A friend's 1990 Corvette throttle body is sticking and not falling down to the correct idle speed.  Is there suppose to be a return spring on the throttle body linkage?  Yesterday I found a spring that fit and corrected the problem but I'm not sure that was the correct thing to do.

i might have had the same problem with mine. if i adjusted it for the low idle like you are supposed to the throttle would stick. if i turn the adjustment up a little it wouldn't. i replaced my throttle body and don't have the problem anymore. sounds like a case of old age setting in.