Ugh, feel your pain...I recently got rid of an XJ cuz I had so many intermittent problems....as you mentioned, CPS, and I fixed a few wires that were cracked and grounding...a TPS, tested some other sensors and found them to be good...just wore out on it - sold it.
Thing that sucks is that I feel the PO dumped it on me knowing all of this...I was just "lucky" enough to test drive it when it was running well - it started acting up as soon as I got it home, nickel and dimed me all winter - sold it in the spring. I was UP FRONT and CLEAR w/ the buyer - he was all over it cuz of the condition anyway, says he'll just fix it - he keeps texting me like I have the answers
No, Bozo, you got a deal on it cuz I was tired of it
Probably a damn wire somewhere, dude...good luck, I don't envy you!! Take Justin up on his beer offer - he and Sam are the XJ Whisperers