Idle Problems

[95AWD6Bolt]

I am having a problem with my idle and i dont know how to fix it. When i first start my car it idles around 12-1300 but then after a few seconds it slowly rises to around 2000+. I usually let it warm up for 2-3 mins and then when im driving the idle will stay around 2000+ rps and sometimes it will drop below 2000. After about 15 mins of driving it sometimes comes down to a normal idle around 750 (where dsmlink has it set to). If i drive it for a while then turn it off and go into a store or something i will come out and it wont stay started. It will turn over and then just lose it. Sometimes i have had to adjust the biss screw to get it to stay running but yesterday i just pushed the gas in and kept it reving around 1000rpms and it stayed on after about 30 seconds of that. I just replaced the isc with a brand new one. I have a 2g with a 6bolt, ross pistons eagle rods, stock fuel, stock turbo, stock intercooler, and dsmlink. Can anyone help me with this?

Also i have noticed that one of my cooling fans is all burnt up (couple fins are melted) so obviously my engine had to of overheated before i got it. If the guy who had the car before me never replaced the head gasket or checked if he bent valves could this be causing the idle?

 

[GSX Spyder]

vac leaks anywhere? if thats not the case I would make sure of the size of the injectors and the setting that is logged in the dsmlink.

steve-o
master tech stuck in the newbie crowd.

 

[95AWD6Bolt]

the setting of the injectors or the setting of the idle?

 

[gringo72884]

try a boost leak test, check the idle speed control motor(voltage), make sure your spark plugs are properly gapped. Just a few suggestions

 

[Fayt]

My idle fluctuated like that when I had a few minor boost leaks. My BOV was leaking a little around the seal to the IC pipe and it'd do the same thing.

Warped head/headgasket would cause a lot more than idle problems. Any oil spots in your coolant/coolant in your oil? Any smoke? You can confirm a headgasket problem with a compression test.