Originally Posted by caleb1563
I checked i have the right diaphragm i check the gasket its good i used an oring but it still does it i believe my primarys are closeing all the way im going to check further if there not what could cause it
Check the secondaries very carefully to be sure they are fully closed, it doesn't take much missalignment of the throttle plates for them to bind in their bores before they are truly shut. Also, check the seating lever adjustment screw that comes up from below the throttle shaft boss to be sure it's not cracking the secondaries a bit. It doesn't take much to really raise the idle, the smallest gap is plenty to cause this.
Also, check the seating on the manifold, if you overtighten the mounting nuts, the cast ears bend down which bows the throttle body allowing air to get between the gasket, manifold and throttle body. If you bent these there are two solutions one is to mill the bottom flat the other is to replace the throttle body as it is a casting so trying to bend the mounting ears backward if they are bent usually breaks them.