I have been battling an ongoing throttle body problem. With the up and down idle. I never touched this screw however it is for some form of adjustment. I screwed it in and counted 2.75 turns. I backed it out the same amount. I started the car and again the up and down idle started but this time I screwed it in 1.25 turns and it ran smooth. During road test it started again. I screwed it in .75 turns and again it stopped the loping idle. What is the factory setting??

 

there is no factory setting. this screw is used to adjust the base idle speed. every car is slightly different, so it's probably adjusted a slightly different amount on every car. if you adjusted base idle wrong and just turn the screw with the engine running, you'll just cover up a problem elsewhere.