OK so here is the deal, I fixed a idle issue about a month ago due to the IAC going out on the car. So now the car will idle just fine when warming up but as soon as the car gets to normal temperature it will jump up to 2k rpm and stay there. Now if I go out and drive the car and come to a complete stop it will still idle at 2k rpm. I have the car apart right now doing a new radiator due to the old one cracking. I was thinking along the lines of throttle body shaft seals? Any input would be great.

Car is on GT3076r
264in/ex hks cams
E85
Stock block/head
Tuned by Tobz here in Denver, CO

 

Did you happen to mess with the Biss when changing your iac valve ?

 

Did you tighten the throttle cable? As things expand it can pull it tighter and slightly open tb as I've experienced.

 

Ok so I tired the throttle cable. It actually helped a lot with the idle! thanks for the tip. I think I just need to take it back to the tuner and have him re adjust the bliss screw

 

so it was caused from the cable?

 

Mine does the same thing. Never figured it out

 

Having the same problem, anybody?

 

I think a big part was the throttle cable being loose. So now if I come to a complete stop itll dropt down to 900rpm then AFR'S will read 10.0 then shoot right back to 14.8-15.0. So im kind of stuck on why itll do that as well. Something still seems a little off.

 

bump for info. Having the same issue after just replacing my IAC valve. Idles around 2k and won't go down.

 

Did you clean the throttle body plate? Don't as it will cause high idle. It could be your BISS and/or your idle settings in the tune.

 

Hi I am new here
What is IAC and BISS
I have a Galant, MK VI with the same problem of Hi idle when hot.
The engine is 4G63 Non Turbo Year 2004
Please help out
Charles

 

IAC = Idle air control valve
BISS = base idle set screw
As far as location, IAC should be somewhere on the intake manifold, usually below the throttle body. BISS is on top of the throttle body usually under a rubber seal.