91 S10 Idle problems

My 91 S10 2wd 2.5 manual trans pick up was missing. I canged the plugs and wires and it ran better. With it running better now it idles at a very high rate. Like 3 times the normal idle speed. I was told about some type of idle screw on the carb but i can't find it. I was also told to look for a vac leak but i can't find one. Can someone help please. Thanks..

it does sound like a vacuum leak. check all your hoses again. just changing plugs wont do that.