ridiculous idle

[NateTheGreat]

hey guys. i have a problem with my idle... it only happens when i start the car. it shoots up to 2500-3000 rpms then sits there for five seconds then it goes down to idle surge between 1000-1500... when its warm though it idles at 850-900 rpms. about normal... any suggestions?

 

[Trav83]

Do you know how to check your sensors with a voltameter? Try checking your ISC motor, TPS sensor, idle control switch, and MAF sensor and see if they are reading correctly (or working at all). The #1 culprits are the ISC motor and the TPS sensor. Also what have you done to your motor, as far as emission elimination?

 

[afsdsm]

A vacuum leak could also cause a idle surge, try a BLT also.

 

[Rob10_99]

An easy way to test your IAC, pull out those 3 screws holding it in. Cycle the key on and off, it should go all the way in and all the way out.