My 77 20r is still bucking after a carb rebuild and i suspect the egr is bad. I have it removed and soaking in brake fluid. How can I tell if the valve is either stuck open or closed? Any details would be appreciated. These things are like 200 bucks new

 

Just see if the pintle moves when vacuum is applied to the small port on top. Use your mouth, a vac pump, or another vehicle running. Also see if you can pass air through the larger port when closed. Again by mouth. Vac applied to the small port opens the large port. Lots of times they get coked up and you never notice. If it leaks because it’s stuck partially open, it’s very noticeable in the way it runs in my experience. But more likely to be stuck shut than open. Bucking could be a lean condition caused by a vac leak or other problem with the carb.

 

Well its full of carburetor cleaner and when I suck on the small vacuum port, nothing leaks out. Its been sitting overnight full of cleaner and still nothing. What does this indicate?