[Rick Parker]

The Holley is overall a good piece to work with, if not it wouldn't have been used as a pattern for other knockoffs. It has some shortcomings that can be rectified with a little work. As Jack 21 said, the idle transfer slots have to be set properly as a baseline. If they are holding the throttle plate open too much the main sytem will be fuctioning was you attempt to adjust it with the idle system, (not good, little effect). If you have a very aggressive cam a 4 corner idle sytem will be required to get an idle that you will be satisfied with because the engine will have low vacuum thus creating a weak signal in the idle circuit. A standard double pumper can be converted to 4 corner idle with the existing parts "IF" you understand how the carburetor functions, where the fuel needs to flow and if you have the right drill sizes, otherwise buy the parts to convert your existing carb. It smooths out the idle considerably and makes for a crisper transition off of idle.
From the description of the problem I think the timing of the fuel delivery is questionable. The set of cams that are available for the Holley's will help a lot. They are colored differently for identification. Try choosing a carburetor cam that has a "Faster Delivery" injecting the fuel earlier to "cover up the hole" created when you depress the throttle.



Rick