Holley Carb Question

[MDC]

I have a 600 Holley w/ manual choke that was running fine until today. I sprayed the engine with degreaser (air cleaner was on) let it sit for about ten minutes then rinsed it off with just a hose. Drove around the block and it acted like the throttle was stuck open. Got home and checked it out. The return spring is still attached and I even tried to push the linkage forward, but it's all the way down. I backed off the idle speed adj screw (all the way)which made very little difference. It has a mech choke that has never been connected since I have owned it. I flipped the linkage to close the choke and after a few seconds it died. Started it back up and tried to adjust the idle mixture which didn't seem to make any difference. I was able to close it all the way and it never shut it off, but I can adjust it out to make it run richer.
Is my carb fried? Or is there something that would make this thing run at a high idle all of a sudden?