I got a 98 xk8 that code read misfire cylinder 6. I installed a coil and all new plugs. It still read misfire on #6. So I switched #6 and #2 and I still read misfire on #6. I only have a text light so I hook it up to the coil leads and it did light up but not a bright as the other leads? So, would this be a problem coming from the ECM?

 

Sounds like a bad ground for the coil. One wire goes to ECM and one goes to ground. Follow the wire loom back to the ground point check it for cracks , kinks and corrosion

 

See page 35 upper right part of the diagram .

Can you easily swap the position of the ignition modules and see if the problem follows ?

All coils are powered by the ignition coil relay and the ECU provides the timed controlled ground through the ignition module ( new to me )

Inspect the wire connection on the suspect cylinder for a burnt pin and socket .

http://www.jagrepair.com/images/Auto.../jagxk1998.pdf

 

It must be a bad ground. Followed the lines up did a continuity test and seemed OK. Disconnected the battery for about 10mins. Held the negative and positive terminals together for about 10sec. And the bad cylinder reading with away. I didn't think I fixed the problem but it's working for now.