Idling Control valve in R Reg Mondeo?

My engine was racing and was told it was a Carbon build-up in the Control Valve.
I have had the part replaced and the engine still seems too fast.
What should the idling speed be for starters?
The fitter who replaced the part told me it wasn't right on completing the job but told me to give it a good run to see how it goes.
I have changed the plugs also and wondered if there is anything else I can do to improve the running of our one and only car.
(OAP so out of the question on getting another car!)

Thanks in advance for any help.