Check the routing of the accelerator cable and ensure it's not binding. Look at the throttle body and check it's not gummed up (it would have to be really bad to bind) I don't recall if there is a return spring on the accelerator pedal like the brake. Check for one.
Yes check Idle control to see if the valve is operating correctly. I think I cleaned mine with MAF cleaner years ago. Of course check for cracked hoses or loose clamps.
Does the car have any history of cooling issues?....
Let us know how it goes...
