2000 sc1 rpms keep sticking

[niks]

Just wondering if anyone has any ideas as to why my rpms decide to stick at around 2000 when i'm at an idle? Doesn't happen all the time. and if I turn off my car and restart it its fine.. Just swapped radiators, mine just blew a few days ago wondering if that could have affected it somehow randomly? I'm not sure. it drives fine, I can accelerate, stop shift and all that when it sticks just has been happening more frequently.. Wondering some suggestions I can use to fix it. So any ideas?

[zia-czon]

How Many Miles?
Does the idle speed change if you depress the Brake Pedal?
...Check for vacuum leaks first. Check the PCV Valve on the back side of the Valve Cover, the Vacuum hose goes to the Intake, they split all the time and it wouldnt be a bad idea to replace the pcv valve while your there. also check the vacuum at the Brake Booster. If good, go to the throttle plate next and check for excessive carbon build up on the back of the throttle plate and inside the Throttle body, the excessive carbon causes the throttle plate to stick at times.