What kind of grass do you have? Were you irrigating this past year during the drought?

Thx for the follow up. Both St. Augustine and Bermuda. The yard is irrigated, but does get pretty dry late summer in compliance with local restrictions.

Can you post up some pictures? Have you had a soil test? SA and Bermuda require different cultural practices.
I would focus on getting the Bermuda going (I don't do SA).
Have you scalped it and bagged the clippings. That will help kill the weeds and jump start the Bermuda. I had a bad bought of weeds this winter too, despite using Amaze. I just spot sprayed with Celsius yesterday.

I have added some photos and placed them in a public dropbox gallery. I wasn't sure if the built in image upload would allow for multiple files. I have not tested the soil but do have access to a good soil tester. The Bermuda is in the full sun parts of the yard and the st Augustine in the less sunny. I will scalp the yard - i did this last year too and that stresses the weeds out pretty good. I am not able to bag the whole yard - too big - but i do sometimes bag areas like the front yard for example.

thx for the follow up. this is the link to the 8 photos https://www.dropbox.com/sh/6po3dqb9iopz0ap/9dPXyQdJ2G

I didn't know Dropbox would do that. Cool. You cannot upload multiple files but you can link to multiple Dropbox files in your Public folder. You have to know one line of HTML coding. There are other posts about linking to photos elsewhere in GardenWeb. They even have a test forum.

We really need to know where you live. Anyway, you do have the full gamut of weeds. It looks like your lawn started out as bermuda. Can you tell or do you know? What do you want? Bermuda or St Augustine?

You say your yard looks like a vacant lot. Nothing in those pictures says, "vacant lot" to me. It looks like you live in a plush park.

You say you have 37,000 square feet. Where? Did you mean 3,700 square feet? Because that's about all you have pictured.

Back where you have plenty of shade, the only choice of grasses is St Augustine. It will grow nicely unless it is more shady than it appears. First you have to get rid of the weeds. The product to use is Spectracide

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This is a foliar spray, not a soil drench. Drench the soil and it will damage, but not kill, the St Aug. Be careful to keep the spray off of the bermuda because it will damage that. For weeds in the bermuda you will have to try something else. Or you could let the St Augustine fill into the bermuda.

Once you get the weeds out of the St Augustine, you need to start caring for it properly. I think the problem with your plan from last year was sticking to specific dates rather than looking around at your situation. Alternatively it could be your soil microbe population is tired and run down. You can fix that with a dose of alfalfa pellets (rabbit chow) at 20 pounds per 1,000 square feet at least once a year. General care for St Augustine includes mowing at your mower's highest setting, watering deeply no more than once per week during the hot part of summer, and fertilizer 3x per year if you want to use Lesco or up to 5x per year if you want to use alfalfa pellets.

The location is Dallas Fort Worth. The yard is 37,000 square feet - 1 acre less house, pool, driveway. I'm not too concerned with eliminating the spring weeds. The damage is done, its too costly to remediate, and soon they'll be gone when it gets hot. My primary concern is that fact that I have closely followed a system and applied product when and how directed and have very poor results. Now I am concerned my summer weed pre-emergent will fail me. I will complete the solid test as recommended and may also try another brand of lawn treatment.

My primary concern is that fact that I have closely followed a system and applied product when and how directed and have very poor results.

So have you given up on all systems or just the Lesco system?

Many of us (on another forum) found that we got into a yo-yo type of program. We ended up applying more and more chemicals and getting less and less good news about the lawn. Finally we tried, as a last resort, organic fertilizer. I'm trying to think of anyone who was not surprised at the good results. Nope! Can't think of anyone. There seems to be some kind of soil depletion that occurs when you apply chemical ferts over time. The one or two apps of organics and all is better.

I have never had good luck with preemergents whether chemical or organic. I have had much better luck with proper watering and mowing height as I described above.