My monte carlo 1988 is having issues with high rpm I tried adjusting the screw that is on the left side on the carb I turned it counter clockwise 4 times and the rpms came from over 1500 to now 1300 in park. how many more time should I turn it or is there anything else I can do

 

My monte carlo 1988 is having issues with high rpm I tried adjusting the screw that is on the left side on the carb I turned it counter clockwise 4 times and the rpms came from over 1500 to now 1300 in park. how many more time should I turn it or is there anything else I can do (also after the first start up wait about 2 minutes and than hit the gas it will drop the rpms down to under 1000 after I go for a ride when I get back and park the car it jumps back to 1300 rpms I already backed the screw out 4 times)

 

I have a 1988 Monte Carlo ss with the 305 ho Engine with a Quadra jet. high idle issues, first fire up of the day the car jumped to 2000 rpms in 1 minuet tap gas paddle car drops to 1500 after other minute tap gas again the car drops to 800-900 rpms, go for for a ride after u come back and put it in park the car jumps to 1500 rpms backed out the idle screw on the carburetor on the passager side of the car total of about 3 1/3 to 4 turns counter clock wise go for other ride than park car is still at 1300 rpms now what do I do after this??

 

The idle screw is on the driver's side of the engine located by where the throttle cable connects. The idle screw turns clockwise to give it more rpm's and counterclockwise to turn idle down.Re-adjust the part you changed the setting on back to it's original position. Good luck