Hi Guys,
LTNpost on this forum (I’m usually posting about my XJSes on that forum). I finally was able to have a replacement key (and buy another used fob) for Harlem, my '00 XJ8 (black/black, 160K miles), earlier this month. 
She has been in “hibernation” for almost 2 years now, being a non-starter and in storage until I could find a way to have my lost key (my sole one) replaced, which happened later on. 
I tried calling around to all the Jag dealerships here in the DFW area, and unlike back then, for once one of them actually has a Tibbe key cutting machine and someone who knows how to operate it (try Park Place Jaguar near DFW Airport, if needed). That was half the battle, as I also did not know the key cut code for her (hence why it’s always a good idea to decode your key and write the #s down in a safe place, or at least take photocopies of two sides of it). Park Place was actually able to look up the key code online for me by putting in Harlem’s VIN # into their computer registry system. $120.00 later, new key!
So, this evening I had Harlem towed to my apt. from where I had her in storage all this time. I knew the battery was totally bad by now, so put in a new one. However, when I first turned the key on, I knew something else was wrong with her. Before she would crank, but not turn over. Now, she would not even crank 
(I did have a mechanic friend look at her while she was in storage - he opined her starter was bad, and r/red it with a top notch used one, btw). Still no start, though. 
I called another friend to come over tonight and give Harlem a look over with me, as best we could in the dark. He noticed that the shifter seemed rather “loose”, i.e. the handle would glide smoothly through the gear selections on the J-Gate w/o firmly “latching” into any of them. I told him I don’t remember it being like that when she ran (btw, the car was actually given to my late brother by me for his use, I had only driven it myself a handful of times). He tried to get under the car as best he could, and with a flashlight emerged to opine that it looked like (someone?) had possibly disconnected the cables/connectors on the underside of the shifter. 
I have no idea why someone would have done that, except (1) the earlier tech, as part of r/ring the starter (and forgot to reattach them) OR (2) being she was stored behind another car at a residence, and, not having a key to disengage the steering interlock and, w/o a key, the shifter not being able to be moved out of “park”, someone got under there to disconnect them so Harlem could be pushed out of the way to allow the other car out of its spot (?) (and, again, not reconnected afterwards). 
My
friend suggested we try pushing the car while she was in “park”, and, sure enough, she could be pushed, meaning the trans was NOT actually in park. 
Turning the key on again, I noticed this time the error message “gearbox not functioning”, or some such on the dash. I take it that Harlem’s computer was somehow able to detect that the cables/connectors from the shifters were indeed disconnected, and hence the message. (?)
I also wonder if the reason Harlem is not cranking is that, detecting the problem with the “gearbox”, some sort of mechanism activated through her computer was preventing the starter from cranking, possibly for safety reasons, sort of like the safety interlock does if the brake pedal is not depressed when taking the tran out of park. (?) Does that sound plausible?
One thing I did notice whenever I was turning the key on is that I did NOT hear the sound of her fuel pump priming, although the fuel gauge showed at least some fuel in the tank. 
I can’t remember though whether I used to be able to hear the sound (my driver’s door was open tonight) from inside the cabin back when she was running, but I was thinking I did. I know I can always hear it in my XJSes. Even if the fuel pump is not working, I noticed after turning the key on a few times I could strongly smell fuel from inside the cabin. If the pump is not working, I don’t see how it is possible for fuel to be moving through the system. My friend and I looked under the car with the flashlight and down inside the engine compartment, but could see no signs of leakage. dripping on the ground, etc. Very strange. At one point, I wondered if maybe we should disconnect the battery and stop the attempt, for fear of starting off a fire. 
until we knew more about the source of the smell. I then decided to call it a night.
Anyway, your thoughts and guidance please on all the above issues. After we get to where Harlem will at least crank, then we can move on to the non-start condition, if need be. If we can get her to at least crank we can do the usual quick tests to see if current is even getting to the plugs. I can also see whether the tach is pulsating while cranking or just laying flat - if the latter, then possibly a bad C.P.S. involved.
And, secondly, where exactly IN the Tibbe key is the chip located? It appears to just be a simple, skinny, solid (brass?) key with a flat head (growler both sides) on it that is - or at least looks like - the same exact one like I used for my XJ40s and X-300 ? Chipped keys usually have a “raised area” on them where the chip is located (inside). There is no way something could be put “inside” this key. This makes no sense … 
) were auto injury clients of mine like 10 years ago. I wondered why when he handed me the key he asked me “do you still happen to have that old black XJ40?” (Layla, my first Jag - '88 MY) and I wondered HITH he knew about her. 
Something must have changed for the worse in the interim. 
All for stupid want of a key … 
I take it there’s probably no other source where I can have it done cheaper. 
). Based on what he has, looks like once I get Harlem running again I could fix her up to where she looked almost new, on the cheap, absent a paint job. 
Would any of the '98-'00 sets suffice, or are there any major differences you know of among those MYs?