weird problem with my idle

[dropt4]

I have a wierd problem with my idle.. When I first start the car it takes a while to get warmed up, but since it is highly modded I get that, but when I dirve around town like normal the car is fine.. If I get on the freeway for say 20-30 minutes doing about 70mph and then come to a stop somewhere my idle will stick at like 3k and not go down.. Is this something electronic that is going out and needs to be replaced? Never had this happen on my old GST, but it was also stock.. Any suggestions?

 

[4g63Powered]

Sounds like the throttle is sticking. When you open the throttle by hand, can you feel it bind or catch at all?

 

[jusroln]

Couple common issues could be causing your problem. As stated before, check your throttle cable, make sure it is not sticking. You might need to adjust the tension in the cable. Also, your trottle body plate might not be closing because of a dirty TB. Check the ring around your BISS screw on the throttle body to make sure it isn't leaking. Also could be the ISC (Idle Speed Controller).

 

[thorlief4g63]

I have a similar issue and it is because I dont have an Idle Speed Controller. Mine only goes to 1.5k but I know exactly what issue your having.

 

[dropt4]

well it is just kind of wierd that it only does it on a long distance highway drive.. It is fine around the city.. But I will check out the TB though

 

[dropt4]

well it does not look like it is sticking, so now what?

 

[Artago]

If you have cruise control then check the cables. If they seem too tight then back the screw out a bit to loosen them.