Ive been getting various codes between 302,and 304 and the corresponding 352 and 354 with the various misfires. New battery installed, new coils, plugs and next is ignition control modules. No idea where they are mounted though. My reader says codes are for cylinders 2, and 4 but Jaguar manual says they are for cylinders 5 and 7. What is the correct cylinder numbering order, bearing in mind this is U.S. spec 2000 XKR. Codes still persisting even though all have been changed.
Misfire used to occur after about 10 miles, now occurs right on start up and goes away after around 8 miles.

I had a very similar problem that was quickly diagnosed (by member RJ237) as ECU capacitor leakage. I found a place in the UK to replace the offending units and it has completely cured the misfire. RJ recommends: Automotive Scientific Inc. | Quality Rebuilt Automotive Electronics | Rogersville, TN for US owners.


Ignition control modules are locate on the bulkhead, either side of the air intake - but it won't be them causing the misfire...
Hope this helps.

Thanks Mark,
I notice on the website that it repairs ECU for 98-99 models
I call about possible repair

Mark,
Attached the cylinder numbering, or see this post by Jim Lombardi:
https://www.jaguarforums.com/forum/x...27/#post498920

Ignition modules incorporated into ECM for 2000 on; others more knowledgeable will chime in with help on the misfire.

Mike

An ECU problem related to internals is unlikely, that was 96-97 situation. But there is a possibility that there are bent/corroded pins at the ECU.

With the battery neg. cable disconnected check the ECU plug carefully for corrosion or bent pins.

It's also possible that the injectors are the source of the problem. I don't like removing injectors, but unless someone has a better idea, try swapping the ones from the misfire cylinders with ones from the other bank.

The reader is almost certainly correct (cyls 2 & 4). Use the correct jag numbering which I see someone has posted and you should be good.

If problems remain I think the jag codes info lists the known causes (as it does for my car) other than the coils themselves.

I've completed a hard reset and after 3 12 mile journeys, it seems to have done the trick - no RP, CEL or codes so far! After some longer running at the weekend I can hopefully put RESOLVED on the end of this thread. Thanks to all who contributed advice.