Sounds like the idle control unit is bad. They love to go bad, as well as be expensive to source. 
Mmmmmm........... Vanagons........

-craig 

On Jan 3, 2014, at 8:27 AM, JRodgers <jrodgers113@GMAIL.COM> wrote:

> After a lot of monkeying around, I finally got Ol' Red to run properly -
> but not exactly by the book. If I leave the idle stabilizer valve (which
> hums as it should) disconnected, the engine starts and after a warmup -
> idles delightfully around 800/900 rpm.
> 
> When I do a cold start with the ISV connected - the engine over speeds.
> Not good right from a cold start. Should come  up to 1200-1500 and then
> drop back as it warms. But it goes well above that. I won't operate
> under those conditions so just keep it disconnected.
> 
> Anyone with any ideas as to how to adjust this out to get it to function
> properly with no runaway speed on start up?
> 
> Thanks,
> 
> John