Bad injection pump?

[Sharpie]

I'm working on a '86 F350 with a 6.9L engine. I am getting fuel to the pump but the pump isnt even trying to build pressure. I have voltage to the pump plus this is the second used pump i have tried on the truck. How do I know the pumps are bad, for sure?

 

[Sharpie]

Please disreguard my previous post, I know better than to use - used s**t, that I know nothing about. The first pump was bad and the second also, seeing as how no internal parts were rotating. :nail:

 

[hesutton]

Sounds like a snapped shaft on both eh?

Heath