what do you think is the problem with my car? the engine revs good but the idl goes around 700 and goes 1000 when the engine is hot but when im driving for a while the idl rise again to 1400 a few min. back to 1000 and sometimes 700... its so annoying.. should i change the carb or clean the carb or replace the vacuum hose?... by the way.. the car has just been overhaul after sitting for 1 year..