Idle Dances around.

[grans0o]

My car is completely stock, I haven't even done any free mods yet. I notice that when my car isn't fully warmed up and I drive it for a bit and then stop for a stop sign or something, my idle dances around going... up down...up down... It will do this about 4 times and then stop. And after I have been driving it around awhile my idle will stay steady. I also think my idle is kind of high. When I first start it up when it is cold outside, it will hold at 2200 rpms for quite awhile and drop to around 1200 rpms where it idles at while warm. What sort of problem do I have?

 

[troysevo16]

Very simple problem to fix could be a couple things, and yes it is normal for it to idel high when you fist start the car. Ok here are a couple things to check for first there is a screw on top of the throttle body its called the biss, make sure its there and screwed in good, if thats not it check and make sure the egr valve is not leaking air or any lines attached to it are, if thats not it try cleaning the throttle body with some carb cleaner, last and most costly to fixs is the isc this is the lower sensor on the throttle body you can test it with an ohm meter, chek the resistence between the pins 1+2, 2+3, 3+4, 4+5, 5+6. if any read more then 30 or so ohms thats your anwser. oh and this problem is called idel surg

 

[grans0o]

What about my normal idle when it is warm, isn't 1200 a bit high? Is that pretty easy to fix?

 

[xantblazex]

Yeah I'm having a similar problem. When I first start the car and drive around, the idle will not maintain and will drop the RPMs to 0 when I come to stop (neutral / foot on clutch). After a while it warms up and maintains.

But similarly, i had a few incidents (4) where the car didnt start at the first turn of the key, took a while of me holding the key while pumping the clutch to finally start it. I just walked home because my car didnt start this time. My first guess is the starter went, but then since i already have this throttle or vacuum line problem , im wondering if they could be related and its not the starter.

Anyone with some ideas please help.

 

[troysevo16]

start your own thread ^ 1200 is a little high try tighting that screw on the throttle body the biss that should fix it, but 1200 is nothing to worry about if the "biss" is not tha anwser to your problem.

 

[grans0o]

It idles perfectly smooth now, my BISS was screwed pretty much all the way out. I read a vfaq on it for troubleshooting idle surge. http://www.vfaq.com/mods/wayback/BradBauer/engine/surge.html
I tried the first thing on the list, replaced the O-ring on my BISS screwed it back in and backed it out 2 turns and now it idles at the 750 rpms it should with NO surging. Thank you troysevo16 for helping me out on that.