routed through this safety device) Trouble was, I could not find this switch! It was very unclear where it was from looking at the wiring diagram.
While trying to get a restart at a restaurant in Gilroy (garlic capitol of the world!) on a busy street, I just happened to spot it as I was getting out of the car. There it was, right at the door jamb/kick panel. Apparently it is a very sensitive switch and is conveniently located so the driver can reset it.(just push the button on the top of the switch, and hey presto!)
I bought a beautiful Alfa Spyder this way once. No one could figure out why it would crank, but it wouldn't start! $500!
Sold it the next day for $4500. Pushed the button!
This engine is carried around in an XJ-S, not the sedan, and therefore has a very cramped and hot engine compartment. The fuel lines get so warm, that the factory actually circulates the fuel line through the A/C system to cool it down!!! And therefore, the A/C is required to run it's pump all the time, which contributes to the truly miserable fuel mileage of these beasts. < than 10!!!
But I will tell you what gang, This car handles brilliantly while having a magic carpet ride at the same time. The only other car that does this magic trick are my two 123's.
So there you have it. Jags are not what I thought they were. They are beautifully engineered and constructed cars, which were cheaper than MB's when new. Overly complex and troublesome and expensive for casual owners, which led to early retirement.
I love working on my Benz, hate working on the Jag!