hey guys, i need some help adjusting the idle speed, i have a 1990 350, and right know its ideling at about 1200 rpm, it was at 1700 but i adjusted the idle speed screw today, and it resulted in 500 rpm in the right direction, however adjusting it any more dosent do anything, what else can i do to get my idle speed down to 400 rpm, " thats where it should be right?" i think with it ideling that high results in poor stoping distances and premature brake failure as well as lowered gas milleage, am i correct?

 

Take a look at this.

https://www.thirdgen.org/techbb2/sho...hreadid=104279

 

You're adjusting it in drive, right?

 

what do you mean in drive?

 

If your car is an automatic, you should set the minimum air screw while the vehicle is in drive (D). If it's a manual, then you should set it to 750 (I think) while in neutral. Then set the TPS idle voltage. If the vehicle still won't hold a steady idle, make sure the IAC motor is functional and the passages and pintle clean. If your motor is modified (ei. cam, heads, etc) and setting the min. air and TPS aren't helping the idle (and everything else is good) then you know you're at the point where getting into PROM programming will help you. Everything else is just a band-aid.