If your intake manifold runner is stuck open the best thing to do would be to take it to a licensed dealer or mechanic, they are not easy fixes and shade tree mechanics should really leave this one to the pros.
I assume that you mean throttle body not intake runner. The intake runner is the part of the intake that "runs" down into the intake ports of the head. If your valve is stuck then just clean or rebuild it.
You may have to remove the manifold and attempt to replace it. But most likely you can simply take some cleaner and remove the varnish making it stick.
You should really fix this pretty quickly. If your intake manifold runner is stuck open then you will have some long lasting problems that will cause you to have future issues.
