Most likely this will fix it.^^
Also be sure your tank is clean, the fuel valve flows, the pump runs & flows, and the fuel filter flows. If the pumps not working, I think these also have a fuel pump relay that's known to go bad.
I'm assuming you made sure the interior light switch is off? You know, the one that usually says On/Door/Off.
The first thing I would do is check the door switches. If one is bad it could think the door is still open.
A primary injector would be a problem across the full rpm range, however slightly covered up on top by a functioning secondary injector(this is what I would be leaning to, given the information at hand). A bad coil would also be a problem across the board. A intake vacume leek is actually most...
As you said it clears out up high, so I would skip swapping the secondary injectors, and only swap primary injectors. Also check for air leaks by spraying something around the intakes between the throttle body and head.
Could be a coil, injector, or any related wiring causing your described problem. I would try to isolate the problem cylinder by disconnecting injectors one by one. Once you have determined the cylinder, swap the coil with one from a good cyl. If the problem moves to the other cyl you've...