I've been having an idle problem. the last few hrs hasn't been so bad. Here's what's going on. When I drive everything seems fine. But when I stop, my rpms rise to 2k (and stay there for about 1-2 seconds) then drops to 1k and jumps to 1300 (and repeats). I noticed earlier that it didn't go to 2k, instead it rapidly went from 1k-1300 for a few seconds then idle normal. So I've been looking online and found some idle surge symptoms. But what I want to know is why exactly he's acting like this and what you have all experienced (and possibly the most common symptom of idle surge).

It could be that ur isc is busted I remember when mine was surging the isc took care of it and it hasn't come back...buy a new one at mitsu for 300 or at a junk yard I got mine for 16 off a newer hyundai works like a charm

As far as symptoms go my only did it when sitting when the car was warm

Vacuum leak maybe

check for leaks and if dont find any you are just unlucky at the junkyard...if you dont find any leaks just hit the junkyard one more time find a newer hyundai and yank the isc out if its the same, and dont forget to replace the o ring..are u getting any cel i forgot what code it was but mine threw one when it went bad

That's what sucks though kuz I always get CEL (no cat) lol. Do you think a Hyundai dealer would be cheaper? Kuz I've heard of examples where parts where cheaper lol. Hmm, I'll call a Hyundai dealer tomarrow.

Hook up a scanner to your car and check for codes

There's ways to check If your ISC is working ,one of them u start by taking them out and apply power to pin 3 and 6 with a 6volt battery **the square ones** and if the isc rotor thing starts moving then it's good.. I tried this on my car when I thought my ISC was going bad, I got it off a thread on dsmtuners , good luck , also check your BISS screw and TPS and your coolant temp sensor,

I'm pretty sure a bad oring would leak and leaks are never good

idle surge:

Vac leak @ the throttle body or intake manifold.
Low coolant
Bad ICS

Do a boost leak first before you go and spend 300 bucks on a part. And check your coolant.