Ok, riddle me this, LFGSS car people.
Today I was driving down the M3 to Winchester, I had gone onto said motorway off the M25, so a long, long period of 50 limit.
Out of the 50 limit (during which I had been sure the car had stuttered a few times, but then it had been fine), and I found that the car would only drive at a partial throttle opening - put foot down hard and the car choked, juddered, starting losing speed.
Back to a partial throttle opening and it was fine again.
Felt very much like I was sucking a hose closed when I opened the throttle.
Interesting thing is that this started to happen at exactly the same place on the motorway that it did last time I did this same journey.
I made it to Winchester, pulled off the M3 onto Spitfire link, the car barely made it away from the roundabout - and I mean barely.
Any load at all and it bucked and juddered.
Got home, parked, unpacked, left car for a couple of hours.
I just drove it up to Sainsbury and back and it's fine again.