Crankshaft Position Sensor-good advice

When I first got my 2000 XJ, my best friend advised me to put in a new crankshaft position sensor and keep the known good one in the glove box. That has saved me 2x since 2004, and my Mom once since 2005...the most recent for me being tonight.

It is nice to have one on hand, as it saves you a trip to the auto parts store and could potentially pull you out of some tight spots. Thought I would pass this along. Gonna order a new one tomorrow.

A spare certainly is a good thing to have, but I'm wondering, since I'm now on my second XJ to go over 250 thousand miles on the original CPS, whether it wouldn't be easier to buy a new one and keep that one as the spare.

Six one, half a dozen the other...figure it this way...a defective brand new electronic part is not unheard of....so take the known good one and put it in reserve. What if the new one you have in the glove compartment was defective?

It may sound paranoid...but I think we all have been subjected to outside odds in our wrenching endeavors:wierd:

I do this too, at least when I remember to.

There are a few CPSes over the years -
* 87-90 RENIX 2 wire variable reluctance / coil pickup
* 91-93 (possibly 94) round connector, 3 pin, hall effect pickup
* 94?-96? oval connector, 3 pin, hall effect pickup
* 97?-01 oval connector, 3 pin, hall effect pickup

the two oval connectors with 3 pins are mostly the same, but one has round pins and one has flat pins.

I forget the exact year switchovers across the 91-01 range but they are all exactly the same electrically, Chrysler just couldn't pick a damn connector and stick with it. In a pinch you can splice the connector from the broken one onto the new sensor and run it. themangeraaad did just this, I believe he spliced a 99 sensor with a 93 connector and is currently driving it.

As for brand new vs known good spare - I have heard of a lot of people getting dead sensors from the factory, or ones that died quickly, so I always prefer to take a known good sensor that's been reliable for me for a few months out of service and put in another one that can then prove itself... with my known good spare on hand.