Idle issue - 411 code

[SHOGUN88]

I've been having an Idle issue for a while. For starters if the car is cold and I proceed to start driving it without letting the idle come down, it will stay quite high (1400-1500) until I come to a stop and let it come down then it idles somewhat normal (900). At the same time the idle it not as smooth as it should be, very slight stumbling. Initial throttle response sometimes stumbles aswell.

I am getting this code;

411 (R) Idle speed system not controlling idle properly (generally idle too high) - ISC

I did have the intake apart a while ago and have checked for vacumm leaks by spraying brake cleaner everywhere to no avail. I cleaned the maf and have replaced the following parts recently:

IAC, TPS, all vacumm lines, intake gaskets

any help would be great, thanks

 

[SHOGUN88]

Update - it has developed a slight miss as of lately. A while back I did have one of the wires crossed on the coil, but not for long before I realized it. Could that have caused any damage to the wires or coil?

 

[rubydist]

idle speed and idle miss are almost certainly unrelated.

the idle speed issue is a bad iac, sticking.

connecting plug wires wrong on the coil will not damage the coil.