Strange idle

[AWD-Wrecker]

i have a 92 talon TSi Automatic.
i picked it up with a snapped timing belt and rebuilt the head
with stainless steel valves.
i had the head resurfaced but didnt get the valves matched,
it runs nice with no problems.

But I cant seem to maintain a steady idle.
i can mess with the throttle cable and that screw on the manifold all day,
but it idles different when its been driven for 10 or 15 minutes.

i set it to idle at 1000 rpm cold,
then it idles at 1750-2000 hot.

is there a stock setting i can put it to?
im sick of having to keep a screwdriver in the glove box and adjust it several times a day.
Any help would be greatly appreciated.

 

[DeadsEvolution1]

You should Read this sounds to me Idle surge

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[kthackst]

Its not idle surge. At least not from the sound of his explaination. Adjust your throttle cable when the engine is hot. The cable will expand and pulls the TB open a hair when it gets hot. And at idle the slightest opening of the TB will cause the car to idle real high. The ICV will help with the idle when the car is cold.

Same thing happend to me and now it is fixed. Also make sure to set your BISS screw to when the engine is up to temp not cold.

 

[okm12346]

Check for vacuum leaks - EGR, vac lines, TB gaskets, BISS o ring, Leaky PVC. See if you can swap out the ISC and do a full TB tune up - SAS, TPS and BISS

 

[AWD-Wrecker]

Alright thanks alot guys.
i have it idling at about 1300 hot now (higher than i would like but owell)
and she idles at about 650 in gear with my foot on the brake.

ill do a little more fine tuning and let you know