Screwed up idle
 

Okay, my car is going in for service and we're (yes we're, I dont like dropping it off so they can break it, i mean fix it) and I'd like to be able to talk inteligently about this...

my idle has also been screwy, but I hear its supossed to be around 500-350 rpm for an 90 si. mine will do whatever it feels like. today it sat at 1500rpm, and when its hot (like last summer) it danced around 3000rpm. what causes this? I'm assuming a sensor is screwed up, but what is it, and what should I check?

maybe your TPS located on the throttle body or maybe it's your Idle air control valve. Are you throwing codes?? If so, there is a 2 pin connector by the passenger side floor board, there is two wires that you need to make a circuit with and it will flash the SES light and the CEL code, tell me what your code is if you're throwing one and I'll tell you the problem. Also, if you need me to take a picture of the 2 pin connector so you know what it looks like I can :)

a dirty TB or a vacuum leak will cause this again. but 350-500 rpms ? sheesh that's low.

300? mines goin in on friday...mines less than 200 sometimes...

well, I think I read that in the chiltons manual, but it could be bs, you never know. I just need to break down and buy that helms manual...

and no, I'm not throwing any codes related to the idle..the only code I have right now is the o2 sensor, but I've had the idle problem since I've had the car, before the 02 sensor was dying. I'm taking mine in on thurs, and we're going to fix some stuff. Depending on the cost I may have him check that IACV, TPS, and check for vacuum leaks. Thanks guys!

if you aren't throwing a code, then you have a vaccuum hose leak most likely

cool, that narrows it down. thanks, we'll take a look at it!