The AC unit in my 1985 xjs is toast. To facilitate working on the engine, I've got it tucked up against the bonnet. It's had me wondering, is an AC removal as simple as disconnecting it? I feel I really don't need it long term.

 

Your air conditioning system is plumbed in such a way to include a fuel cooler in the engine bay and the air system inside the car depends on the AC unit to defrost and demist the windshield by removing condensation even though it blows warm air on the windshield. There would be issues to deal with if the AC system was disabled, but the car would still usable.

 

Speaking of which, have you noticed that fuel cooler is cooling the return side? Am I missing something here? My A/C is removed, however it was in perfectly working order, I just took it off for rebuild and never put it back on.

 

Fuel coolers on our Jags are not for better performance. They were installed on the return line to keep the fuel in the tank cool so as to reduce vapor. There evidently was a problem with vapor lock since the Jag fuel pump supplies much more fuel than is needed and a lot is returned to the tank causing it to heat up. Kirby Palm also suggests that it may have been added to reduce excess vapor for EPA regs as well. The convertibles have two tanks and I have heard that some have modified their ac system to run all the time due to the vapor lock issue...I have no first hand knowledge of this though. It would have been nice if the Jag engineers could have figured out a way to install the fuel cooler on the supply line for enhanced performance...but that would have been asking too much of the already overworked team involved in so many other complexities designed to make the XJS....run.