Yeah yeah yeah, I know. ANOTHER no start post. Hear me out though:

Highlight: Car had to sit for a few month while I was out of town, ran just fine when I left but doesn't want to start now. Cranks just fine, seems to have compression, has fuel, no ignition. Also I've noticed that there is no CEL on when cycling ignition and attempting to start. No coughing sputtering or any signs of life. Also, just for the record, before every testing session the battery was topped off.

Here's what I've sort of eliminated:
-Fuel:
-I can hear the fuel pump run and have fuel to the regulator
-No response at all to a couple shots of ether
-Yes, I reset the inertia sensor
-Yes, I put more fresh fuel in but the stuff in there didn't smell bad
-Because I have fuel to the rail I'm eliminating clogged fuel lines or filter. I considered clogged injectors but I'd have a hard time believing ALL SIX injectors are completely blocked all at once.

-Plugs/coils:
-I took out the plugs and coils and the plugs aren't fouled and the coil boots aren't torn or anything. Connections all appear to be in good shape.
-When everything was out I checked to make sure it wasn't flooded or anything and it was not
-I have a hard time believing ALL SIX coils would go out all at once (I guess they are Lucas so you never know...)

-ECU:
-Removed connections and there are no signs of corrosion

-BPM:
-I replaced it with a used unit about 18 months ago. I don't remember if it would crank or not when the BPM was bad but I suppose this could potentially be the problem again, but I would kinda doubt it.

-CKPS:
-I do read RPM on the tach when starting. This was replaced about 3 years ago with a non Lucas part, so I popped on a junkyard unit that was probably good (car was wrecked so I assumed it had to be running when in accident) to no avail.

-Relays/fuses:
-I swapped the relay in the front right engine bay fusebox with the rear window defroster one, again to no avail
-I went through and checked every fuse in all 5 fuseboxes, again to no avail

Here's my current line of thought:
-When I did the BPM my security system went a little wonky. It didn't chirp anymore afterwards, the red blinking light on the dash when locked stopped, and the red light on the center control switches stays on regardless if the doors are locked or not, and pressing button does nothing. Not sure what role this would play, as I know the US cars haven't got immobilizers.
-I have read a couple off handed remarks about the presence of the CEL when starting. Mine does not come on at any point in the starting process. I don't really remember if it did before or not, it's been a while since I have been able to drive it. Again, I'm not really sure what role or function the CEL serves in the starting/ignition process but thought it was worth a mention

 

no CEL when cycling ignition a car with the GEMS means its immobilizer related. on US cars with a working bpm the only thing that would stop it is a full alarm state

 

If the CEL does not come on at all when the key is first turned to Pos II then there may be an issue with the bulb. I've had that (dirty contacts on the board). The bulb not working would not prevent starting but I would check the bulb and socket to get it working properly and exclude it from the equation first.

 

@xalty As far as I understand if the BPM is bad then the car will not even turn over. I've never heard of a non immobilizer car referred to as being in a "full arm state", could you further explain what all this entails. Thanks.

 

To save wild guessing, do you have a code scanner? If not, it seems like there is no spark so car can’t fire up. Although X300 in the US is not equipped with immobilizer, a hard reset might clear up any conflicting signals that might be inhibiting the starting process. The other suspect is the BPM or bad contact somewhere.

 

The CEL must be lit to enable engine cranking. Yours isn't but it cranks. That's odd. Good suggestion from Brendan to check the bulb!

"Full Alarm State" is lights flashing, horn honking and siren blaring. There is no mistaking a tripped Jaguar alarm system! Only way to reset it is to put the key in and turn to Ignition On. Then all's well....

You'll want to check the black Ignition Coil Relay. It's the innermost of the row of 3 (one is a dummy shell) just in front of the right-hand engine bay fuse box. The one next to it is for the screen wash. Swap them.