An XJS that has sat for a few years can seem like a problem when driven again for the first drive. Systems such as the AC and electronics may not work right away from sitting. You should drive it for as long as you can, on and off the highway as it may take a while for it to get warmed up and ready for all systems to realize that the car is running again and begin to function properly. I am going to suggest something that you have heard me say before and that is to drive the car for a while and give the oil a chance to lube parts such as the lifters and valves from sitting for years. Unless you know just how long it has sat not driven or even perhaps running, chances are it is longer than mentioned.
I bought one for parts and was told that the car sat for around 6 months but when I arrived and saw the license plate still in place, which stated 2017, and the fuel smells so bad that I was concerned when I placed it in storage until I could have it picked up and delivered. If ever a car is stored away for a while, it is very important to put some fuel stabilizer in the car. I like to put some in the tank when it is less than three-quarters full then fill it as the force and turbulence mix it in very well. If the AC is not working in a car that was sitting around, remember the XJS is over 25 years old and I always repeat the same thing that is normally the cure for several things in classic cars that have many times the original hoses, replace, replace and replace. Now, we are currently awaiting the reproduction results and hope to have resolved in the next two weeks of the oil and gearbox cooling lines which are long out of production.
The main place where the AC on these cars fails/leak is the high-pressure hoses. As well as the bearings and seals on the compressor ware. Bearings in the compressor ware from high use and the seals from age. This is where the AC dye/leak detector is of good use but overall and more than not it’s the hoses from age. The most important thing to remember that is all too easy to overlook is that the XJS no matter what year is 25 plus years old and all rubber must be replaced as soon as you buy the car unless there are service records that show they have been replaced within the last couple of years. And I mean a couple as in two and not ten or fifteen. Also, the instrument cluster may be a little wacky and bouncing around. This may be caused by electrical contact or the need to have the actual individual gauge recalibrated. We are now servicing XJS gauges. So now you can prepare for the spring cleaning of dusting off the XJS and bring it back to life and enjoy another wonderful season of the XJS world.