Need help with idle

[comdep]

Hi everyone, I'm new here, thought I would give you guys a shot at a nagging problem I've been having.
I have a 1985 Ford E350 cargo van, 351 with 2 barrel carb. I cannot seem to figure out how to get the idle to come down. The choke seems to work fine, it will dissengage by hitting the pedal, just like normal. As the engine gets warmer, the idle gets faster and won't come down. The carb is new, as is the idle solenoid, which I've adjusted as far back as it will go. I can't find any vacuum leaks and the only thing left that I can think of would be the throttle linkage, but it seems to work fine. Other than taking it to a shop, I'm stumped. Any ideas? Thanks.