Poor Idle Speed When Warm
 

My car always seems to have a difficult time idling at a above 900 rpm. When the car is cold, the idle hangs around 950, which feels right (but, I think it's suppose to idle higher when cold?).

However, after driving the car around and getting it nice and warm, when I idle, the rpm drops down to around 600 and I can keep hearing the engine sound like it's struggling as the rpm fluctuates up and down between a 500-700 rpm range, which it eventually levels out to around 700 rpm.

Anyways, I'm thinking I should fix it soon because I'm tired of the struggling sound and vibrations when the car is warm and idling.

Does anyone have any suggestions as to where I should be looking? I have plans to replace the following during spring break:
1. ISV - add in the venturi delete while I'm in there
2. TPS
3. seals on the TB - Arnnworx's kit

Anything else I should look at?
Thanks

A bad TPS could cause you some problems. Have you tried backing out the idle adjustment screw a bit? 600 rpm idle is really low. I get about 950 both cold and warm, though maybe its 1000 cold.

If you want to come by sometime, I can pressure test your intake with my air compressor and that'll find any leaks you have.

I vote for idle stabilization valve. Had to replace mine a few months ago. Idle speed was too high when warm and too low when cold. Unfortunately, valve costs about 150 bucks.

You should hear a click from TPS just as throttle closes. Like IanS said above, that could also be the problem.

You could try pulling the idle stabilization valve and cleaning it if you find out thats the problem. I believe some people have had success with that.