i found the screw on the front drivers side and its the one that moves the throttle back and forth. now on all the imports i have worked on with throttle bodies (ones similar to tpi) they have 2 idle adjustment screws. there is one that moves the throttle and then one that lets air enter around the throttle bores( i would post a pic but i don't have one on me at the moment):lala: any way is that the only screw to turn to increase the idle?

 

There is a Idle Air Control motor on the side of the TBI unit. It is a copper/brass color. It's on the passengers side near the rear. This motor adjusts the idel speed of the car by means of increasing or decreasing the amount of air that can flow into the engine. I guess this would be similar to the screw that adjusts how far open or closed the throttle blades can go. But this motor..unless it's not working properly, should do all the adjusting that is needed.

Are you trying to increase or decrease the amount of idel?

 

On most of the fuel injected GM cars I have seen (TBI, TPI and turbo Buicks) the screw adjusts the throttle opening for air bypass by the IAC. It does not set the idle speed as that is programmed into the prom. You should only adjust the screw to get your IAC counts back into range.

 

i just needed a little increase maybe 2 or 3 hundred rpm's i did it with the other screw but that seems to me that at idle it would use more fuel because the throttle blades are open more???

 

Did you use a scan tool to make the adjustment?