Weber Idle Circuit Mystery Options

[Conrad192]

I installed a new set of Weber IDF 40's on a bone stock '76 2.0

One of the carbs appears to have a dead idle circuit. (IMG:style_emoticons/default/WTF.gif) Car runs like crap below 2000 rpm's. It's happy spot is 3000. idle it's rough. Pull the wire on cylinder 1 or 2 and it makes zero difference in the idle. Pull 1 or 4 and it immediately changes the idle.

Here is what I know:

Floats height is set at 10MM

Carbs are spotlessly clean. Every orifice has been blown out with carb cleaner and check with guitar wire. Then blown out again with 100 psi of air.

New wires, spark plugs, rotor, distributor cap, and new 009 dizzy.

Removing plug and grounding to engine, the spark plugs are firing.
Compression is 130 lbs.

Valves are adjusted properly.



Air by-pass screws are FULLY closed.

Butterly is FULLY closed

The fuel adjustment screws were originally set to 2.5 turns out, but they make absolutely zero difference in the idle speed.

pump circuit works correctly.

I have absolutely no idea what is wrong with this carb. Given that they have never ran correctly it makes me wonder if there is a factory defect and the intersecting bores are not drilled properly.