Astra Mk4 revving problems, any thoughts?

[Munks]

Hi guys

I have a Mk4 astra 1.8i 16V which had the usual throttle body issues of cutting out at low revs, this was remedied by cleaning the TB. Now the engine revs jump around from about 1500 to 2500 once the engine has warmed up. Has anyone had any similar experiences, or has any ideas what to do?

Thanks

Munks