Thanks for all of the information. I opened the small quarter inch manual valve (3 turns) last night. The jack went extended and retracted at normal speed. In fact it came up slightly faster than the other working jack. I don't believe the needle valve is getting enough stroke to fully open the port. Looks like I'm gonna have to bite the bullet and order a replacement valve.
DougRainer - I did pull the solenoid last night, the valve has a wire mesh filter screen around it, didn't find any contamination that would cause any restrictions. The valve did come out without any visible damage to the seals and didn't appear to leak after I replaced it.
I do appreciate all of the feedback, I think it's great how people on this forum are so willing to share their knowledge and experiences.