High RPMs during cold start up

[efrider89]

I was wondering if anyone could help with a problem of when I start my 1g Talon up and the RPMs are just sitting up around 2500-3000. It is only this high when I first start up the car until it gets normal operation temp. Also, since I have had my Talon the idle has also was been going up and down when the engine is cold. I know it is not the IAC cause I replaced that not to long ago. Is there a cold idle value or other kind of sensor on the intake manifold that I need to replace?

Thanks
Chris

 

[majik2k5]

First things first, try grounding the nessecary wires and then adjusting your BISS screw.

 

[Tevenor]

Do a search for FIAV. It's the Fast Idle Air Valve. Its purpose is to raise the idle when cold to allow it to heat up faster and as the engine heats, the valve cuts off the air supply to take it back to normal ISC idle. Pretty common problem.

 

[efrider89]

Ok, i will look into the FIAV, is this part easy to replace? That makes sense just as you were talking about when the engine is cold at start up.

Thanks

 

[MrBoxx]

Beat me to it.

It's not really broken, per se. It's JOB is to raise idle. You can reroute or block off the coolant lines going to it and not have a functioning FIAV anymore, which would bring start-up idle back to stock no matter what the temp is.

TPS, ISC, BISS, etc can all probably create erratic idle.