High idle. 2500rpm! Help!

Hey guys. My 02 k11 revs very high probably about 2500rpm when you start it up and it just sits there. I bought the car cheap as a fixer upper and it has done this from the beginning. Only 43k on it so not like it has much wear. So idles around 2500rpm, can anyone please please help me figure out what is wrong. Thanks
Start with checking if the throttlecable is adjusted properly. If so check and clean the idle control stuff on the tb.