I have a 2000 XJ with a 4.8L stroker. I went out the other day to take it for a spin and it would not start. It would just crank and crank, would not fire. I immediately suspected the CPS. I went out today to see if I could test it with my multi-tester. I have another CPS off a different year that I know is good. I tested that and tested my CPS, they gave similar readings. I reconnected my original CPS connector and hit the key, it cranked right up. It ran a little rough, but it did run. I let it sit for a few minutes, then started it up again and took it around the block. About 5 minutes into the cruise it threw a check engine light. It continued to run no problem. I didn't keep driving very long because I didn't want to get stranded. I don't have a code reader so I can't pull the code.

Does this sound like CPS symptoms?

 

Sounds like the CKP connection - tear it apart and clean it.

The later CKP, as I recall, is a Hall Effect sensor. HE sensors tend to either work or not work. If it's intermittent, the problem is in the signal train somewhere - so tear open any involved connections and look for crud.

 

Good to know. I read during my searches that disconnecting my CPS would reset my computer. I don't know if I fully believe that. But there were several accounts of people unplugging them, plugging them back in and having them crank right up. Like you said, could be a faulty connection.

Doesn't explain my check engine light though. The engine is brand spanking new, everything in it is new, all O2 sensors new etc... It didn't throw CEL's when it was running before. Now it does after a no-start. Strange.

 

do you put both red and black leads in the CPS going to the flywheel? or one to ground? I just shoved mine in the connector and cranked it, no reading... but it's starting when plugged in. going to get the wife to help me tonight so I can play with the leads....