Losing power on fast left turns

So my project 1.6 beater is having problems. Besides the high idle issue, I'm noticing that when I make a fast left turn (full throttle) at anything under a half tank, it feels like the car is starving for fuel. Give it a couple of seconds and the power comes back on. I haven't run into this when the tank is full, but when I get about halfway down it starts to happen. This really sucks when your are darting out into flowing traffic and you are almost stalled. Anyone have any ideas as to the cause (fuel tank, fuel pump?)

Sounds fuel pump related to me...partially clogged perhaps?

I forgot to mention that the car has 257k miles and unknown service history. The fuel gauge is always incorrect, fill it up and it goes to all the way empty for 20+ miles, and will then rise up to 3/4 and work its way down, but never read accurately. I keep thinking fuel pump though.

I'd do the filter first, just because its easier to eliminate and ought to be done routinely. AFTER that (not at the same time, remember the scientific method), pull the fuel pump and discover that it is near-death AND has a clogged pickup. Change the assembly and flush out that nasty junk at the bottom of the tank, then you're good... except you'll be wondering how much crap got into the fuel lines, so you'll flush them too. Then it will occur to you that the fuel rail might have gotten something in it that made it past the filter, and god only knows how gummed-up the injectors are... ::Banana::

Was planning on changing the filter this weekend as a starting point. Yes, I'm fully expecting to start with the pump and work towards the injectors before I'm through. I may just pick up a DW200 pump and ditch whatever is in the car.

I'd just get a new to you replacement from Nissan/Mazda heaven (it's what I did). Unless you want to deal with an FPR, going high pressure is a waste of dinero.

When I swapped mine (which is no fun with a top and a roll bar btw), it came with a new sender, etc. so you might kill dos pajaros at the same time.

Mine did the exact same thing and I drove until it died on me. Ended up getting this at pick n pull for $50.
http://www.flickr.com/photos/106506928@N08/

Car stutters a bit when I accelerate so I still plan to replace filter.

Just ordered a used unit off ebay, and picked up a new strainer too. I'll see if that helps and go from there. I replaced the filter last weekend and that didn't make a difference.

Well, the gas gauge works now, but I still loose power on left turns and actually had it stall this morning making a u-turn. Injectors, FPR, Fuel Rail, lines, tank? Don't know what to tackle next.