The problem is not the flat pickup at the bottom. If it where, you'd have problems all the time - whether the tank was full or almost empty. The problem is the vertical sock filter inside the pump assembly. The filter, because it is verical, fills from the bottom (slight differential pressure from top to bottom of filter). When I removed mine, the filter was very dirty (probably clogged) on the bottom and got cleaner as you moved vertically. When you have a full tank, you can still suck gas as the top of the vertical filter is cleaner. As you get towards the bottom of the tank, you're below the clean and into the clogged portion of the veritcal filter. It can no longer suck, which 'sucks'.
My problems where exactly as you've experienced, including the inclined driveway problem. When I finally got things figured out, (I couldn't believe it was a bad pump), I just took the pump assembly apart and cleaned the vertical filter with a toothbrush and Fantastik. I also threw away the flat filter, which I had cleaned on a previous attempt to fix the problem.
I havn't had a problem for three months now. A word to the wise, I'd clean your secondaries immediately after fixing the pump, as, if the secondaries haven't opened for awhile, due to the fuel pump problems, their probably stuck closed because of carbon buildup. My IMRC cable broke within days of fixing the pump. I replaced the IMRC and cleaned the secondaries, and I have a 'new' car.
If I develop a clogged filter sock again, I'm going to just remove the it and forget about it.
Good luck,
Marvin Stockman
