Engine Idle Surge!! Help!

[Glenn Woodard]

So I recently purchased a 95 GTS. Drove it about 250 miles home and it ran find for about the first 200 miles. Started having a little misfire at crusing rpm. replaced the plugs and wires and the misfire is gone, but now it has an idle surge. Can't figure out what in the world is causing the surge. Any ideas? Car still runs like a scalded ape above idle but its just kind of rough at idle rpm.

 

[addermk2]

need to know whats done to the car.

 

[Glenn Woodard]

Full exhaust including shorty headers. No cats. MSD ignition, underdrive pulley, cold air intake. EGR to header tube is missing, but the header bung is capped off. Egr valve is still hooked up but the red and green vaccum lines are capped off.

 

[Bam Bam]

Do a base idle reset. When I did this recently I also pulled battery cable and drained the computer first. Get some help start car wait until fully warm. Unplug the Idle control valve, TPS, and spout connector. If motor dies plug back the idle control valve and twist down idle set screw about turn and half. Start car then unplug again should be idle up slowly turn down idle screw until reach desired rpm. Kill motor plug everything back up and re start.