I was discussing the same subject with another XJ owner; He did away with the Air Pump system, (everything related to it), and now he's going to remove the Fuel Cooler system. In my '84 XJ-6, those systems are there just like they came from the factory. My opinion is that they were installed for a reason. I am not an engineer, so trying to outguess them about their reasons for adding a Fuel Cooler or Air Pump is preposterous. It's one thing to ADD improvements like making the sidelights act like turn signals, or replacing the air filter with a K & N filter, or adding seat heaters; But it's another to start dismantling away at the integrity of the engine sub-systems. Why does the fuel need to be cooled? Only they know. It's a Jaguar after all, not a '57 Chevy.