Hi Dave,
To help one needs to know are there any other symptoms, other than bad cold starting and a sooty exhaust...Once running at operating temperature does it run clean and strong?
Whatever the cause is, DON"T go buying parts unless based on factual testing to determine cause and effect otherwise you'll end up broke and !Removed! off with your beautiful XJ....
Attached is a PDF that'll give you a better understanding as to what happens when you attempt a cold start, along with how to check each function.
I sincerely would like to give credit to the author (I think on Jag-lovers.com?) but can't recall the name or source..
Laurie
XJ6 Cold Start Check.pdf
