Dangerously High Idle

[Jonny J]

So after owning my Gst for a couple months now i finally decided that i would try doing some basic upgrades to it. So I bought hard piping (intake and intercooler) and the guy had the flange welded so I was forced to use his purple dumb greddy BOV instead of my turbox. anyone famlier with this bov I only hooked up the top nipple on it closest to the adjustment screw, I do not know what the other one is for. but after hooking everything up and starting my car its been idling prettyyyyy high. 2000-3000 range. Ive checked on here and people say check the throttle cable, i did. I cleaned my Iac sensor to. Ive checked for boost leaks also... couldnt find none.. I litteraly swapped out pipes and that was it. My car NEVER idled high before this. My guess is that something is holding my throttle open? I dont know. Any suggestions please? Im fricken scared to drive this thing with the idle creeping up constantly.

 

[ricktb]

I noticed my idle went up to over 2500 at times when under hood temp went up.. my theory to this is that the throttle cable jacket expands making the throttle cable tighter within the jacket, and it can no longer allow the throttle plate to close properly. My fix was to give some slack to the throttle cable with the 10mm bolts and adjustment bracket up on the top and its worked ever since, I have normal idle engine now (800). Sometimes the cable gets rusty inside the jacket and does not slide easy on older cars, for this you may want to replace the cable entirely.

When you notice the engine idling high, attempt to manually close the throttle plate by hand and see what is holding it open.. you might be able to troubleshoot by messing with it a little. Heck maybe something inside the throttle body is physically holding the plate open you never know pop it open take a look.

 

[crazyquik22023]

If the throttle is stuck or being help open you should be able to verify this by just looking at the throttle plate with the car off. As ricktb said make sure the cable is adjusted properly and not too tight. Also read this article to get some other ideas as to what can be causing your "high idle". Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge) Check everything in that article and make sure you are POSITIVE you have no boost/vacuum leaks and you will probably find the issue somewhere.