Choke Issues

[DaveHess]

I have an '86 Power Ram (D100) with a 360 2bbl. My routine for starting it has been one pedal push to the boards to set the choke, hit the key, wait till she lights and then a quick shot of throttle to smooth her out. This routine would cause the truck to keep dying until she was warmed up. In other words, no high idle.

This past weekend, I tried the one pedal push to the boards, hit the key and see what happens. After some playing around with the high idle adjustment screw, set it at 1500 RPM and she purred great at high idle with the choke closed (or more correctly, barely open). As soon as I give it throttle (still ice cold engine), the choke goes wide open and my high idle goes away, and she struggles to idle until she warms up.

What I don't understand is, what is supposed to keep the chike engaged until the engine comes up in temperature? There is a Vacuum line to a dashpot and a piece of linkage connected to the choke. The linkage I know is driven by a coiled spring in the intake manifold. I thought as it got warmer it moved and opened the choke. Am I wrong? The vacuum I am guessing is designed that as vacuum drops, it allows the choke to open momentarily such as under acceleration.

What am I missing here guys?????