I've been recently trying to get my truck back up and running and finally got it started today and it runs like crap and wont stay idling.

To keep it going I have to keep my foot on the gas and it wont rev past 3000 rpms. I pulled off the top of the carb and saw my passenger side butterfly valve is stuck open and it won't budge. What could be the problem?

It was spitting back pretty bad through the carb, could it have messed up the valve? and how could I go about getting it back into place

 

Odds are your carb has varnish build up on it from the gas sitting so long. Typically you can take the carb off and apart in some cases to clean all the parts up. Don't try to use a live or anything like that. It will just give you another problem. Carb cleaner is your friend.

 

Live = lube...

I would recommend taking it off to clean, I no longer recommend taking them apart however it can get very expensive when things start to go wrong.

Soak it spray scrub it. And free up all the linkage being very mindful of the cam locks so you're not trying to force against an immovable part. In some cases you'll have to rotate part "A" to be able to move part "B" and so on..

 

Good catch thanks