Hi Folks:
I’ve been working on my 2000 XJ, coil pack. Had a lower inductance on the 2 and 5 coil secondary. Got new coil. Then the error went to flashing CEL (intermittently). It cleared eventually, and later moved to another cylinder when I moved plugs around. So maybe I have a bad plug, but it still fires.
A couple of questions about this setup for anyone who might know:
It looks like an isolated secondary that goes to two plugs. I get 48H between each pair. Does this mean one plug is getting a positive spark and the other a negative?
Does the computer source and sink the primaries ( and the common I suppose ) to keep the spark the same on the power stroke?
It is inductive, right? Not CDI?
Thanks!
HarryHydro

 

Yes, there is a single coil firing two plugs at once with them connected in series with the block providing the connection between them. One has the current flowing tip to base, and the other base to tip. The pairing means it's firing on the compression stroke of one and the exhaust stroke of the other cylinder, also called a wasted spark setup. This is a simple coil setup (not CDI), with battery voltage supplied from the ASD relay and the computer is controlling the ground side of the individual coil primaries to trigger the spark.