The CPS as small as a component it is, it's as big in having your car run.
Years ago I spoke to a jag owner that said he carries an extra one in his trunk. I have come to believe. If you haven't become familiar with the CPS, take the time and do so and/or become reacquainted with it. If it fails at all your car will stall, at anytime, any speed, anywhere. If it's dodgy/dirty/intermittent so as your car will run.
It is the part that gives the coil spark to the distributor and out from there. If it fails, becomes unstable so will your spark. Spark, good strong spark, along with proper fuel pressure and your jag will run amazingly.
If you haven't tinkered with your Jag, and may be apprehensive about anything mechanical, I invite you to begin by removing your own CPS. It is in a position that gives a simple challenge, but easy as changing plugs once you've done it. A T30 with a long extension is all it takes. There are tons of posts on it here as well. Keep it clean, revisit it when you are inside your engine bay regularly. And maybe, just maybe you too will keep a well known working one in your trunk as well. It's cheaper than a flatbed.

 

Wow! Truer or more pertinent words were never spoken regarding Jaguars.

I have been at this since 1974, and with Jaguar since 1989; and pride myself in maintaining my cars well and warding off failures with preemptive repairs whatever they may be. However, that crankshaft sensor you mention is responsible for the one and only time any car has ever put me afoot; and it was during a vacation, away from home, with my sister and her husband along. It was my 1989 VDP which had been running beautifully, as it always did. We pulled into the lodge at Kentucky Lake to have lunch, shut the car off and went in. Car never ran again. Had to be flat-bedded to Nashville where the crankshaft sensor was found to be the issue. [I have AAA Plus since we travel some, and the driver showed me the odometer and said Plus gets you 100 miles, he traveled 98.8 miles to get me there]

I always kept a crank sensor in that car, along with a socket to change it, until I sold it a year or so after I bought the XJR. I have one for the "R" close at hand as well.

My two cents......

 

Good to know!

 

So true, mrtalkradio

I keep one spare in the trunk to be sure, just in case.

People used to laugh at me when they heard about this, until the day came when the car, which I (as most drivers, I guess) am quite dependant on, suddenly would not start.

I was prepared, not only as I had the sensor ready in the trunk, but I also immediately recognized the symptom of a retired CPS, and knew its exact location and what tool was needed.

I took me approximately 20 minutes from start fail to I had the motor running again.

No reason for not being prepared for this :-)

Karl