Testing for air suck...
One quick way to check this, look at your clear fuel filter, how big is the bubble? I recently had problems like you describe after some fuel system tinkering (injectors etc., but not DV) If you have much more than a small bubble, you are leaking air. I realized mine was over half full of air. I was at about 1/4 tank at the time. I filled up and cracked the line loose downstream of the filter. The filter filled up with fuel, and stayed full, and the car straightened right up. I will be changing my tank screen when I run low on fuel again. I am also in the SW (Northern AZ) I replaced all of my rubber lines first thing. They were hard as a rock and brittle. One could easily be cracked, or not making a good seal to a hard line. It sounds like you may have already taken care of that. Also, did you change your filters AFTER your purge, if so, fine, if not...I'd try it.
Best of Luck,
JDC

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1990 124,128 602,962

Beware the hobby that eats.
Benjamin Franklin