need help-high idle but choke works fine??

[motornutz]

im looking for a little help on my 89 accord dx. it is carbed and has an idle problem. with the aircleaner off and the engine cold the choke is closed. when i start it the rpm jumps to 2500 and the choke opens slowly until warm then it is open completely. while it is racing if you stab the gas it drops the idle down to 1700. it drives great and acts as it should but still idles at 1500 when you come to a stop (in gear). after you shut it down it diesels real bad but is easy to start up again. im new to hondas and am not sure what else this could be. thought maybe idle set to high or a coolant temp switch. any help would be greatly appreciated.

[89accordex4dr]

Have you checked the timing?

[Kabuki]

Sounds like a vacuum leak, or possibly some crap in the carburetor. Common vacuum leaks I see are the diaphragms. Hot Air Control Valve Diaphragm, Vacuum Advance, Choke Opener Diaphragm, and Charcoal Canister Vent Diaphragm. Oh, and of course check ALL of the vacuum hoses.