3.5 V8 disco, idle seems to be a bit high. Used to be fine but its started misbehaving over the last week....

when i let off the throttle the revs dont drop below 1100rpm ish, after a short while of idling high it drops a little but not as low as it used to.

I checked the cable and the pedal (i had a problem with the rubber sound proofing catching on the top of the throttle pedal, a little trimming sorted that) theres plenty enough play in the cable, any ideas what could be causing the random idle??

Thanks chaps

Sticky stepper has to be prime suspect. Lots about this, do a quick search.