2000 Rover 25 revving when stationary

dont want to sound silly but is there some slack in the accellerator cable or is it tight as if it is tight then you want to put some slack in the cable and see what that does to the revs as the throttle may be partially open

take of the air intake pipe from the air filter box and check the venturi is not carboned up also manually operate the throttlw without the car running from under the bonnet does it feel like the operation of the throttle is tight if the venturi housing is plastic you will probably find this is the problem as they wear causing the throttle not to return properley see if you can manually return the throttle by hand under the bonnet you may feel there is a tight spot once returned it should idle correctly and then you know this is the problem

its the air bleed valve.

turn on the ignition to the 2 position pump the accelerator 5 timer - you will hear a clicking noise. then turn the ignition off. leave for 30 secods and it should solve the problem!