I wouldn't mess with the airflow screw, those settings are made from the factory and you shouldn't ever have to mess with them unless there is some other kind of issue. Maybe one of your vacuum lines were damaged when you pulled them off or re installed them or maybe you miss one of your electrical connections. I have had this same issue. Take a long close look which I'm sure you already have to make sure that every connector is hooked up and that you didn't in some way damage one of your vacuum lines. After that if you get your timing anywhere near on the truck should run.
