This subject is right in time for me I'm struggling with this on two different trucks, both have good shaft movement on their own but no matter how I attach the spring I get no movement. When I had the manifold for the 261 on the bench evereything moved fine when I applied some heat to the spring but mounted to the engine with engine fully warmed up I get no movement and the flapper does'nt close! the other truck same thing, no spring movement when the motor's hot. Is it possible the springs I bought are bad?Any suggestions?
Try giving it some throttle and watch your counterwieght.
I warmened my engine up in the garage and the valve didnt move. I grabbed the throttle rod a goosed it a bit and it moved closed,Heat off.
Checked it after a short drive and it was still closed or heat off.