Maniac said:Thanks for that. So I saw a little bounce in revs when you held it at 1000 but it seemed to settle. Mine doesn't, it continues to bounce up and down despite holding the pedal at a fixed position.
Looks like this is an easy way to point at a fault.
Have you got any damage to any air hoses (vacuum system) this was a typical symptom in my past of cars with air leaks on the inlet manifold.
one way of finding a leak is to use brake cleaner (be careful) if the engine speed increases in an area when sprayed than its sucking in to the manifold at that point.
just a thought.