A few months ago, I purchased off E-bay, a crankshaft position sensor complete with one of Andy's brackets at a good price. Clearly the parts had been on a vehicle before. As many of you know, the sender must be considered a service item since they fail and that makes the vehicle a roadblock if you are unlucky! Well, the inevitable happened and my car refused to start one morning. They was not even a twitch from the rev-counter as I cranked it! So, I changed to the newly purchased used sender and Andy's bracket. It was a struggle since access to the part is somewhat tight. Anyway all was well and I have been pleased with the car - until yesterday.
I was driving quickly on the *** Chester Bye-pass, when there was a severe misfire and the check gearbox warning lamp illuminated. The car slowed, but I managed to coax it to the next exit and pulled up to a halt at traffic lights. The tick-over was fine, so I drove slowly, I was now in a 30 mph limit, to my mates garage. I turned off the engine, then on again - all was well, the warning lamp had extinguished and the engine revved normally. So I drove home through Chester to within a half mile of home when the severe misfire returned, and the best speed I could maintain was 10-15 mph. The car died as I turned into my street. It would restart, was very, very lumpy and would stall as soon as I asked it to progress. I walked home, collected a mate and my '76 XJ6, and towed it onto my drive. It was now dark, so let it fester overnight. This morning, I got out my analyser - it refused to connect to the diagnostics of the Jaguar. I tried my new Ford - it connected perfectly - no codes displayed.
Undaunted, I decided to change the position sensor again - for a new one that I bought after installing the previous one. Again a struggle, but I have learned a little, and the car now runs perfectly again!
So, does anyone know why they fail? There are no moving parts, the wiring is undamaged, the area is clean - what is the life expectancy? My car has covered nearly 100 000 miles. Any comments? I will order a new sensor soon. Further, I still have the gearbox warning light illuminated and need to turn it off and clear any fault codes , but cannot since my analyser will not lock on.

 

They are a very simple device with no moving parts. The answer has to be poor quality manufacturing. I have only ever used the genuine Jaguar part and my most recent failure occurred just more than 1 year after replacement but only a few thousand miles. Next time I will try an OEM version - cheaper and couldn't be any worse. You don't see these problems to the same extent with other manufacturers.

 

I have now tried an ELM device and Torque - all fault codes removed, all warning lights extinguished. I don't know how to use all the in time diagnostics but will find out soon, hopefully.