Hi all - just an update....
Took the car to a garage a few days ago, he spent about 45 minutes on it, also testing it with an error code reader or something - but he said it didn't give him any errors, and presumably that's because the specific problem needs to occur 5 times in a row for it to send a code to the computer, but my particular "revving" problem doesn't happen
everytime i hold the clutch down....
Anyway, he didn't charge me for what he did the other day, and i took it in today for him to spend another 40 mins or so trying to diagnose it.
He said something was full of gunk (i don't know what it was, throttle something?? and the idle thingy??
)
so he cleaned that out.
But he's found a problem with a caliber(?) on the front brake which is sticking, and will cost about £90 to fix/replace...
Anyway - it hasn't revved on me so far, so fingers crossed the problem stays away!