Question
Hi, Matt. It wouldn't let me ask a follow up question, so I have no to go this way again.

Anyway to answer your question of "The only thing I can think of with the valve is has a severe flaw in the lower half of the case and is just not capable of opening completely. Have you removed the tops of the sprinklers with the water on just to check the flow to them? Or try placing your thumb over the nozzle of the operating head, the next head inline should pop-up. If it doesn't the you need to start checking the fittings at the sprinklers. I should have asked first,Is the system new or did you just have the valves changed? Did this zone ever work?

Here is my answer The valve was working fine all summer, now this year its not. I removed the top of the the 2 non working sprinklers and nothing. The only sprinkler working out of the 3 is the sprinkler closest to the valve. The system is not new, I just didn't like the valves I had in there, they were hunter and all 4 leaked, so I went with rain bird, as for the problem you suggest with the fittings @ the sprinklers, I will check that when I get a chance, but I actually removed the sprinkler that doesn't come on while the zone was on and still nothing, so no water is even getting to the sprinklers that aren't working. As for the zone itself, it has always worked and have never had a problem with any zone doing this before, in fact have never had this problem before. I was thinking it might be a leaky pipe, that is why I let the zone run for about 20 minutes thinking I would notice a puddle develop somewhere but didn't. I have had a broken pipe before and you notice it usually right away. Talk you later.

Answer
Thanks for the complete info. I have a better picture of the situation.
It sound to me something got into the piping during the valve change over. It isn't uncommon for a stone to roll around for days or months before getting stuck in a fitting.
I would open the fitting at the first head, after the sprinkler. Or just cut it a foot after. A coupling is easier to deal with that the sprinkler fitting. Unfortunately, it's a process of elimination. If there is a positive from the event it is your very gratified when you do find the problem.
Good luck, if you need anything else, be sure to ask.