Well, got a strange one here!!
Started her up this morning, and on startup noticed the REV needle stick at 1000 RPM. Drove off, and it juddered up to 3,000 and stayed there even when I changed gear!

It kept repeating this until the inside of the car was warm. This was first thing this morning, and now it's warmer out, it's not doing it. Seems to stick in cold weather only, so chaps, any ideas?!
Cheers,
Greg