Replaced Ignition Coils - No start
 

I developed a misfire a couple weeks ago so I bought a full set of ignition coils for my '96 XJ6 from Japthug on the forum here.

I replaced all of the coils today along with the spark plugs. The plugs are Champion RC12YC as RC12YCC is no longer available. The gap is .035"

I went to start the car but all it will do now is crank. No starting at all.

I made sure the best that I could that all of the coils are seated correctly. I disconnected the battery for about 10 mins to reset everything. Still nothing.

I'm stumped.

Anyone have any ideas?

Also, since I disconnected the battery and reset the computer, is it possible that I need to let it crank for a long time?

Is there any danger in cranking for an extended time?

Thanks

I also replaced all coils (96 VDP) with the same, back in the summer ..like you, I thought I had properly seated them all. However, it started very hard and ran badly. I then removed them all and sprayed silicone around the boot tips and reinstalled. Started instantly and ran smoothly.
Worth a try? Just don't use the evil WDxx....rots the rubber!

What plugs are you using?

I'm trying to see if these RC12YC's are slightly too thick in diameter. They might be pushing the spark plug boots off.

I'd also installed new RC12YC's....as far as I know there's minimal difference in insulator diameters ......

I am at a loss.

I have installed and reinstalled everything 3 times. Nothing.

Hate to ask, but having been in similar nightmares in the past....did you do any other work on the 12v wiring to the coils? It's so bizarre that it won't run on even 4 cylinders badly ....

In the same vein, you might want to check the RH Heelboard Fuse Box, fuse #10, which is the 5A supply to the coils, amongst other things .....:-)

Uh-oh....Jaguar's sense of humour again ....the coil fuse (same number ) is in the RH Engine Bay fusebox....
Which of course is much more logical ....but the Jaguar Manual Power distribution wiring shows the fuse at both the Heelboard and the Engine Bay....
Which proves that when all else fails, ignore the instructions ....:-(

First you will have to check if the coils spark.
You could pull off the No.1 coil about 5-10mm and have someone crank. If the system works right you can hear the coil sparks (clanging noise)
Or you can pull of the coil, remove the coil boot and let the terminal be close to the body ground and have someone crank. In that case you can visibly see the spark.

If it doesn't spark, it will be either a ignition coil relay, ignition positive relay, or a crank sensor.

Looks like the metal springs that connect the top of the boots to the coils were compressed a little too much and were not making contact with the coil.

I pulled the springs a little bit to stretch them and installed the boots separately from the coils. All is well.

A very frustrating experience, but we all will avoid the same strange problem thanks to you reporting on the solution.