F'n EGR....but its required.
Well, I think I figured it out:
The vacuum amplifier must be bleeding a small bit of manifold vacuum into the EGR as it was raising it 2mm without any venturi idle signal. Probably a bad seat in the vacuum amplifier (serviceable?) . So I worked with what I had and found that the EGR pintle was indeed adjustable! So I measured how much it raised with the residual vauum from the amplifier and lengthened it a tad more so now even with the bleeding vacuum, its still remains seated and now my idle has totally cleaned up @ 22 inches. Timing spot on at 8 BTDC and the Thermo switch did in fact hold under 122F. Life is good ! Here is a vid of the adjustable EGR valve (great to dial in the opening) and another vid of the engine at idle with the EGR fixed. Its a loud engine by nature as it has pulse air injection, sounds like an outboard motor right nest to the intake snorkle or worse when the air cleaner top is off.
Well, I think I figured it out:
The vacuum amplifier must be bleeding a small bit of manifold vacuum into the EGR as it was raising it 2mm without any venturi idle signal. Probably a bad seat in the vacuum amplifier (serviceable?) . So I worked with what I had and found that the EGR pintle was indeed adjustable! So I measured how much it raised with the residual vauum from the amplifier and lengthened it a tad more so now even with the bleeding vacuum, its still remains seated and now my idle has totally cleaned up @ 22 inches. Timing spot on at 8 BTDC and the Thermo switch did in fact hold under 122F. Life is good ! Here is a vid of the adjustable EGR valve (great to dial in the opening) and another vid of the engine at idle with the EGR fixed. Its a loud engine by nature as it has pulse air injection, sounds like an outboard motor right nest to the intake snorkle or worse when the air cleaner top is off.