Thanks Gents

This is interesting , and I’d like your thoughts on an issue I am chasing , and whether this may be the issue.

I have a 9/87 XJSC with a manual 5speed in it, I have been chasing for some time, and annoying gremlin, that I wonder if the absence of the above modification ( I’m not sure whether its been done or not ) could be the cause of.

When driving lightly , and approaching a roundabout , or bend etc, and I back of the accelerator and ‘coast’ through or around bend/ roundabout, upon re- applying slight throttle, at the very first application I get an annoying miss/ hesitation / jerk from the engine, and then the car is off again, if I drive spiritedly around said bend / roundabout, keeping revs up with a blip of throttle and higher revs, no such, hesitation / miss / jerk occurs.

Could the absence of above modification be the cause?