i just got my 92 ls smoged and it did not pass becuase it needed a gas cap and was a out of time. i timed the car and got a new gas cap and took it back. it passed. now when the car is cold it idles at like 3000 rpm and drops back to normal. it keeps doing it till its warmed up. after its warm it goes back and forth from 1500 to about 9. I thought it might be a vacum leak but i cant find anything? has this happen to anyone else? what might it be?

 

Assuming you didn't knock any vacuum lines loose I'd look towards the fast idle thermo valve (fitv). If you search for that you will find a ton of info on cleaning and adjusting it. The best part is it's free so try it and see what happens.

 

Try this - https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/