Originally Posted by Que89YJ
5000 rpm is a crazy high idle. I dont know how it is even possible with the throttleplate closed. Can you start it up and out your hand over the throttlebody to stop any air from getting in and see if it is still able to run. With the butterfly closed inside the throttlebody there is no way, and I mean absolutely no way that it should be able to pull the air is takes to idle or run at that kind of rpm. Also Jack, if you would please fill in the info on your profile.
Q is right, it can`t supply enough air to hit 5000 rpm with the plate closed. On my stroker I had to dril a .1094 hole in the throttle plate to ADD more air.