One more thought. Could a bad alternator or one going bad account for a weak spark?

 

If the COP tester you used is the adjustable type, is it possible you had the gap set too large?

The ignition coils receive a constant 12 volt supply from the ignition coil relay on the wires that are Purple with a White tracer line (at least according to the 1999 AJ27 Electrical Guide. I just re-checked your thread and I don't see that you have told us the model year of your car or the engine displacement, which may make a difference in the wiring colors, especially if you have an AJ26). You can measure the voltage at the coil connectors to see if it is low.

The eight coil ignition modules and the ECM use the EMS LH Ground Stud (EM8), on the left front inner fender, and the ECM also uses the EMS Bulkhead Ground Stud (EM16), on the firewall behind the cylinder head, so it would be worth cleaning those ground studs in particular.

Cheers,

Don

 

Thanks again for your review of my post. This particular Jaguar is a year 2000 base model 4.0 with about 130k. As for the inline spark detect light it does not appear to be adjustable. They are 4 wire coils and although they are sparking it seems weak.

 

So the very first thing I want to do is thank everyone that has helped along the way. There was never any shortage of sound advice and thought provoking questions.
TODAY SHE STARTED AND RAN!
A bit rough at first with a fair amount of smoke from the tailpipes, but considering it hasn't run for over 6 months, not too shabby!
The engine smoothed out and the smoke subsided and I just let it run for around 30 minutes to check for leaks. All was well.
i didn't have my OBDII to pull codes and darkness was approaching so I thought it best to wait for the test drive. That's when I decided to turn it around in its stall and with gearbox fault flashing I labored to move forward but found no difficulty in reverse.
Could this be the dreaded A drum?

 

Jaghag00, first..glad to hear she is running, did you do anything to encourage her revival? For the A drum Q, you may want to review this thread from jimlombardi... https://www.jaguarforums.com/forum/x...-issues-43702/
...you'll need to scroll down and review all the posts as the original .xls doesn't open the links.

 

Not entirely sure this was the reason for starting, but start she did. I want to thank you Highhorse for help and encouragement along the way.
I've had ample time to worry over the major repair concerns of my X308, and have looked closely at Jim Lombardi's links to get familiar with the process.
The expected repair doesn't seem bad at all it's the old in and out that, without lift, transmission jack, garage, I'll stop there as it sounds like I'm whining. Baby steps. I'm so relieved and happy she is purring once more. Mahalo