Fellow Jag-lovers, I was experiencing engine surging during coast-down as noted by Nick in this post from the archive:
I was also experiencing delayed reduction in engine RPM when coming to a stop, to the point it was taking a noticeable amount of additional braking pressure to bring the car to a stop. Not good! I removed the air intake and the throttle body and found the EGR port was heavily encrusted with carbon and, for lack of a better term, burnt crud. It didn’t appear completely blocked, and I was not getting a check engine light (and no VCM code). I gave the port a good cleaning with electrical cleaner and a round wire brush of the type used to clean battery cable connectors. While I had the throttle body (and hence the throttle position sensor, or TPS) off I cleaned the connector with electrical contact cleaner and also flushed it internally by drilling the two holes and using the thin tube with the electrical contact cleaner as has been described by others on this forum. (Don B has an entry in the old J-L photo album about this at http://www.jag-lovers.org/snaps/snap_view.php3?id=1383323851 but unfortunately, at the moment , the full-size pictures are not visible.) My car is idling more smoothly now and the engine is no longer surging. I don’t know whether that EGR port had ever been cleaned in the car’s 24 years and 180,000 miles, but I have not cleaned it myself in the last 17-1/2 years and 105,000 miles that I’ve owned the car. Working at a leisurely pace and with my rudimentary skills it took a couple of hours to do the job but it was well worth doing.
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