Steve, Donnie...someone help!

This is part II to the 3000 RPM idle. I got the idle down to a more reasonable level (1100 rpm) with the mixture screw (O2 unhooked). Cannot go any lower. It is not smooth and runs with a noticable miss and a surge when driven. I believe the O2 sensor is shot as the voltage when hot is less than .03 volts. The EHA a is about .25 - 1 ma also with the O2 disconnected and out the range of 5 - 15 ma when connected. With the O2 hooked up the idle jumps into the 2000 rpm range.

It appears that the sensors are working or at least trying too. I have a vacuum leak (must be big) somewhere. I can`t find it!
Spraying carb cleaner makes no difference. Is it possible that the air idle valve could be off? It clicks open/closed with twelve volts and has been cleaned. OVP is obviously working with voltage at the EHA. Air flow sensor readings are within the range. The idle contact for the throttle valve switch are bad, but I can bypass that.

I am contemplating removing the whole injection manifold and fuel distributor next to insure everything is correctly sealed and examine/adjust/replace the throttle valve switch?

Any thoughts please!

Tinker