After a round of terrible running combined with the Restricted Performance light coming on, I took the wife's 2000 XJ8 to the parts store and had the codes read, confirming my suspicion that an ignition coil is going bad. The code reader said it was the "D" coil, hence my question. How are they designated? Which one would be position D? The last time this happened, I took it to the dealer and had it fixed. I'm going to tackle the job this time. Any help is appreciated.
Physical cylinder assignments for V8.
Tran
4 8
3 7
2 6
1 5
Fan
Do a visual inspection on the COP, and make sure there's no oil, or rust residue on rubber boot.
The rust residue is evidence of water leaking through the COP cover, and the oil is from a leaky spark plug boss seal. The contaminated COP can cause misfires, you can use a CRC electronic cleaner to clean COP'S.