99 honda civic erratic idle

[craig57]

just purchased the 99 civic 3 months ago it an fine. Let it sit just got time to put it on the road now fired it up yesterday and once it warmed up a bit the engine started to idle erracticly in park. in drive it is fine, u rev it slightly in park and it is fine, just when it idles it does this n park.

it has 187000 km 1.6 liter engine with ac
no check engine light is on

all electrical connections look good
all vacume hoses are in good shape and connected

any ideas were else i can check or what may need replacing

[danielsatur]

Check, clean Idle Air control (IAC), and air filter.